DRISHTI [Issue 1, Q3, June 2020] 2

Table of Contents

FOREWORD 5 ZAWER BHUJWALA

FROM THE EDITORIAL DESK 7 JYOTSNA RAO & UMA MAHESWARI KRISHNAN

ABOUT US 8 UMA MAHESWARI KRISHNAN

JOIN MISI 9 MEMBERSHIP FORM AND DETAILS

IMAGING INFECTIOUS DISEASES – A CLINICIAN’S PERSPECTIVE 10 DR. VENKAT RAMESH, DR. SUNEETHA NARREDDY

MOLECULAR IMAGING IN INFECTIOUS DISEASES: A PRECLINICAL PERSPECTIVE 14 SHRIDHAR NARAYANAN & VIDYA SHRIDHAR

IMAGING STOCHASTIC GENE EXPRESSION OF HIV-1 18 SRESHTHA PAL, VIJETA JAISWAL, UDAYKUMAR RANGA

COVID-19- A WAKE-UP CALL FOR INFECTIOUS DISEASES IMAGING 21 GAYATRI GOWRISANKAR

RADIOLOGY OF COVID-19: THE BASICS 24 RON KORN

ROLE OF ARTIFICIAL INTELLIGENCE IN INFECTIOUS DISEASES 27 R.ELAKKIYA

MRI FOR IMAGING INFECTIOUS DISEASES 30 K. SUDHEER

PHOTOACOUSTIC MOLECULAR IMAGING OF INFECTIOUS DISEASES 33 RAJSEKHAR KOTHAPALLI

UPCOMING EVENT 37

WEBINARS

3 DRISHTI [Issue 1, Q3, June 2020] KNOW THIS TECHNIQUE - FISH 38 MAMATHA CHIVUKULA

SPOTLIGHT MEMBER 40 M.G.R. RAJAN

YOUNG PROFESSIONAL COLUMN: IMAGING – A TORCH IN THE DARK 41 SAKTHIVEL GANDHI

COVID-19 DIAGNOSIS & TREATMENT: WHERE DO WE STAND? 44 UMA MAHESWARI KRISHNAN

FOCUS INTERVIEW: DR. MURALI KRISHNA CHERUKURI 46 MURALI KRISHNA CHERUKURI, NATIONAL CANCER INSTITUTE, USA

PRODUCT REVIEW: MULTI-PHOTON LASER SCANNING MICROSCOPE 48 J. SEBASTIAN RAJA & GANESH KADASOOR

IMAGE OF THE QUARTER 52 J. SEBASTIAN RAJA

OPINION: AI IN INFECTIOUS DISEASE: PROMISE OR HYPE? 53 DEEPAK BEHERA

DRISHTI [Issue 1, Q3, June 2020] 4 Foreword

This inaugural MISI newsletter on the applications of imaging in infectious diseases comes at a critical time when we are rising to meet the COVID-19 pandemic, one of the greatest challenges of our times. The scientific community, including biomedical imaging scientists, are showing remarkable resilience in the face of this challenge. Molecular and functional imaging technologies have many important roles to play in meeting the challenges presented by infectious diseases, ranging from early detection, to monitoring response to treatment, to designing nanoparticle/image-guided therapeutic interventions for treatment. Several of these aspects are covered in the newsletter with contributions from leading researchers in the field. While the pandemic has negatively impacted almost every aspect of our existence, it has highlighted the importance of global co-operation in meeting such a challenge. This newsletter plays an important role in the exchange of ideas and advances in the applications of molecular and functional imaging to address important problems in infectious diseases.

Zaver M. Bhujwalla, Ph.D. Director, Division of Cancer Imaging Research William R. Brody Professor of Radiology Johns Hopkins University School of Medicine Baltimore, MD 21205, USA

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FROM MISI EDITOR OFFICE FROM THE EDITORIAL DESK… MISI would like to invite all its members to the inaugural quarterly newsletter. We are happy to be back in the fray although we know these are not the best of times. We wish to make a small beginning with this effort. The global pandemic has brought to fore like nothing else in recent times the importance of diagnosis. Scientists world over are racing against time to develop new drugs and vaccines. As a community we have a significant role to play in this endeavour. This is what made us decide that our first newsletter's focus being on infectious diseases would be apt. We have invited leaders from various fields to contribute who graciously accepted our request. We wanted to give a comprehensive view of current trends. We have showcased members and their work. We wish to choose other themes in the future for which we welcome your contributions and suggestions. Our focus will be on encouraging young researchers especially women scientists. We plan to conduct national and international webinars in the future based in various other topics for which we would like your suggestions with regard to choosing topics which will benefit our community most. We plan to work closely with WMIS (World Molecular Imaging Society) and FASMI (Federation of Asian Societies of Molecular Imaging) at various levels. We look forward to your active participation and request you to spread the word about our activities. Stay safe and healthy.

DR. JYOTSNA RAO &

PROF. UMA MAHESWARI KRISHNAN

[email protected] 7 [Issue 1, Q3, June 2020]

About us… The Molecular Imaging Society of India (MISI) was started in 2014 as the Indian affiliate of the World Molecular Imaging Society (WMIS) at the instance of Dr. Zaver Bhujwalla, Professor & Director, Division of Cancer Imaging Research, Johns Hopkins School of Medicine and the then president of WMIS. It was incubated by Piramal group with Dr. Swati Piramal serving as the first President of the Society. MISI was formally inaugurated as the Indian affiliate of WMIS on 9th March, 2014 at Piramal Research Centre, Mumbai.

MISI is a non-profit society registered under the Societies Registration Act, 1860 and Societies Registration (Maharashtra) Rules, 1971. The mandate of MISI focuses on all modalities of molecular imaging that includes functional MRI, Gamma camera, SPECT, PET, MR Spectroscopy, optical imaging, molecular ultrasound imaging, radioimaging and other emerging imaging tools. Currently, Dr. Jyotsna Rao, Consultant, Nuclear Medicine and PET-CT at Apollo Gleneagles PET-CT Center, Hyderabad, has currently taken over as the President of MISI and Prof. Uma Maheswari Krishnan, Dean of School of Arts, Sciences & Humanities, SASTRA Deemed University is the Secretary of MISI. Dr. Deepak Behera, Managing Director, Medical Imaging Consultancy, USA has been appointed as the Director, Executive strategy & Alliances. Four seminars have been organized by MISI over the years that covered all major molecular imaging modalities and their applications towards personalizing patient care. This quarterly newsletter is an effort to extend the reach of MISI to its members and associates, and serve as an interaction platform between practicing clinicians, basic researchers, engineers and industry to discuss, deliberate on the trends, concerns the community faces and use this as a platform to put-up the community’s concerns to the regulator. MISI would also like to nurture knowledge networking to enhance the chances of discoveries to be taken up for routine clinical practice. We look forward to your participation in MISI and its activities as a member. The registration details are provided in the membership form given in the following section.

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9 [Issue 1, Q3, June 2020] IMAGING INFECTIOUS DISEASES – A CLINICIAN’S

PERSPECTIVE

Dr. Venkat Ramesh, Dr. Suneetha Narreddy*

Apollo Health City, Hyderabad, Telengana

Introduction Some aspects have been highlighted As with any other branch of more than others. medicine, the objective of patient Respiratory infections evaluation in the field of Infectious Let us consider the diagnosis of Diseases (ID) is the correct diagnosis community-acquired pneumonia: The of the patient’s condition/illness. The presence of an infiltrate on a plain right diagnosis leads to the proper chest radiograph is regarded as the treatment, improvement in the gold standard for diagnosing Dr. Suneetha Narreddy is a M.D. patient’s symptoms and well-being, pneumonia when clinical and in Internal Medicine and and reduction of microbiologic certified by the American Board human “THE DIAGNOSIS IS NOT features are of Internal Medicine (ABIM). She is an infectious disease specialist suffering. One EVERYTHING. IT IS THE ONLY supportive. in the Department of Infectious famous ID In the case of THING!” - MAKING THE Diseases at Apollo Health City, professor keeps upper CORRECT DIAGNOSIS IS OF Hyderabad. She can be saying, “The respiratory reached at diagnosis is not PARAMOUNT IMPORTANCE infections: [email protected] everything. It is IN ID (OR IN ANY BRANCH OF imaging is not patients with the common cold. Plain the only thing!” MEDICINE, FOR THAT indicated in Considering the patients with films are also unhelpful due to poor MATTER). above, making clinically sensitivity and specificity. the correct diagnosed In stark contrast, imaging is diagnosis is of paramount importance uncomplicated rhinosinusitis. If paramount for the management of in ID (or in any branch of medicine, for obtained, findings consistent with fungal rhinosinusitis. It would suffice that matter). Radiology is central to acute rhinosinusitis on CT include air- to say that CT and MRI play a crucial this process and plays a crucial role. A fluid levels, mucosal oedema, and air role in the diagnosis of fungal balls, discussion on the role of imaging in bubbles within the sinuses. However, allergic fungal sinusitis, and invasive every infectious disease would itself these findings are nonspecific. Mucosal fungal sinusitis. constitute a voluminous book. Hence, abnormalities are common among Skin and soft-tissue infections this article will be restricted to the asymptomatic adults, and mucosal (SSTIs) more common uses of imaging in ID. oedema, air bubbles, and air-fluid Overall, the role of imaging is levels have also been observed in limited in SSTIs because the diagnosis

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10 Dr. Venkat Ramesh, Dr. Suneetha Narreddy*

and management are mainly clinical. characteristic features; such imaging scintigraphy play an important role in In the case of soft tissue infections, the may be used to establish a diagnosis of the diagnosis and management of best initial radiographic imaging exam osteomyelitis and/or to define the urinary tract infections in infants older is a CT scan. The most useful finding is extent of disease for surgical planning. than one month and young children. the presence of gas in soft tissues, In general, MRI is the imaging modality Most adult patients with which is seen most frequently in the with the greatest sensitivity for the complicated acute UTI in adults do not setting of clostridial infection or diagnosis of osteomyelitis; if MRI is warrant imaging studies for diagnosis polymicrobial (type I) necrotizing contraindicated, a labelled leukocyte or management. Imaging is generally fasciitis. This finding is highly specific scan, CT, or PET/CT is appropriate. reserved for those who are severely ill, for necrotizing soft tissue infections MRI is the most sensitive have persistent clinical symptoms (NSTI) and should prompt immediate radiographic technique for diagnosis despite 48 to 72 hours of appropriate surgical intervention. Other of vertebral osteomyelitis and epidural antimicrobial therapy, or have radiographic findings may include abscess. CT is a reasonable alternative suspected urinary tract obstruction fluid collections, absence or imaging modality when MRI is not (e.g., if the renal function has declined heterogeneity of tissue enhancement available. If neither CT nor MRI is below baseline or if there is a with intravenous contrast, and available, plain films should be precipitous decline in the urinary inflammatory changes beneath the pursued; however, plain films typically output). Imaging is also appropriate in fascia. demonstrate radiographic findings patients who have recurrent MRI has a limited role in NSTI only after the disease has become symptoms within a few weeks of because it is not as useful as CT for the advanced. If a plain film demonstrates treatment. The main objective of detection of gas in soft tissues and is vertebral osteomyelitis, additional imaging is to evaluate for a process overly sensitive. Ultrasound will only imaging is still warranted to assess the that may delay response to therapy or demonstrate soft tissue swelling but extent of disease and the presence of warrant intervention, such as calculus cannot determine aetiology complications (epidural or paraspinal or obstruction, or to diagnose a (infection/inflammation/tumour). abscess). Radionuclide scanning may complication of infection, such as a Bone and joint infection be useful if MRI is contraindicated renal or perinephric abscess. Imaging Imaging is invaluable in bone and because of claustrophobia or presence should be obtained urgently in joint infections. Plain radiography will of an implantable cardiac or cochlear patients with sepsis or septic shock to suffice in most cases of septic arthritis. device. identify any evidence of obstruction or It will not provide a definite diagnosis Urinary tract infections abscess that requires urgent source but can be used in the follow-up of Radiographic evaluation is control. patients. CT/MRI is valuable in case of warranted in all neonates with UTI. CT scanning of the abdomen and hip/sacroiliac septic arthritis. The first step of this evaluation is renal pelvis (with and without contrast) is In cases of non-vertebral ultrasonography to identify structural generally the study of choice to detect osteomyelitis, imaging should begin abnormalities. Also, voiding anatomic or physiologic factors with conventional radiographs of the cystourethrogram (VCUG) is associated with complicated acute UTI. involved area. A more sophisticated recommended to evaluate for CT, without contrast, has become the imaging modality should be pursued vesicoureteral reflux (VUR) in standard radiographic study for for patients with normal radiographs neonates with abnormal renal demonstrating calculi, gas-forming or radiographs suggestive of ultrasound, non-E. coli pathogen, or infections, bleeding, obstruction, and osteomyelitis without definitive recurrent UTI. USG, VCUG and renal abscesses. Contrast is needed to

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11 Dr. Venkat Ramesh, Dr. Suneetha Narreddy*

demonstrate alterations in renal location of an abnormal signal can COVID-19 perfusion. CT findings of sometimes be suggestive of specific Chest X-ray may be normal in pyelonephritis include localized etiologies: early/mild. At least 20% of hypodense lesions due to ischemia 1. Temporal lobe involvement is symptomatic patients will have a induced by marked neutrophilic strongly suggestive of herpes normal CXR throughout their illness. infiltration and oedema. When there is simplex virus (HSV) encephalitis, Although chest CT may be more suspicion for prostatitis, a trans-rectal although other herpes viruses (e.g., sensitive than chest radiograph and USG or MRI pelvis is preferred. VZV, Epstein-Barr virus, human some chest CT findings may be CNS infections herpes virus 6) can also produce characteristic of COVID-19, no finding A head CT should be performed (to this clinical picture can completely rule in or rule out the exclude a mass lesion or raised ICT) 2. Involvement of the thalamus possibility of COVID-19. In the United before LP in adults with suspected or basal ganglia may be observed in States, the American College of bacterial meningitis who have one or the setting of encephalitis due to Radiology (ACR) recommends not more of the following risk factors respiratory viral infection, using chest CT for screening or 1. Immunocompromised state Creutzfeld-Jacob disease, diagnosis of COVID-19 and (e.g., HIV infection, arbovirus, and tuberculosis. recommends reserving it for immunosuppressive therapy, Dengue and chikungunya hospitalized patients when needed for solid organ or hematopoietic encephalitis, seen widely across management. cell transplantation) India, may be considered in the When reporting chest CTs in 2. History of CNS disease (mass appropriate clinical and radiology patients with symptoms of COVID-19, lesion, stroke, or focal features. two systems may be used: infection) 3. In patients with West Nile 1. The Radiological Society of 3. New-onset seizure (within infection, MRI imaging North America (RSNA) has one week of presentation) demonstrates a variety of categorized features as typical, 4. Papilledema abnormalities in the basal ganglia, indeterminate, or atypical for 5. Abnormal level of thalami, mesial temporal COVID-19, and has suggested the consciousness structures, brainstem, and corresponding language for the 6. Focal neurologic deficit cerebellum with/without interpretation report. In patients presenting with abnormalities noted in the spinal 2. CO-RADS, for COVID-19 suspected encephalitis (altered mental cord and cauda equina. Reporting and Data System, is a status plus fever/seizures), CT 4. The presence of categorical assessment scheme for scanning is useful to rule out space- hydrocephalus may suggest chest CT in patients suspected of occupying lesions. MRI is sensitive for nonviral etiologies such as COVID-19, representing the level of detecting demyelination, which may bacteria, fungal, or parasitic agents suspicion for pulmonary be seen in other clinical states 5. MRI during post-infectious involvement. The substantial presenting with mental status changes encephalitis may demonstrate agreement among observers and (e.g., acute disseminated multifocal lesions mainly involving its discriminatory value make it encephalomyelitis [ADEM] or possibly supratentorial white matter well-suited for use in clinical a relatively rapid presentation of practice. CO-RADS 1-6 represents progressive multifocal MRI is more sensitive than CT for an increasing level of suspicion for leukoencephalopathy). If present, the the diagnosis of brain abscess. COVID-19 with one indicating no

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12 Dr. Venkat Ramesh, Dr. Suneetha Narreddy*

suspicion, and six indicating PCR tract sampling such as pyelonephritis in an uncontrolled positive (2,3, 4 and 5 represent endotracheal aspirate or diabetic with septic shock. low, intermediate, high and very bronchoalveolar lavage) PCR However, in almost all cases in ID, high-suspicion). testing. radiology cannot provide an Chest CT abnormalities are more 2. There is some evidence to etiological diagnosis. A patient with likely to be bilateral, have a peripheral suggest that CT may delineate fever, cough, weight loss, history of distribution, and involve the lower patients into two different contact with TB with a right upper lobes. Less common findings include respiratory phenotypes that need zone cavitary lesion may very well be pleural thickening, pleural effusion, to be managed differently. considered to be having tuberculosis and lymphadenopathy. 3. CT will aid in the diagnosis of until proven otherwise. However, the Chest CT abnormalities have also pulmonary thromboembolism sputum/BAL may reveal no cardiosis, been identified in patients before the [CTPA]. non-tuberculous mycobacteria or, development of symptoms and even The major caveat in the utility of once in a lifetime, Rhodococcus equi. A before the detection of viral RNA from imaging is ID is that, in some cases, patient with acute myeloid leukaemia upper respiratory specimens. radiology cannot provide a definite and a febrile neutropenic fever with a However, the chest CT may be normal diagnosis. Patients with enteric fever, ‘halo-sign’ on CT may have invasive (in up to 50% in one study) inpatients scrub typhus, leptospirosis, pulmonary aspergillosis but may also with early disease (CT performed < 2 melioidosis and complicated malaria have mucormycosis, fusariosis (caused days after symptom onset). can all have pulmonary opacities. In by Fusarium species) and CT chest can be considered to play some cases, radiology is invaluable: scedosporiosis (due to Scedosporium the following role in COVID-19: diagnosing a renal cell carcinoma in a apiospermum complex). 1. In patients with suggestive patient with PUO, the diagnosis of Until January 2020, a patient with symptoms but negative PCR, a progressive multifocal fever, cough, dyspnea and bilateral, ‘positive’ CT indicates possible leukoencephalopathy (PML) in a peripheral, subpleural ground-glass COVID-19 disease and need for patient with advanced HIV-AIDS and opacities would not have been repeat/better(lower respiratory the diagnosis of emphysematous considered to have COVID-19 too!

Interesting snippets - Milestones in medical imaging #1 Discovery Year Magnifying glass 1250 Light microscope used by Antionie von 1660 Leeuwenhoek Eye glasses 1752 X-ray produced by Wilhelm Roentgen 1895

Chest X-ray used to detect tuberculosis 1900

First contrast filled image of kidneys 1906

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13 MOLECULAR IMAGING IN INFECTIOUS DISEASES: A PRECLINICAL PERSPECTIVE

Dr. Shridhar Narayanan* and Ms. Vidya Shridhar

Foundation for Neglected Disease Research, Bangalore, India

Introduction great utility in understanding the Infectious diseases are one of the molecular mechanisms of a disease leading causes of death in the world. state. Several of the molecular Majority of these deaths are due to a imaging techniques including PET, few pathogens which include bacteria, MRI, CT, US, BLI and Immuno viruses, fungi and parasites. The PET/CT have been used successfully Dr. Shridhar has more than 16 significant increase in antimicrobial in the preclinical settings to improve years of drug discovery and development experience in Indian resistance (AMR) has become a our understanding of the infectious pharmaceutical industry in various therapeutic areas. Shridhar is a Ph.D. considerable burden on healthcare disease process. This article will in Pharmacology from Ohio State costs, especially as commodity provide a birds’ eye view of the University, and has post-doctoral experience in Neuropharmacology comorbidity in at the University of California, Los Angeles. Shridhar, a serial immune- THE USE OF MOLECULAR IMAGING entrepreneur, is currently Founder Director and Chief Executive Officer compromised TECHNIQUES WHICH ARE SIMILAR of Foundation for Neglected Disease patients. It is Research (FNDR), a not-for-profit BETWEEN ANIMALS AND HUMANS company with a mission to discover anticipated that and develop drugs for diseases of ALLOWS FOR A SEAMLESS TRANSFER the developing world. Throughout his the number of career, Shridhar has overseen the OF TECHNOLOGY AND CORRELATION deaths due to Discovery and Development of 18 clinical candidates in the areas of AMR would BETWEEN THE PRECLINICAL AND infection, oncology, diabetes, inflammation, and respiratory reach more than CLINICAL SETTINGS. diseases. As part of FNDR, Shridhar 10 million per has managed to raise donations worth 2.0 million USD from year by 2050. The impact of AMR could molecular imaging techniques that AstraZeneca, more than 1.7 million USD in grant money from the funding potentially be reduced by improved have been used in elucidating some agencies and around 5 million USD in of the critical characteristics of investment into preclinical and diagnosis and an enhanced clinical asset development by understanding of the molecular infectious diseases, which have a partners over the last 4 years. He may be reached at mechanisms involved in infectious significant contribution to the [email protected] Vidya is a microbiologist disease pathology. While several healthcare costs in India. The article with vast experience in technologies have been introduced in will also cover the use of molecular Actinomycete and Eubacteria Isolation, Culture Library for recent times to address this issue, one imaging techniques used in the drug Actinomycetes and Eubacteria, that has gained prominence is discovery and development process. Metabolite Library, Anti-infective Molecular imaging in Drug Screening, Fermentation Studies, molecular imaging. Database for culture Molecular imaging constitutes non- Discovery & Development Maintenance, Fermentation and Preservation. invasive technologies which have

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14 Dr. Shridhar Narayanan* and Ms. Vidya Shridhar

Drug discovery and development drug targets, understanding their correlation between higher FDG (DD&D) is a long process, and it takes distribution in tissues and interactions uptake and time to heal in lung lesions about 8 to 12 years and more than 1.4 between a potential drug and a drug of COVID-19 patients has been billion USD for a single drug to reach target. Reporter gene imaging suggested by Qin et al. (European the market. This is due to the more techniques have also been used as Journal nuclear medicine and than 95% failure rate when going tools for understanding this process. molecular imaging 2020). through the various steps in this Imaging techniques can be used to Bioluminescence imaging has been process. Any improvement in the understand the drug absorption, widely used to track organisms different steps involved in DD&D can distribution, metabolism and causing infectious diseases. In a result in significant time and financial excretion, which can define the utility murine herpes virus model, Kang et al. savings. of a molecular scaffold for a disease. have monitored CNS infection by the The process of DD&D starts with The ability to do longitudinal real-time virus using BLI. They have selecting a disease and a specific measurements in an animal model demonstrated that the brain is a site biological target responsible for the using imaging enables the efficient use for latent viruses. This finding has pathophysiological aspects of that of animals and helps reduce their implications in the understanding of disease. This biological target is then numbers used in experimentation. The the role of viruses in neurological modulated using either a small findings from such Imaging studies can diseases. molecule or large molecule (antibody) be readily extrapolated to a clinical Bacterial diseases resulting in resolution of the situation involving a patient. Tuberculosis caused by pathology. Multiple iterations are then Viral diseases Mycobacterium tuberculosis is the carried out in the lead identification to The emergence of the novel leading cause of death among identify a lead candidate. The lead coronavirus SARS-CoV-2 as a infectious diseases. India alone candidate is then optimized for various pandemic has created an urgent need contributes to more than 25% of the properties like solubility, tissue for suitable animal models and global TB burden, with more than 2.8 distribution, etc., using in vitro and in analysis techniques to aid the lakhs deaths every year. Significant vivo systems to identify a preclinical diagnosis and the treatment of this challenges with this ancient disease candidate. The preclinical candidate is disease. Recently MI Labs one of the remain the timely diagnosis of the evaluated in an appropriate animal pioneers in CT systems enhanced its disease and requirement of long-term model for safety, and toxicological preclinical U-CT system to allow for treatment with a combination of drugs, evaluation, which is required for non-invasive ultra-high-resolution six months for drug-sensitive and 18 to regulatory submissions, are imaging of the lungs. This enabled 24 months for the drug-resistant conducted. If there are no significant researchers to locate the pathological variety of TB. The traditional method adverse events, the molecule is processes occurring as a result of the of confirming TB with acid-fast nominated as a clinical candidate to be infection to the bronchi of the different staining and microscopy is time- tested in humans. animal models used, including mice, consuming and fraught with errors Molecular imaging is a tool that can guinea pigs and ferrets. due to a multitude of reasons. enable some of the steps of DD&D FDG PET/CT, which is a sensitive Blanc et al. have used MALDI-MSI process and make it more efficient. method to detect and monitor diseases (MALDI Mass Spectroscopy Imaging), Molecular imaging techniques such as such as viral pandemic can be a technique which is capable of PET or SPECT can be used in the early effectively used to diagnose and visualizing analytes in tissue sections phase of drug discovery to identify monitor disease progression. A using label-free technology. Sarathy et

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15 Dr. Shridhar Narayanan* and Ms. Vidya Shridhar al. have also used imaging techniques un-infected areas in the lungs of these the brain to compare the to study the drug distribution and patients. microvascular changes resulting in the found that the distribution of drugs in Slesiona et al. used pathophysiology of cerebral malaria. the necrotic lesions can be bioluminescence to demonstrate the Cabrales and coworkers used this heterogeneous and sub-optimal. Their persistence of Aspergillus terreus technique to demonstrate the ability to visualize drug distribution conidia. Such BLI technique can be importance of calcium channels in the along with the bacterial biomarkers used not only for the detection but also changes to cerebral microvasculature will allow for analyzing drug activity in to monitor the treatment success in in CM. They treated ANKA infected an entire system. This would be of long term infections. mice with nimodipine and showed a immense value, particularly in Parasitic diseases reversal in the changes to diseases like TB, which are plagued by Malaria caused by the infection microvasculature using the intravital problems with drug distribution at the with Plasmodium falciparum or microscopy. Others have also used this target site. Plasmodium vivax accounts for nearly technique to demonstrate the utility of Studies by Davis et al. using SPECT half a million deaths every year. Most exogenous nitric oxide (Cabrales) in imaging in mice infected with an of these deaths are due to cerebral reducing the vascular leakage engineered strain of Mycobacterium malaria and severe complications of associated with CM. tuberculosis expressing thymidine this disease. Cerebral malaria results Conclusion kinase have shown the power of this in several pathophysiological changes The use of molecular imaging technique to identify very few TB including a reduction in cerebral blood techniques which are similar between organisms within a granuloma. This flow, sticking of the RBC to the walls of animals and humans allows for a method can be used to test the efficacy blood vessels and metabolic seamless transfer of technology and of newer drug regimens which can be disturbances in the host brain. correlation between the preclinical used and monitored in humans. A mouse model developed using and clinical settings. This can provide Fungal diseases the ANKA (Antwerpen-Kasapa) strain for faster and appropriate treatment Aspergillus fumigatus causes a of Plasmodium berghei results in modalities being used in patients fatal lung disease called invasive cerebral malaria, which allows for resulting in better outcomes. pulmonary aspergillosis in immune- imaging of the brain. The characteristic References compromised patients. Rolle et al. have features of this model, including the 1) Durham TB, Blanco MJ., Bioorg Med Chem Lett. 2015 Mar 1;25(5):998-1008. used a novel antibody guided positron breakdown of the blood-brain barrier, 2) Cunha L, Szigeti K, Mathé D, Metello emission tomography and magnetic haemorrhage, reduced blood flow to LF. Drug Discov Today. 2014 Jul;19(7):936-48. resonance imaging to detect the fungi the brain, oedema of the brain was 3) Qin C, Liu F, Yen TC, Lan X. Eur J Nucl in the lungs. This technique allowed elucidated by Saggu et al. using Med Mol Imaging. 2020 May;47(5):1281- 1286 the researchers to distinguish the advanced MRI techniques. They also 4) Kang HR, Cho HJ, Kim S, Song IH, Lee TS, Hwang S, Sun R, Song MJ. Virology. bacterial and fungal lung infections, detected early changes which included 2012 Feb 5;423(1):23-9. and if used in the clinic could damage to the trigeminal and optic 5) Sarathy JP, Zuccotto F, Hsinpin H, Sandberg L, Via LE, Marriner GA, potentially guide the treatment nerves. These features are now being Masquelin T, Wyatt P, Ray P, Dartois V. regimen being administered to the explored for the early detection of ACS Infect Dis. 2016 Aug 12;2(8):552-63 6) Sarathy JP, Liang HH, Weiner D, patients. Pfister et al. have used hybrid cerebral malaria in humans. Gonzales J, Via LE, Dartois V. J Vis Exp. imaging technology using a Ga labelled Intravital microscopy is a 2017 May 8;(123) 7) Blanc L, Lenaerts A, Dartois V, siderophore to identify infected versus technique that allows for the long- Prideaux B. Anal Chem. 2018 May 15;90(10):6275-6282. term imaging of a particular region of

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8) Davis SL, Be NA, Lamichhane G, Zanini GM, Frangos JA, Carvalho LJ. PLoS Decristoforo C. Biomolecules. 2020 Jan Nimmagadda S, Pomper MG, Bishai WR, Pathog. 2013;9(6) 22;10(2). Jain SK. PLoS One. 2009 Jul 16;4(7) 14) Rolle AM, Hasenberg M, Thornton 17) Ordonez AA, Sellmyer MA, 9) Saggu R, Faille D, Grau GE, Cozzone PJ, CR, Solouk-Saran D, Männ L, Weski J, Gowrishankar G, Ruiz-Bedoya CA, Viola A. Am J Pathol. 2011 Maurer A, Fischer E, Spycher PR, Schibli Tucker EW, Palestro CJ, Hammoud DA, Sep;179(3):1104-9 R, Boschetti F, Stegemann-Koniszewski Jain SK. Sci Transl Med. 2019 Sep 10) Coban C, Lee MSJ, Ishii KJ. Nat Rev S, Bruder D, Severin GW, Autenrieth SE, 4;11(508). Immunol. 2018 Apr;18(4):266-278 Krappmann S, Davies G, Pichler BJ, 18) Jelicks LA, Tanowitz HB, Albanese C. 11) Cabrales P, Zanini GM, Meays D, Gunzer M, Wiehr S. Proc Natl Acad Sci U Am J Pathol. 2013 Feb;182(2):294-5. Frangos JA, Carvalho LJ. J Infect Dis. 2011 S A. 2016 Feb 23;113(8):E1026-33. 19) Jelicks LA, Lisanti MP, Machado FS, May 15;203(10):1454-63 15) Slesiona S, Ibrahim-Granet O, Olias P, Weiss LM, Tanowitz HB, Desruisseaux 12) Cabrales P, Zanini GM, Meays D, Brock M, Jacobsen ID. J Infect Dis. 2012 MS. Am J Pathol. 2013 Feb;182(2):296- Frangos JA, Carvalho LJ. Am J Pathol. Apr 15;205(8):1268-77. 304. 2010 Mar;176(3):1306-15. 16) Pfister J, Summer D, Petrik M, 13) Ong PK, Melchior B, Martins YC, Khoylou M, Lichius A, Kaeopookum P, Hofer A, Orjuela-Sánchez P, Cabrales P, Kochinke L, Orasch T, Haas H,

Interesting snippets - Milestones in medical imaging #2

Discovery Year Barium sulphate used as contrast agent for 1910 gastro-intestinal tract Radiographic imaging of gall bladder, bile duct 1924 & blood vessels Transmission electron microscope constructed 1932

Coronary artery imaging 1945 Panoramic x-ray imaging of jaw and teeth; 1955 dynamic x-ray imaging Fiber endoscopy 1957

Fetal Ultrasound 1960

Commercial Ultrasound 1965

X-ray mammography 1970

CT scanning 1972

Coronary angioplasty 1976

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17 IMAGING STOCHASTIC GENE EXPRESSION OF HIV-1

Sreshtha Pal, Vijeta Jaiswal, Udaykumar Ranga*

HIV-AIDS Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India

Ranga obtained a Ph.D. from Introduction splicing, etc. Gene expression noise The Jawaharlal Nehru University, School of Life Sciences, Delhi, India in 1990 for Here we describe how HIV-1 confers fitness advantage for the immunochemical characterization exploits gene expression noise to survival and has been shown to of the soluble antigens of Mycobacterium tuberculosis under the switch between transcriptionally critically influence probabilistic supervision of Prof. Rajiv K Saxena. active and silent states. Understanding fate decisions in viruses, During his first post-doctoral training with how this molecular viral switch works prokaryotes, and eukaryotes. For Dr. Indira K Hewlett, CBER, Food and Drug Administration, USA (1991-1993), is critical towards finding a solution to instance, increasing noise in he developed and optimized multiplex the ‘functional cure’ of HIV-1. stress-related yeast proteins amplification detection of HIV-1 and HIV-2 co-infections. During the second In provides a post-doctoral tenure with Dr. Gary J biology, THE APPLICATION OF selective Nabel, University of Michigan (1993- variability is advantage to a 1997), Ranga played a pivotal role in MOLECULAR IMAGING evaluating the efficacy of a gene inevitable, and fraction of yeast TECHNIQUES AT THE therapy strategy to protect HIV- every living cells to keep the infected T-cells in the first FDA approved SINGLE-CELL LEVEL HAS individual in a levels of stress- clinical study. Additionally, he developed an HIV-1 chimera promoter population is BECOME INSTRUMENTAL related proteins under the control of the CD4 enhancer unique. Much IN EVALUATING above a critical with an aim to restrict gene expression of therapeutic genes to the CD4 cell. of this threshold (Blake STOCHASTIC GENE He established an HIV laboratory at variability in a WJ et al., Mol Cell JNCASR, Bangalore in 1997. Ranga has EXPRESSION. population 2006, PMID: been working with HIV for the past 25 years. He is a member of the Trainee arises due to 17189188). Selection Panel, AIDS International differences encoded at the genetic Likewise, noise in λ-phage Training and Research Program of the Albert Einstein School of Medicine, New level. However, phenotypic variability regulatory circuit, under York. He is also a member of various is observed even in a cell population fluctuating host environment, other National and International with identical genetic content under a influences switch between two societies such as the American Society of Microbiologists, International AIDS homogenous environment. This non- developmental fates: lytic cycle Society, National Immunology Society genetic variability among an isogenic and lysogeny (Arkin A et al., and Molecular Immunology forum. He can be reached at population is a result of random Genetics 1998, PMID: 9691025). [email protected] fluctuations in gene expression or gene Following the integration leaving the virus in a transcriptionally expression ‘noise’ (Raj A et al., Cell of HIV-1 into the host genome, the silent state - an ultimate obstacle 2008, PMID: 18957198). provirus must choose between two towards a ‘functional cure’. The switch Noise in a cell population arises due to mutually exclusive infection fates: between these two infection fates of fluctuation in biochemical processes active replication, leading to successful the virus is controlled by Tat, the such as transcription, translation, virus production, or proviral latency,

DRISHTI [Issue 1, Q3, June 2020]

18 Sreshtha Pal, Vijeta Jaiswal, Udaykumar Ranga* master regulator of transcription that transcriptional dynamics of each cell at and followed using an automated time- establishes a positive-feedback loop, the population level. With the advent lapse live-cell confocal microscope for and a multitude of host and epigenetic of single-cell molecular imaging 15-18 h. Images are captured in factors. HIV-1 promoter is inherently techniques, determining the number of multiple plains at an interval of 10 noisy as compared to any other mRNA/proteins in a cell and variation minutes for multiple fields. As shown cellular promoters. The inherent noise among the population has become in the figure, the single-cell trajectories of the viral promoter is subsequently straightforward. The variability in a are extracted from the acquired amplified many folds by the population, an estimate of gene images after background subtraction, downstream Tat positive-feedback expression noise, is calculated in terms and the coefficient of variation is loop; thus, greatly influencing the of coefficient of variance (CV), the ratio calculated. active versus latent decision making. of the standard deviation to mean of However, one of the limitations of The bursty nature of viral the population (see Figure-1 next this study is the use of d2EGFP, which transcription is due to competitive page). has a half-life that does not mimic binding of activators, repressors, and To determine noise in HIV-1 gene transcript half-life. Further, d2EGFP is chromatin remodelers to the multiple expression, we employ a sub-genomic typically measured in arbitrary transcription factor binding sites HIV-1 lentiviral vector that co- fluorescence units rather than occurring in tandem and close expresses a destabilized green molecular units that prevent the proximity in the viral promoter. fluorescent protein (d2EGFP) and Tat quantitative estimation of molecules. A Additionally, HIV-1 exhibits a high under the control of HIV-1 LTR, the more direct approach for studying degree of genetic variability due to its promoter of the virus. The activity of stochastic gene expression would be high replication rate. Any mutation at the promoter is determined by the quantification of transcripts across the key regulatory element leads to monitoring the expression levels of the different cells in a population. This can modulation of transcriptional short-living d2EGFP (a half-life of be performed using single-molecule dynamics (transcription burst size and approximately 2 h). Jurkat T-cells are fluorescence in-situ hybridization (sm- frequency), thereby influencing infected with the reporter lentiviral FISH). Furthermore, transcriptional latency decisions. vector at ~0.1 MOI to ensure a single dynamics can be evaluated using MS2- How do we study noise in HIV-1 integration event of the virus per cell. tagging technique, where mRNA gene expression? Until recently, The infected cells are sorted by flow dynamics can be followed in the scientists studied gene expression only cytometry to generate a clonal cell context of a live-cell. The application of at the level of the population - a population. Different clonal cell molecular imaging techniques at the strategy limited by averaging the populations are activated with a single-cell level has become heterogeneity among individual cells. cocktail of mitogens after immobilizing instrumental in evaluating stochastic It was not possible to examine the them on a glass-bottom micro-slide gene expression.

Turn to page number 46 to read Focus Interview by Dr. MKC

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19 Sreshtha Pal, Vijeta Jaiswal, Udaykumar Ranga*

Figure-1: (a) Time-lapse live-cell confocal microscopy snapshots of HIV-1 infected Jurkat T-cells at different time points. (b)Time-lapse d2EGFP trajectories of individual HIV-1 infected cells. A plot of raw d2EGFP trajectories (promoter activity) versus time obtained after background subtraction of a time-lapse confocal microscopy movie of HIV-1 infected cells imaged for 18 hours. Each trajectory represents an individual cell. Variability in the population was determined by calculating the coefficient of variance (CV).

Multi-photon Laser Scanning Microscope – Page number 48

Opinion – Dr. Deepak - Page number 53

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20 PERSPECTIVE: COVID-19- A WAKE-UP CALL FOR INFECTIOUS DISEASES IMAGING

Dr. Gayatri Gowrishankar

Multimodality Molecular Imaging Lab, Stanford University, USA

Since the discovery of summarized the years of research [18F]Fluorodeoxyglucose (FDG) in and investment that has gone into 1976, radiopharmaceuticals and developing PET tracers for positron emission tomography oncology in contrast to the (PET/CT) imaging has played an investment in infectious diseases important role in the clinical [2]. As was pointed out in this management of oncology patients. The article, the Molecular Imaging and Dr. Gowrishankar received her power of PET includes the ability to Contrast agent database (MICAD) Bachelor of Science Degree in Zoology follow physiological processes like lists as many as 5359 PET tracers from Stella Maris College, Chennai, India in 1996 followed by a Master of glucose metabolism in the whole body that have been developed for Science in Biotechnology from Madurai with exquisite sensitivity (10-12M) and Oncology as opposed to just 13 Kamaraj University, India in 1999. She was awarded three gold medals for high spatial resolution (~5mm half PET tracers for Infectious being the most outstanding student. width at half maximum) [1]. Moreover, Diseases. However as we have seen She then earned a Ph.D. in Biochemistry in contrast to single photon emission with the COVID 19 pandemic, the from the University of Hannover, Germany. Dr. Gowrishankar joined the computed tomography (SPECT) burden from infectious diseases Molecular Imaging Program at Stanford imaging, PET has University in 2005 as a postdoctoral fellow in the lab of Professor Jianghong imaging offers IMAGING CAN PLAY A enormous Rao and remained at Stanford as a dynamic, POWERFUL ROLE IN THE ramifications Research Scientist in the Multimodality quantitative data and we need Molecular Imaging laboratory under CLINICAL MANAGEMENT the mentorship of Professor Sanjiv Sam sets with which OF PATIENTS SUFFERING to increase Gambhir in the Department of tracer kinetic our Radiology. She has been involved in FROM BACTERIAL OR various research projects involving the modeling can be investment VIRAL INFECTIONS. development of PET tracers for done. The into better Oncology and, more recently, in widespread use diagnosing Infectious Diseases. She can be reached at [email protected] of [18F]FDG in oncology, paved the way and managing infectious disease for molecular imaging research and led patients. [11C] –D Alanine, [18F] to the development and clinical Despite the insufficient attention it Fluoromaltotriose and many others in translation of various PET tracers has received, there have been several the pipeline [3]. While all of these including [68Ga] DOTATATE and [68Ga] novel PET tracers that have been newer tracers target different features PSMA. In an elegant perspective developed to image bacterial of bacterial metabolism, other written for Science Translation infections in the last 5 years including, strategies to image bacterial infection Medicine in 2019, Ordonez et al [18F] Fluorodeoxy-sorbitol, [11C] PABA, include the use of radiolabeled

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21 Dr. Gayatri Gowrishankar antibiotics like [18F]Fluoropropyl malDFO-169, [64Cu] Ox40 and many In conclusion, COVID 19 has trimethoprim, [11C]Rifampicin, others [4]. reinforced what infectious disease [76Br]Bedaquiline or to image the There are additional physicians and the Gates Foundation immune microenvironment using considerations that must be taken into have been saying for years: ‘infectious well-established tracers like [18F]FDG account while investing in the diseases are here to stay’. As a society or [18F] DPA-714 [3]. All of these development of PET tracers for we need to be prepared to face the next tracers in the pipeline are targeting infectious diseases. Unlike oncology, in crisis. Imaging can play a powerful role bacterial pathogens. There have been infectious diseases the PET tracers in the clinical management of patients far fewer efforts to develop agents might not play a role in the initial suffering from bacterial or viral targeting fungal, viral and parasitic diagnosis of a bacterial infection. This infections. The last decade has seen the pathogens. COVID 19 will change this is usually done in an outpatient setting pre-clinical development of a and we are now seeing a renewed and is heavily dependent on emerging multitude of PET tracers that could be interest in developing new ways to point of care diagnostics. In addition, used to image both bacterial and viral image viral infections. The same determining the exact identity of the infection. The forthcoming decade will strategies applied to imaging bacterial pathogen is crucial in the management see the gradual clinical translation of infection can be applied to other of patients with infections. This can these tracers. This is where countries pathogens i.e., a) develop pathogen usually be done by PCR or sequencing like India could play a very important specific tracers, b) target immune based approaches. The infectious role by collaborating and participating environment and c) radiolabel disease specific PET tracers will play a in the clinical trials. Due to the higher therapeutics targeting specific role in the hospital setting where it is prevalence of infectious diseases in pathogens. Imaging the immune crucial to confirm that a patient with a India, Indian physicians and scientists microenvironment can be particularly suspected bacterial infection truly has have gained a wealth of knowledge and important for viruses. T cell driven a bacterial infection, to localize the site have much to offer to the scientific immune responses drive viral of infection, to determine the extent of community as a whole. pathogenesis. Hence, tracers that the infection and to monitor the References: target T cell markers can be used to response to treatment (Figure 1). The 1. James, M.L. and S.S. Gambhir, A molecular imaging primer: modalities, track viral load and monitor anti- viral last point is truly the most important imaging agents, and applications. Physiol treatment. There are a whole host of as in many clinical indications like Rev, 2012. 92(2): p. 897-965. 2. Ordonez, A.A., et al., Molecular imaging tracers that are being developed by tuberculosis, osteomyelitis or of bacterial infections: Overcoming the multiple investigators to image T cells endocarditis, patients are put on barriers to clinical translation. Sci Transl Med, 2019. 11(508). including small molecule based like prolonged courses of antibiotic 3. Mota, F., et al., Radiotracer Development for Bacterial Imaging. J [18F] Ara G, [18F] CFA and treatment with the clinicians unable to Med Chem, 2020. 63(5): p. 1964-1977. antibody/protein based like [89 Zr] determine if the patient is responding 4. Wei, W., et al., Noninvasive PET Imaging of T cells. Trends Cancer, 2018. to the treatment or not. 4(5): p. 359-373.

Up Next: Radiology of COVID-19: The basics

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22 Dr. Gayatri Gowrishankar

Blood/Tissue Whole Body Imaging culture (PET/CT, MRI, PET/MRI) Imaging Emerging point of care diagnostics

Blood/Tissue Whole Body Imaging culture (PET/CT, MRI, PET/MRI) Imaging Emerging point of care diagnostics

Figure-1: Schematic representation of the role of PET/CT imaging in the diagnosis and monitoring of patients with infectious diseases.

DRISHTI [Issue 1, Q3, June 2020]

23 RADIOLOGY OF COVID-19: THE BASICS

Ronald L Korn MD PhD

Chief Medical Officer of Imaging Endpoints Research and Core Lab Medical Director of Virginia G Piper Cancer Center at HonorHealth, Scottsdale, Arizona, USA

The ongoing SARS-CoV2 (COVID- viral pandemic. One of the factors 19) viral pandemic has led to an for controlling the spread of this awareness of just how vulnerable the highly contagious virus is through world’s population is to contagious adequate testing to find out who is diseases. At the time of this writing, actively infected (through RT-PCR over 8 million people have been nasal swab testing), who has been stricken with the SARS-CoV2 virus exposed and who has recovered Dr. Korn completed a Doctor of which is the cause of the COVID-19 (through antibody blood testing) so Philosophy degree in Molecular Biology infection. While most people who have that appropriate actions can be at Albert Einstein College of Medicine, the virus are asymptomatic or exhibit taken. However, as the detection of followed by his Medical training at Stanford School of Medicine. He had only mild symptoms, those who have the disease has been hampered by his postgraduate training at the pre-existing the limited Hospital of the University of Pennsylvania. Dr. Korn specializes in conditions PATIENTS WITH COVID- number and Nuclear Medicine and Cancer Biology

(diabetes, 19 INFECTIONS HAVE A distribution with extensive involvement in clinical hypertension, of testing kits, research. Dr. Korn has received public VARIETY OF SYMPTOMS recognition and awards from the obesity, many American Society of Clinical AND CLINICAL elderly) are at institutions Oncology, American College of Radiology Imaging Network, Ibis most risk for CONDITIONS THAT CAN are turning to Foundation of Arizona, and received developing the BE DETECTED AND THEN the use of the Top Doctor Award for Radiology most severe FOLLOWED BY IMAGING. imaging and Nuclear Medicine. Though his professional accolades accurately effects of the (chest X-Rays, reflect his clinical excellence, his disease (e.g. acute respiratory distress CT scans and Ultrasound of the current professional associations, education-based activities, and syndrome, renal and cardiac failure, Chest) to look for the tall-tale signs commitment to clinical research neurologic and vascular disease) and of the disease, particularly in those quality make up the core of this death. Although there is still much to with moderate to severe professional. He also is an Adjunct Faculty at The Translational Genomics learn about the biology of the virus and symptoms. This article briefly Research Institute, City of Hope, how to cure and/or prevent the describes the common imaging Scottsdale, Arizona. He can be reached at disease through better treatments and findings in patients with COVID-19 [email protected] vaccine development, there is an ever- with special focus on lung imaging review of the radiology of COVID increasing number of peer-reviewed as it is the most common organ of (https://www.rsna.org/covid-19). publications, reports and descriptions radiographic change. The reader is In order to understand the imaging from “boots on the ground” that directed to the online RSNA learning findings due to COVID-19, it is provide a comprehensive view of the center for a more comprehensive

DRISHTI [Issue 1, Q3, June 2020]

24 Ronald L Korn MD PhD important to recognize how the SARS- are seen on Chest CT (Figure 1). These performance the use of CT scans as a CoV2 virus infects different parts of the changes include: screening tool is strongly discourage body. It is believed that the virus • Rounded Ground-glass because of the high false positive and enters into healthy cells through the opacities (GGOs) false negative rates in an unselected ACE2 receptor. The ACE2 receptor is • Consolidation population. Nevertheless, CT scans can found in various tissues throughout • Intra and interlobular septal provide critical information to help the body including the nasal passages, thickening (IST) manage a patient’s condition, lungs, heart, kidney, intestines, brain, • Subpleural clearing (SPC) especially during hospitalization. blood vessels and certain immune cells • Air Bronchograms The logistics of performing CT required to fight off the disease. The • Vascular congestion chest exams can be challenging, distribution of the ACE2 receptors in • Septal banding especially in the critically ill patient our body provide a reasonable • Diffuse Alveolar Damage who has to be moved from the ICU explanation for the symptoms seen in These findings are usually bilateral ward, through the hospital corridors people infected with the virus- from and begin mainly in the posterior and into the CT scanner suite. This nasal congestion and loss of taste and segments of the lower lung lobes operation requires special care as the smell, cough, heart attacks, renal following a pattern of involvement that mere transport and scanning of the failure, strokes, encephalitis, blood is seen in patients with food or fluid patient can lend itself to increased clots and end organ failure. A closer aspiration. This has led to the COVID-19 exposure of healthcare staff, look at the concentration of ACE2 hypothesis of the virus entering the technologists and others. Special care receptors in the airways show that the lung through aspiration of nasal is also required to ensure that personal highest concentration is found in the secretions and/or acid reflux (a protective equipment is readily nasal passages with decreasing condition seen more commonly in the available and worn by those directly concentrations noted as you travel elderly and obese). Although the CT involved in this process and that distally into the lungs. In the lungs the chest findings above are typical for special procedures are in place to clean ACE2 receptors are primarily found on COVID-19 they are by no means areas of patient contact. In hospitals Type II Pneumocytes which are the specific. They can be seen in other viral with limited resources this could place cells primarily responsible for infections (SARS, MERS, Influenza) and additional burdens on staff to maintain maintaining patency of the alveoli to other non-infectious processes that a safe environment. All of these factors allow for adequate exchange of O2 and damage the lungs (e.g. inhalation have led to reduced access to CT. In CO2 through the production of injury, trauma, drug reactions). lieu of these factors, the use of Chest X- surfactant- a molecule that reduces the Therefore, the diagnosis of COVID-19 Rays (CXR) has been advocated in surface tension of pulmonary fluids based upon CT needs to be made in the patients with suspected or known and contributes to the elastic context of the patient’s clinical COVID-19 infections. One of the properties of the lungs. As a result of presentation, risk factors, exposure advantages of CXRs is that it can be the either direct viral infection of these history with other COVID-19 infected done at the patient’s bedside and cells and/or damage from the patients and prevalence of the disease dedicated COVID-19 CXR machines can resultant inflammatory response in the community. Thus, in the be assigned. The drawback, however, directed by the immune system appropriate setting, the sensitivity and is that the sensitivity and specificity for (cytokine release storm) the Type II specificity of the CT finding can be detecting COVID-19 infections and Pneumocytes undergo destruction quite good (70-90% ranges). However, complications is much lower than CT that leads to the common changes that even with such a decent CT diagnostic (ranges 20-60%). Nevertheless, CXRs DRISHTI [Issue 1, Q3, June 2020]

25 Ronald L Korn MD PhD can provide a rapid picture of COVID- be performed judiciously and to infection shows bilateral, rounded, 19 related infiltrates and helps to rule address clinical questions that help peripheral based Ground Glass out complications associated with better manage a patient. Other Opacities (GGO) with or without ventilation support. Another techniques, such as CXR and US can be consolidation (C), Inter and radiologic test at the bedside that is useful as providing point of care intralobular septal thickening (IST) gaining support is the use of service without complicated logistics and subpleural clearing (SPC). These Ultrasound (US). US uses non-ionizing required to transport the patient for features are compatible with an radiation in the form of soundwaves as CT scans. Finally, the use of AI and organizing pneumonia. Upon healing, it interrogates the involvement of the Radiomics- which uses high resolution there can be resorption of GGO + C lung fields that lie close to the body features on CT scan to better predict with septal band formation. Additional surface. This point of care exam shows the biology, response and need for features of COVID-19 CT include abnormal acoustic shadowing which ventilatory support is being actively vascular engorgement, diffuse alveolar can be followed up over time as the pursued in our laboratory as well as damage, air bronchograms and crazy patient either heals or progresses in others to better predict a patient’s paving patterns. Pleural effusions, their clinical course. It can also be used outcomes and return to full functional adenopathy and other features are with special vascular contrast agents capacity. Although, a modern-day rare. CXR findings can include vague to rule out pulmonary embolism. challenge, perhaps some good news peripheral infiltrates (circles) that are In summary, patients with COVID- regarding COVID-19 is beginning to often bilateral and peripheral 19 infections have a variety of emerge. involving the lower lobes. Bedside symptoms and clinical conditions that Panel of COVID-19 Images Showing Lung US can show so-called scattered can be detected and then followed by Common Features on CT, CXR and B lines due and peripheral imaging. Although CT scans can detect US: consolidation. early changes in the course of the The figure below demonstrates the disease (prior to nasal swap and blood multiple presentation of COVID-19 tests turning positive) its use should Lung Disease during imaging. Early

DRISHTI [Issue 1, Q3, June 2020]

26 ROLE OF ARTIFICIAL INTELLIGENCE IN INFECTIOUS DISEASES

Dr. R Elakkiya

School of Computing, SASTRA Deemed University, Thanjavur, India

Infectious Diseases and AI Though Coronavirus or COVID- As far as infectious diseases 19 trends the newscast, these kind are considered, prevention, of infectious diseases or outbreaks monitoring, rapid-response and aren’t something new for the management efforts to be particularly humanity and it has faced several helpful in decelerating or filibustering throughout history. In recent years, outbreaks. Infectious diseases are very infectious diseases are more Dr. R. Elakkiya is currently working as challenging to diagnose in the early accountable with high percentile in Assistant Professor in Department of stage, with excessive failure rate healthcare expenditures, Computer Science & Engineering, School of Computing, SASTRA resulting in high fatality and alarming appreciably impacting the health of University, Thanjavur. She has 8 years of rate of drug resistance. individuals and societal extensive research experience in the field of Artificial Intelligence & Machine Artificial communities. Learning and she is very much Intelligence (AI) Before COVID- passionate towards the recognition of and Machine 19, three major Sign Languages of different countries. Apart from Sign Language Learning (ML) now outbreaks were Recognition, remarkable contributions becomes a new documented: has been made in the field of medical image processing in early diagnostics strategic weapon Ebola(2014- of cervical cancer using colposcopy in the global health 2016) reported images, epilepsy seizure prediction care system is now 28,646 cases, using EEG signals and COVID-19 using Chest Xrays and CT Scan images. Her emerging to assist SARS(2002- research specifically focusses on with infectious 2004) reported addressing the trending issues and disease prevention, rapid-response, with 8098 cases and MERS(2012) huge need for ML & DL, by filling a gap within a multidisciplinary field to surveillance and management. One of reported with 2494 cases. Based on include computer science, the most thrives of AI is often seen in the documentation of parasitic mathematics, engineering, and alike application domains. She is presently life-threatening and time-sensitive infectious diseases over 3.9 million the Editorial Board Member in conditions. In most of these kind of hospital outpatient-department got Information Engineering and Applied critical situations, AI can help us better visited in 2011 and in 2014, for the Computing Journal and reviewer to many top tier journals. She can be diagnose problems easily and quickly same reason over 17.8 million reached at [email protected] so that we can make decisions easily people visited physicians in their Tuberculosis(9,421 cases), and act quickly. respective offices. In 2014, many other Salmonella cases (51,455 cases), Lyme Impact of AI in Infectious Diseases illness were documented with new disease (33,461 cases) and cases which includes meningococcal disease (433 cases)1. DRISHTI [Issue 1, Q3, June 2020]

27 Dr. R Elakkiya

Researchers now started to use AI accompanying the human factor and symptoms of fever and they have to pinpoint the environmental and recent trends in technologies at its deployed the face and temperature epidemiological issues that paves way fullest and best. detection software in China’s for epidemics and to predict the AI & COVID 19-The World Pandemic sophisticated surveillance system. infectious disease outbreaks earlier Coronavirus or COVID-19 which Radio-Imaging departments in before they materialize. A team of US was first identified in Wuhan, China is healthcare conveniences are being researchers from USC Viterbi School of now a world pandemic. On 10th June charged with the amplified load Engineering developed an AI 2020, World Health Organization created by the virus. AI-powered algorithm to help decision makers to (WHO) declared COVID-19 has its diagnostic tool using chest xrays was cut down the overall community spread over developed by AI HAS ITS VAST transmission of tuberculosis (TB), 216 countries various ABILITY TO RAPIDLY malaria and gonorrhea diseases. or territories researchers across Based on simulation results from or areas and TRACK, DIAGNOSE AND different the computers, the researchers so far the MANAGE VARIOUS institutions in validated their algorithm on two real- deadly virus INFECTIOUS DISEASES IN India[2,3] to reduce time diseases: TB data from India and infected more REAL TIME. the burden of RT- gonorrhea data from United States. than 71.4 PCR test. Alibaba, From the results, they inferred that the million people Chinese e- algorithm did a superior work in and has claimed more than 4 million commerce organization built reducing disease cases by sharing the lives globally. a diagnostic tool using CT scan images needful information about these The better we trace, the better we and their claim states 96% accuracy in diseases with individuals who are at fight against this highly contagious diagnosing the virus in seconds. risk. disease. AI paves it’s way here to learn Another researcher from IIT- Microsoft, and detect an outbreak Hyderabad[4] developed a test kit costs using AI are of COVID-19. Blue Dot, a only ₹600 per test which is 10% of partnering with Canadian health actual cost of RT-PCR test. The test kit Adaptive monitoring platform is powered by AI technology which Biotechnologies raise the first alarm would give the results in just 20 to assist in the about the novel minutes thereby it can break the bioinformatics coronavirus infections another barrier in diagnosing the analysis of DNA to the world. BlueDot’s infectious diseases. sequencing by AI forecasted the To understand the protein decoding the T-cell and B-cell prediction of spread and warned about structure of COVID-19 virus, Google’s receptors to assess the human immune the issue and risk several days before Deep Mind5 division used AI and its system. The utmost objective of their the public warnings released by advanced computing power to help analysis is to create a universal blood Centers for Disease Control and others develop treatments for the test to detect variety of diseases Prevention and World Health cause. BenevolentAI uses AI to build including infectious diseases in very Organization. SenseTime used AI drugs to treat coronavirus. AI based early stage of transmission by reading technology for face recognition to Chatbots in Whatsapp, MyGov Corona the person’s immune system. This identify the people and detect their helpdesk launched by Ministry of epitomises the power of AI for body temperature to check for the

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28 Dr. R Elakkiya

Health, Image Source5: Google’s researchers, start- 2. https://timesofindia.indiatimes.co DeepMind Protein Structure m/city/chennai/tamil-nadu- Government Analysis ups, organizations of India have and governments to university-develops-ai-based- been useful in prevent or better software-for-covid-19- creating the reduce the harm preliminary- awareness and disruption of screening/articleshow/76088643. cms about the infectious 3. https://timesofindia.indiatimes.co infectious diseases. AI has its m/india/indian-scientists-devise- disease and vast ability to low cost-ai-based-software-to- communicating the essential rapidly track, diagnose and manage detect-covid- information to the people and can various infectious diseases in real 19/articleshow/75187192.cms make the people getting free online time. AI not only will assist in 4. https://www.thehindubusinesslin health consultation services through it. developing better algorithms or e.com/news/science/iit-h- Government of India launched Arogya models for tracking the transmission, develops-ai-based-covid-19-test- Setu, an AI based application for forecasting the spread and diagnosing kit-priced-at- smartphone’s users to provide the the diseases, but might also be 600/article31773056.ece information about novel coronavirus influential in thwarting untimely 5. https://www.zdnet.com/article/g infection using GPS system and deceases. oogle-deepminds-effort-on-covid- Bluetooth technology that will help References 19-coronavirus-rests-on-the- user to know how far they are from the 1. Engelkirk PG, Duben-Engelkirk J, shoulders-of-giants/ infected person. Fader RC. Burton's microbiology The extended use of AI and for the health sciences. Jones & machine learning has enabled Bartlett Publishers; 2020 May 21.

Image Source2: Chest X-ray Classification

DRISHTI [Issue 1, Q3, June 2020]

29 MRI FOR IMAGING INFECTIOUS DISEASES

Dr. Sudheer Kunkunuru, MBBS, MD(RD), EDiR

Fellow in Diagnostic Neuroradiology, Co-Founder & CEO VaidhyaMegha Pvt Ltd.

Of all the imaging modalities shift in the utilization of MRI currently available for clinical capabilities from just being a tool of diagnostic needs and research anatomical imaging to evaluation Magnetic resonance physiological imaging by assessing imaging (MRI) holds a very special role the response of body to injection of in being highly accurate and drugs or contrast agent, to anatomically precise in its capabilities. functional imaging of body like in MRI uses the inherent magnetic thinking processes or beating heart Dr. Sudheer specializes in neuroradiology, musculoskeletal, properties of the abundantly available or CSF flow or bowel movement abdominal and soft tissue imaging. hydrogen proton in the human body at assessment or kinematic imaging of He completed his MBBS and MD from Mahatma Gandhi Institute of all anatomical levels and hence is joints, to the latest Molecular Medical Sciences (MGIMS), radiation free imaging by Sevagram, Wardha, Maharashtra. He which has non-invasively trained in Intervention Radiology at THE ROLE OF MRI IN the Army Hospital Research and been in many assessing Referral, New Delhi. He served as a THE EVALUATION OF instances the cellular and consultant at Vijaya Diagnostic Centre and Apollo Hospital in shortcoming INFECTION WAS MORE OF molecular Hyderabad. He is also an Associate of other A CONTRIBUTORY ROLE processes Professor at Prathima Institute of radiological IN PREDICTING A through Medical Sciences, Karimnagar, Telangana, India. Sudheer also has a imaging POSSIBILITY RATHER convergence of fellowship in Diagnostic neuroradiology as well as the techniques. THAN CONFIRMATORY engineering, European Diploma in Radiology. He is The molecular OR COMPLETELY a Diplomate of the Indian College of role of MRI in biology, Radiology & Imaging. He is a DIAGNOSTIC the setting of chemistry, member of the European Society of Radiology, Indian Radiology Imaging brain stroke, immunology, Association, European Society of musculoskeletal imaging, brain and genetics and image analysis. Neuroradiology – Diagnostic and Interventional, and the Indian Society spine imaging, cardiac imaging and Though traditionally of Gastrointestinal & Abdominal neurodegenerative disorder nuclear medicine imaging Radiology. He can be reached at evaluation has become essential and techniques using tracers in 18F FDG- [email protected] pivotal over the past decade without PET or SPECT has been the USG or MRI in the recent years. any competition and is only limited by mainstay in Molecular imaging Molecular MRI imaging contrast the amount of time required for particularly because of low sensitivity agents are usually based on acquiring and interpreting the scans. of MRI contrast agents, there have nanoparticulate probes which contain There has been substantial paradigm been significant developments in the a high payload of contrast generating role of radiation free imaging using materials like iron oxide nanoparticles

DRISHTI [Issue 1, Q3, June 2020]

30 Dr. Sudheer Kunkunuru, MBBS, MD(RD), EDiR or nanoscaffolds loaded with weighted positive contrast imaging interpretation in infective disease gadolinium chelates. using lanthanide chelates like processes like abscess in liver or Gadolinium or non-lanthanide spleen or kidney where it is key to The role of MRI in the paramagnetic Manganese based differentiate infection vs neoplastic evaluation of infection was more of a contrast agents. MRI is also in a nature of lesion. Functional contributory role in predicting a position to determine the time frame parameterization and impairment possibility rather than confirmatory or of the infection process in the body related to infectious diseases are being completely diagnostic, however, with reliable assessment of acute or evaluated in dynamic cardiac MRI unsurpassed information is made chronic status of the disease which has studies. available in defining the exact extent, been in many instances difficult to Recently experimental nature and involvement of anatomical interpret even at intra operative Molecular imaging technologies have structures involved through infective assessment. been used to image invasive disease processes by its excellent MRI is the investigation of pulmonary aspergillosis using inherent in-depth intrinsic soft tissue choice in evaluating cerebral and antibody-guided PET/MRI not just for contrast and higher-level detailed spinal infections at various anatomical cerebral or central nervous system anatomical resolution imaging. It still levels - be it at skull level or brain infections but also for pulmonary has no role or very limited role in coverings or brain fluid - CSF or nerves infections using ultra-short echo times directly or accurately detecting the coming out of brain or within brain (Thornton CR et al., 2018). Recent infectious agent responsible for parenchyma or spinal cord which is studies have also demonstrated the disease and requires very good poorly evaluated by Computed enormous potential of antibody- interpretation skills from dedicated Tomography (CT) or 18F FDG-PET. The guided PET/MRI technologies to experienced radiologists to precisely MR imaging characteristics have been dramatically improve the molecular make a particular infective agent as so overwhelmingly uniform in imaging of viral (Santangelo et al., causative. However, there has been a predicting the causative infective 2014), bacterial (Wieher et al., 2016) substantial improvement in the agent indirectly in certain common and fungal (Rolle et al., 2016, Davies et interpretation skills of radiologists of diseases like tuberculosis, al., 2017) infections in vivo, with the all experiences in characterizing the cysticercosis, toxoplasmosis, real possibility of precision medicine lesions as possible bacterial or fungal cytomegalovirus encephalitis or for infectious diseases in the near or parasitic or viral etiologies in many syphilis, aspergillosis, cryptococcosis future (Jain, 2017). instances. or herpes or HIV that they just need Future promise MRI has made significant in- correlative lab testing or specific The use of roads into the evaluation of chemical targeted culture or simple superparamagnetic iron oxide (SPIO) and pathological composition of the microbiological investigations for nanoparticles with their characteristic infective and non-infective disease validation. Though motion related magnetic susceptibility qualities and processes which has been an imaging artifacts have been a major constraint their ability to be labeled to challenge to-date through various in evaluation of moving structures like macrophages and subsequent MRI advanced and refined techniques like heart and abdomen through MRI, the detection / trackability has been used diffusion imaging / angiography / use of ECG and respiratory gating to evaluate infectious diseases and spectroscopy / arterial spin labelling / techniques have successfully targeted their immune system interactions. perfusion / diffusion tensor imaging / the acquisition only to non-mobile SPIO use T2-weighted imaging with magnetization transfer and T1 phases and led to improved negative contrast and are coated with

DRISHTI [Issue 1, Q3, June 2020]

31 Dr. Sudheer Kunkunuru, MBBS, MD(RD), EDiR dextran (Feridex), starch, polymer background signal. Role of other influenza virus infection (Aramini JM (monodisperse iron oxide Functional MRI approaches, including et al., 2014). nanoparticles-MION) or citrate or spectroscopic imaging of MRI-visible There is a lot of exciting inorganic silicon materials or but less sensitive heteronuclei, such as promise for collaborative imaging polyacrylic acid or dopamine or 31P or 13C is also looked into. using novel MRI imaging techniques, deferoxamine and the recent being Particularly the role of MRI at image high strength MRI imaging, USPIO (Ultrasmall super paramagnetic analysis and drug development, nanoparticle contrast molecular iron oxide) and CLIO (cross linked iron Fusion of dynamic MR & dynamic 18F imaging and immunoPET imaging in oxide). FDG-PET for parametric (PK) maps animal studies relevant not just to While most of the clinical MR and cancer typing is looked into in the infectious diseases but also for cancer imaging uses the water protons 1H to current research protocols. Labelling disease and the scope for subsequent create contrast enhancement, of the influenza A/Udorn/307/1972 validation with approval in human nanoparticle imaging using 19F is being virus (H3N2) with the MRI agent, 5- imaging for better management of used for research purposes due to its fluorotryptophan, demonstrated the human diseases and well-being. high gyromagnetic ratio and low feasibility of using (19F) MRI to directly abundance in the body which results in visualize and quantify the helix-helix absence of undesired tissue ED dimer interface of NS1A protein in

Upcoming Event…..

MISI is organizing a series of webinars every month as part of its activities. The initial webinar is scheduled on July 29th, 2020 between 6 and 7 pm (Indian Standard time). The title of the Webinar is:

“MRI Basics Revisited – Future Directions with Relevance to Molecular Imaging”

The resource person is Dr. Sudheer K who is a noted neuroradiologist.

DRISHTI [Issue 1, Q3, June 2020]

32 PHOTOACOUSTIC MOLECULAR IMAGING OF INFECTIOUS DISEASES

Prof. Sri-Rajsekhar Kothapalli

Department of Biomedical Engineering, Penn State College of Engineering, USA

Significance measurements, and also time Infectious diseases are caused by consuming. For example, it takes up pathogens such as bacteria, viruses, to 2 days to diagnose the Covid-19 fungi and parasites. Among all human disease using a standard SARS-Cov- diseases, infectious diseases cause 2 virus-specific reverse high mortality, morbidity and financial transcriptase polymerase chain Raj is an Assistant Professor burden [1]. It is estimated that by reaction (RT-PCR) test [2]. Serial of Biomedical Engineering at the Penn State College of Engineering. 2050, antimicrobial drug resistant testing is often required to rule out An M.Eng. in Applied Optics from IIT, infections will become the leading the possibility of negative results. Delhi, Raj completed his MS in cause of Medical Applied Physics from University of Massachusetts followed by his Ph.D. mortality NON-IONIZING, NON- imaging in Biomedical Engineering from INVASIVE, PORTABLE, LOW- globally, 10 technologies Washington University. He did his COST, AND REAL-TIME million per year, provide postdoctoral research in Radiology MOLECULAR IMAGING from Stanford University. His lab surpassing the spatial harnesses two fundamental sources TECHNOLOGIES ARE DESIRED number of (whole body of energy, light and sound, to image TO SHIFT THE PARADIGM OF structural, functional and molecular cancer deaths. or organ INFECTIOUS DISEASE information of living subjects. His The current specific) and group develops novel imaging tools DIAGNOSIS AND TREATMENT COVID-19 temporal based on optical, ultrasound, and photoacoustic technologies for pre- pandemic (several clinical and clinical translation exemplifies the need for rapid days) information of the disease applications in neurological, cancer and cardiovascular diseases. These development and testing of cost- progression using non-invasive tools include multi-scale imaging effective diagnostics, various short- approaches. For example, devices and molecular specific term remedies and preventive vaccine. pneumonia (lung infection with approaches to image features as small as organelles and as big as Current technologies and the gap in fluid and pus accumulation) is one organs. He can be reached at the knowledge of the main symptoms of the mid- [email protected]

In vitro diagnostic methods for phase of the infectious diseases. results. However, for early diagnosis of infectious diseases, although gold Anatomical imaging modalities such as the disease and for developing, testing standard, suffer from disadvantages chest computed tomography (CT) and and translating various treatment such as invasive tissue sampling (e.g., lung ultrasound (LUS) play a key role options through pre-clinical phase, nasal swab or blood) with risk of in serial testing of pneumonia and rule pathogen-specific molecular imaging contamination, static one time-point out the possibility of false negative technologies are required. Molecular

DRISHTI [Issue 1, Q3, June 2020]

33 Prof. Sri-Rajsekhar Kothapalli imaging can help delineate the images of deep tissue with high allowed unrivaled pre-clinical PAI inflammation from infection, identify ultrasonic spatial resolution [5]. In applications in cancer (tumor infectious pathogen, and follow the PAI, pulsed photoexcitation of the angiogenesis and hypoxia pathogenesis in real-time. Positron tissue and subsequent thermoelastic measurements), cardiovascular emission tomography (PET) is the expansion of light absorbing (thrombosis and plaque lipids) and most sensitive whole-body molecular chromophores (e.g., oxyhemoglobin, neuroscience (cerebral blood flow and imaging technology widely used in deoxyhemoglobin, melanin, and lipids) oxygen saturation). Label-free several pre-clinical and clinical leads to broadband ultrasound wave vascular imaging capabilities of PAI applications of cancer and generation. This photoacoustic effect were also demonstrated in clinical neurological diseases. Recently, the is analogous to the thunder caused by applications such as breast potential of radioactive PET tracers for lightening. For molecular mapping, angiography [6], Crohn’s disease [7], imaging infectious diseases caused by spectroscopic PAI uses multi- and more recently transrectal prostate bacteria, fungi and viruses have been wavelength tissue excitation to excite imaging [8]. Further, when powered demonstrated in pre-clinical as well as molecules at their resonance peaks in by externally administered pilot clinical studies [3]. Although PET the absorption spectrum. photoacoustic molecular agents, the offers exciting possibilities for Conventional ultrasound detectors sensitivity and specificity of PAI can be studying pathogenesis in pre-clinical placed outside the body detect these further enhanced, and its applications infectious disease models, like CT, it is wavelength specific photoacoustic can be largely extended from tissue not ideal for repeated testing on waves and form high contrast images level to molecular and cellular levels. patients due to the use of ionizing in real-time at ultrasonic resolution. For this purpose, a wide variety of radiation. Moreover, PET imaging Spectral unmixing algorithms are used photoacoustic contrast agents, from needs special access to cyclotrons for to map the distribution of different small molecules to organic and isotope production, preferably molecules inside the tissue. Imaging inorganic nanoparticles, have been isotopes with longer half-life to sustain depth and spatial resolution are both functionalized to target disease remote distance applications, and scalable using ultrasound and optical specific biomarkers. In principle, all experienced radiochemists for parameters; typically, a micron light absorbing fluorescent molecules molecular probe development. resolution at 1 mm depth and a sub- have certain probability to generate Further CT, PET and magnetic mm resolution at 5 cm depth. Over the photoacoustic signal when relaxing to resonance imaging (MRI) are past two decades, PAI has evolved as a the ground state through competing expensive and bulky instruments, and multi-scale imaging technology, non-radiative heat decay. Several hence not suitable for widespread use enabling in vivo imaging from targeting approaches have been in the remote parts of the world [4]. organelles to organs in pre-clinical and reported in pre-clinical PAI Non-ionizing, non-invasive, portable, clinical translation applications. applications using florescent low-cost, and real-time molecular Strong intrinsic optical absorption molecules (e.g., Indocyanine green and imaging technologies are desired to from oxyhemoglobin and IR800-dye) and nanoparticles (gold, shift the paradigm of infectious disease deoxyhemoglobin molecules enabled carbon nanotubes, liposomes). This diagnosis and treatment. label-free PAI of blood vasculature, includes photoacoustic reporter genes Photoacoustic Imaging (PAI) is a associated angiogenesis, oxygen (such as iRFP) [9], antibodies (e.g., hybrid optical-ultrasound technique saturation, and total hemoglobin anti-integrin) [10], enzyme (e.g., that provides optical absorption based concentration (blood volume). This matrix metallopetidases (MMPs) and molecular- and functional- contrast multiparametric vascular information Furin) activatable agents [11-12], and

DRISHTI [Issue 1, Q3, June 2020]

34 Prof. Sri-Rajsekhar Kothapalli

DNA aptamers [13]. Similar to scanners) are limited to imaging Like in the case of PET, different fluorodeoxyglucose (FDG)-PET tracer organs. The advent of micromachined photoacoustic molecular targeting (18F-FDG), a fluorescent glucose ultrasound transducers, miniaturized approaches can be approacemployed analogue, 2-deoxy-2-[N-(7-nitrobenz- optical sources (e.g., laser diodes), to detect infectious pathogens. For 2-oxa-1,3-diazol-4-yl)amino]-D- field-programmable grid array (FPGA) imaging bacterial infections, the key glucopyranose (2-NBDG) is capable of based data acquisition, and deep challenge is that the molecular probe crossing the blood-brain-barrier learning algorithms are helping should have high binding affinity to (BBB) via glucose transport protein further reduce the footprint and the bind and accumulate to bacterial cells GLUT, and was demonstrated to map cost of PAUS scanners [15]. In future, a and should be able to distinguish brain metabolism in mouse models smart integration of these bacterial cells from host mammalian [14]. These pre-clinical studies multidisciplinary technological cells. To overcome this, photoacoustic demonstrate the potential of advances will likely achieve a wearable molecular probes must be capable of photoacoustic molecular imaging for and portable PAUS imaging system targeting multiple binding cites on the targeting infectious pathogens. suitable for diagnosing infectious bacterial cell wall or a metabolic On the other hand, the PAI diseases in remote parts of the world. substrate trapped by the bacteria scanners for both pre-clinical and Potential impact of photoacoustic induced enzyme activity. For example, clinical applications are undergoing molecular imaging for infectious a fluorescent derivative of maltotriose rapid developments. Since ultrasound disease (Cy7-1-maltotriose), which provides and photoacoustic technologies share To reliably image pathogens and both fluorescence and photoacoustic the same ultrasound detection understand the pathogenesis, the contrasts, was demonstrated to detect platform, the state-of-art scanners are imaging technology should be infection, assess infection burden, and capable of simultaneously displaying sensitive to unique pathological determine the efficacy of antibiotic ultrasound based anatomical hallmarks and/or molecular treatment in E. coli-induced myositis information and photoacoustic based biomarkers of the pathogens. Besides and in a clinically relevant S.aureus functional and molecular information diagnosis, prognostic information would infection murine model [16]. of the tissue. This is similar to extracted from the imaging For imaging viruses, which are much combined PET+CT or PET+MRI biomarkers (e.g., pulmonary smaller than bacteria, photoacoustic scanners, where PET provides aspergillosis) may also improve the reporter genes or molecular probes molecular information, CT provides infectious disease treatment and that activate in the presence of virus anatomical information, and MRI management, and therefore also likely induced enzymes may yield better provides soft tissue contrast. In help reduce the health care cost. PAUS results. For example, a luciferase and contrast to these conventional imaging scanners integrated with fluorescent fusion reporter strategy systems, dual-modality photoacoustic anatomical, functional, and molecular for influenza virus was demonstrated and ultrasound (PAUS) scanners are imaging capabilities can play a critical in mouse models. Both portable (integrated into a cart) and role in the three key areas of the bioluminescence and fluorescence are cost-effective in the price range of infectious disease: 1) pathogen- imaging were used to follow the $80,000 to $800,000. While dedicated specific diagnosis, 2) understanding influenza virus as it traffics to the lungs small animal PAUS scanners can image pathogenesis and 3) optimize and cause lung infection. However, whole mouse, clinical PAUS scanners treatment options. both bioluminescence and (developed by integrating PAI 1. Pathogen-specific diagnosis fluorescence imaging cannot provide capabilities to commercial US information about the other infections

DRISHTI [Issue 1, Q3, June 2020]

35 Prof. Sri-Rajsekhar Kothapalli and inflammation caused by the virus. infectious disease. Lung infections can 1. Roth, Gregory A., et al. "Global, regional, and national age-sex- Dual-modality PAUS scanners can not be imaged using ultrasound, specific mortality for 282 causes of only track the influenza virus using the inflammation affecting blood oxygen death in 195 countries and territories, 1980–2017: a above fusion reporter but also can saturation at infectious site can be systematic analysis for the Global image lung infection in the ultrasound measured using photoacoustics, and it Burden of Disease Study 2017." The Lancet 392.10159 (2018): 1736- mode, and local tissue inflammation was also demonstrated that the 1788. 2. Mei, Xueyan, et al. "Artificial using the functional hypoxia immune response in mouse models of intelligence–enabled rapid measurements in photoacoustic mode. bacterial infection can be imaged by diagnosis of patients with COVID- 19." Nature Medicine (2020): 1-5. Emerging literature on PET intravenously injecting T Cells labeled 3. Ordonez, Alvaro A., et al. "Molecular imaging of other virus types, 89Zr- with fluorescent molecules (e.g., NIR- imaging of bacterial infections: Overcoming the barriers to clinical VRC01 antibody targeting HIV and 797-isothiocyyanate) [17]. This study translation." Science translational medicine 11.508 (2019): eaax8251. 64Cu-743 Ab targeting Semian Virus, showed time activity of T-cells 4. Trampuz, A., and Werner Zimmerli. shows that targeting viral envelop gradually decreased at the bacterial "Diagnosis and treatment of infections associated with fracture- proteins using antibodies is an infection site and lymph nodes. fixation devices." Injury 37.2 attractive approach to image viruses. 3. Treatment planning (2006): S59-S66. 5. Wang, LV., and Yao j.K. "A practical Alternatively, enzymatic kinases have PAUS imaging can help identify guide to photoacoustic tomography also be targeted for PET imaging of suitable antimicrobial treatments, in the life sciences." Nature methods 13.8 (2016): 627. viruses, such as Thymide kinase in follow response to treatments, and 6. Wang, Lihong, et al. "Single-impulse panoramic photoacoustic computed HSV-1 virus and protien kinases in help vaccine development. For tomography (sip-pact)." U.S. Patent Cytomegalovirus (CMV), using specific example, it is very important to Application No. 16/464,958. 7. Knieling, F., et al. "Multispectral inhibitors. As in the past, these PET understand different mechanisms of Optoacoustic Tomography for targeting strategies can be adapted to action of a specific vaccine. Assessment of Crohn's Disease Activity." The New England journal develop photoacoustic molecular Photoacoustic imaging markers that of medicine 376.13 (2017): 1292. 8. Kothapalli, SR, et al. "Simultaneous probes capable of detecting different specifically target immune cell subsets transrectal ultrasound and viruses, including coronavirus 2 can help identify the changes due to photoacoustic human prostate imaging." Science translational (SARS-CoV-2). vaccine in the same animal over a medicine 11.507 (2019): eaav2169. 2. Pathogenesis period of time, providing multiple 9. Krumholz, Arie, et al. "Photoacoustic imaging of the near-infrared Beyond diagnosis, PAUS scanners can readouts on a single individual. fluorescent protein iRFP in be used to further understand the In summary, dual-modality PAUS vivo." Photons Plus Ultrasound: Imaging and Sensing 2012. Vol. pathogenesis of infectious diseases in scanners integrated with suitable 8223. International Society for Optics and Photonics, 2012. pre-clinical models by imaging the molecular imaging strategies are 10. Pan, D., et al. "Molecular host immune response and also capable of providing complementary photoacoustic imaging of angiogenesis with integrin-targeted treatment response. Liquid or solid anatomical, functional and pathogen- gold nanobeacons." The FASEB tissue biopsy cannot provide complete specific molecular information. Rapid Journal 25.3 (2011): 875-882. 11. Levi, J., et al. "Molecular information about the spatial and developments in PAUS photoacoustic imaging of follicular thyroid carcinoma." Clinical Cancer temporal heterogeneity of the disease instrumentation, clinically relevant Research 19.6 (2013): 1494-1502. and the disease burden. Small animal contrast agents and molecular probes 12. Dragulescu-Andrasi, Anca, et al. "Activatable oligomerizable imaging PAUS scanners can provide non- offers exciting promise for diagnosing agents for photoacoustic imaging of invasive imaging of deep-seated and treating infectious diseases. furin-like activity in living subjects." Journal of the American infections, inflammation, and immune References: Chemical Society135.30 (2013): responses in mouse models of 11015-11022.Zeng, Leli, et al.

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36 Prof. Sri-Rajsekhar Kothapalli

"Photoacoustic probes for Microscope for Point-of-Care and infections." Nature molecular detection: recent Wearable Applications." IEEE Communications 11.1 (2020): 1-13. advances and Sensors Journal (2019). 17. Zheng, Shuai, et al. "Noninvasive perspectives." Small 14.30 (2018): 15. Vera, Denis Beckford, et al. "First-in- photoacoustic and fluorescent 1800782. human total-body PET imaging of tracking of optical dye labeled T 13. Yao, Junjie, et al. "Noninvasive HIV with 89Zr-VRC01 on the cellular activities of diseased sites at photoacoustic computed EXPLORER." Journal of Nuclear new depth." Journal of tomography of mouse brain Medicine 61. Suppl. 1 (2020): 545- biophotonics 11.9 (2018): metabolism in vivo." Neuroimage64 545. e201800073. (2013): 257-266. 16. Zlitni, Aimen, et al. "Maltotriose- 14. Dangi, Ajay, et al. "Towards a Low- based probes for fluorescence and Cost and Portable Photoacoustic photoacoustic imaging of bacterial

Interesting snippets - Milestones in medical imaging #3 Discovery Year Digital radiography introduced 1978 MRI 1980 3D image processing for diagnosis 1984 PET scanning 1985 Spiral CT, MR angiography 1989 EPI, Open MRI 1993 Artificial Intelligence in image processing Current trend

Upcoming Event…..

MISI is organizing a series of webinars every month as part of its activities. The initial webinar is scheduled on July 29th, 2020 between 6 and 7 pm (Indian Standard time). The title of the Webinar is:

“MRI Basics Revisited – Future Directions with Relevance to Molecular Imaging”

The resource person is Dr. Sudheer K who is a noted neuroradiologist.

DRISHTI [Issue 1, Q3, June 2020]

37 KNOW A TECHNIQUE SERIES

ROLE OF FLUORESCENCE IN-SITU HYBRIDIZATION (FISH) TESTING IN MOLECULAR GENOMICS

Mamatha Chivukula*, MD, FASCP,

Gautam Bulusu. BS

Sutter Health Care, USA Mamatha Chivukula is an MD in pathology and has research Introduction probes and the increasing variety of interests in Breast pathology and cytopathology. She is associated Molecular diagnostic assays are FISH techniques has made it with the Mills-Peninsula Medical rapidly expanding areas providing widespread and diversely applied Center and Sutter Medical Network results with high sensitivity and technology. in San Fransisco, USA. She graduated from Siddhartha Medical College specificity. The newer molecular Methodology and completed her MD from the techniques such as fluorescence in situ FISH assists researchers or Medical College of Wisconsin. She hybridization (FISH) has profoundly clinicians to identify where a received a fellowship in Cytopathology from the Medical changed the field of molecular particular gene is located within College of Wisconsin and on Breast diagnostics. FISH is a test that "maps" the chromosomes. The initial step and GYN Pathology from Magee Womens Hospital. She is certified in the genetic material and can be used to of the FISH technique is to prepare anatomic and clinical pathology. visualize specific genes or portions of short sequences of single-stranded She was the co-chair of the American genes. Due to recent advancements, DNA that match a portion of the Society of Clinical Pathology. She can be reached at this technique has found increased gene the researcher is looking for [email protected] application in many areas, such as called "probes". Following this step, tightly together, these single-stranded cytogenetics, prenatal diagnosis, these probes are labeled by attaching probes will bind to each cancer research & one of many complementary DNA strand. When a diagnostics, gene CGH HAS available probe binds to a chromosome, its loss and/or REVOLUTIONIZED colors of fluorescent tag provides its amplification, MOLECULAR GENOMICS fluorescent localization and interpretation. gene mapping, IN RECENT TIMES, THUS dye. Because Applications and identification DNA is ESTABLISHING A FISH testing is widely utilized in of microbiological composed of POWERFUL TOOL IN oncology, cytogenetic and pathogens. The two PATIENT CARE. microbiology settings, such as breast availability of cancer, hematological, and other different types of complementary strands that bind hereditary cancers. In breast cancer DRISHTI [Issue 1, Q3, June 2020] 38

Mamatha Chivukula*, MD, FASCP, Gautam Bulusu, BS patients the tumor tissue removed stand-alone technique for them well suited for the routine during a biopsy is subjected for FISH investigating abnormalities and application and enabling of clinical testing to check for extra copies of the following-up on patients. This, microbiology laboratories to report HER2 gene. The higher the number of alongside its relatively low expense, important information for patient HER2 gene copies, the more HER2 makes it a very convenient therapy within a short turn around receptors there are on the tumor cells, investigative tool. time (TAT). FISH PNA probes which subsequently stimulate the Among the rapidly developing represent a new generation of growth of breast cancer cells. FISH test alternative techniques, FISH serves as therapy-directing diagnostics. results give information on cancer as a bridging technology between Conclusions either "positive" or "negative" (Figure microscopy and traditional microbial FISH technique has advanced 1 and Figure 2). A "positive" HER2 culture methods in the identification of allowing screening of whole genomes result by FISH method, the tumor more microbial pathogens routinely in through multi-color chromosome likely respond to treatment with laboratories. FISH technique uses probes using comparative genomic trastuzumab (Herceptin), a drug that short fluorescence-labeled DNA or hybridization (CGH) method. This blocks the ability of HER2 receptors to nucleic acid-mimicking peptide probes simple yet effective technique has receive growth signals. Many clinical (PNA probes) to identify microbial revolutionized molecular genomics in trials use cytogenetic and FISH data to organisms. The PNA FISH probes recent times, thus establishing a stratify patients according to specific provide a rapid and accurate diagnosis powerful tool in patient care. risk factors. FISH is often used as a of infectious diseases. This makes

Upcoming Event…..

MISI is organizing a series of webinars every month as part of its activities. The initial webinar is scheduled on July 29th, 2020 between 6 and 7 pm (Indian Standard time). The title of the Webinar is: “MRI Basics Revisited – Future Directions with Relevance to Molecular Imaging”

The resource person is Dr. Sudheer K who is a noted neuroradiologist.

DRISHTI [Issue 1, Q3, June 2020] 39 DR. M. G. RAMAKRISHNA RAJAN [email protected]

Dr. M. G. Ramakrishna Rajan is an outstanding scientist who headed the Radiation Medicine Centre, Bhabha Atomic Research Centre, Government of India till June 2016. He was also a DAE-Raja Ramanna Fellow till December 2019 and a Professor at the Homi Bhabha National Institute. Dr. Rajan completed his Master of Science (Chemistry) from Bangalore in 1975 and trained in BARC Training School in the 21st batch of Chemistry in 1977-1978. He went to do a Diploma in Computer Management in 1982. He obtained his Ph.D. in Applied Biology in 1993 from Mumbai University. He specialized in Medical Cyclotron and PET Radiopharmaceuticals and focused on Radioimmunoassay, Chemiluminescence & Related Methods. Dr. Rajan has extensive experience in development of diagnostic assays for various infectious and non-infectious conditions. He was involved in developing immunoassays in the Department of Chemical Pathology at Guys Hospital, London where he worked on malaria detection. He also worked towards development of free thyroid hormone assays at the Department of Molecular Endocrinology, Middlesex Hospital Medical School, London in 1984 where he worked with Prof. R.P. Ekins He has vast experience in the chemistry of the production of 18FDG, its quality control, aseptic dispensing, etc., during his tenure at Bereich Zyklotron und

Radiopharmazie of the Universitätsklinikum Hamburg-Eppendorf, Germany in 2003.

Dr. Rajan was also the Deputy Chief Executive for BRIT. He has guided personnel in the operation of the Medical Cyclotron for the production of PET-radiopharmaceuticals assisting with installation, commissioning and operation, from 2002 to 2016. From this facility, over 5000 batches of 18F-FDG have been produced during this period under cGMP guidelines and supplied to hospitals in Mumbai and Pune. Other 18F- Radiopharmaceuticals, viz 18FNaF, 18F FMISO, 18F-FLT, 18F-FET were also prepared for diagnosis and research purposes during his tenure. His laboratory has actively carried out testing of thyroid functions for more than 14000 samples a year. He has guided Ph.D. students in the fields of Chemistry and Life sciences. He was a Member of Expert Committee for Indian Pharmacopoeia Commission, New Delhi, and also the Member of various Regulatory Committees in BARC and AERB. He worked as an IAEA Expert for training staff in developing countries and was also an IAEA consultant for several Coordinated Research Programs. He chaired AERB Committee to bring out a guide for Medical Cyclotron Facilities. He has published 62 research articles and book chapters. He is a life-member of MISI and has constantly encouraged all scientific endeavours of MISI. We appreciate his immense contributions to the field of diagnostics and radiopharmaceuticals in India and hope that

he will continue to motivate and inspire youngsters in these domains.

DRISHTI [Issue 1, Q3, June 2020] 40 YOUNG PROFESSIONAL COLUMN IMAGING – A TORCH IN THE DARK

Sakthivel Gandhi, PhD.

Hybrid Materials Laboratory, School of Chemical & Biotechnology, SASTRA Deemed University, Thanjavur, India

Generally, imaging refers to the notable imaging techniques are X- visual reproduction of an object of ray, computer tomography (CT), interest. It is a wonderful technique nuclear medicine scan, magnetic that gives a deep insight to the resonance imaging (MRI) and valuable details. One such technique is ultrasound. the “Photography” where the In the present situation, a newly moments are cherished forever. This emerged virus from the family of Dr. Sakthivel Gandhi word is coined by Sir John Herschel in beta CoV, SARS-CoV-2, has caused completed his Ph.D. from SASTRA Deemed University, Thanjavur, India 1839 an outbreak with research focus on hybrid CORE-SHELL BASED derived since December materials for theranostics applications. He has won the best from Greek UCNPS DEVELOPED 2019. This dissertation award from SASTRA. He where THROUGH AMPHIPHILIC pandemic has had his postdoc training in the ‘Phos’ COATING, LIGAND caused an Department of Basic Science at Changwon National University, means light unimaginable EXCHANGE AND SILICA Republic of Korea. He joined SASTRA and ‘graphe’ situation of as Assistant Professor in December ENCAPSULATION HAVE means lockdown and 2012. He is the reviewer for funding MADE A BREAKTHROUGH agencies, like RSCF (Russian Science either thereby, Foundation). He received the core drawing or IN NANOMEDICINE AND shattering the research grant from Department of Science & Technology. The research writing. BIOIMAGING FIELDS. layman life and goal of Sakthivel Gandhi, group Therefore, it affecting the leader of hybrid materials laboratory means drawing with light. In the entire world economy. The moral is to create an efficient optical and electrochemical diagnostic tool in similar lines, researchers worldwide which have been learnt is that the addition to the development of were engaged to utilize it for medical early detection is the hi-time need materials for PDT, PTT and sensor applications. He can be reached at purpose where, an excellent patient of the day. According to the reports [email protected] compliance with painless and easy submitted by various countries procedures eliminating the associated world-wide, reverse transcriptase RT- professor of radiology at Thomas surgical complications can be made PCR should only be utilized to detect Jefferson University Hospitals in possible. Currently, an array of the virus in the swab sample, collected Philadelphia says, “Sometimes the RT- techniques are available to the ailing from suspected person’s throat. But, PCR test is negative early in the disease community of people. Few of the Paras Lakhani, MD, an associate course, but the chest CT is positive for

DRISHTI [Issue 1, Q3, June 2020]

41 Dr. Sakthivel Gandhi findings that could represent biomedical imaging. Their amicable and absence of surface functional coronavirus infection.” Hence, the features namely the modifiable surface groups, have been overcome by these imaging techniques will be considered functionality, high surface area, above-mentioned surface as the pillars in screening of pandemic superparamagnetic property and the modifications. Especially the silica diseases in near future. tuneable optical properties, make encapsulation provides, biologically On the other inert nature to the UCNPs hand, a study along with tailored surface. published in The modified surface can be Science easily accessed by the concludes that receptors or specific sites of using cryo diseased region, whereas electron the porous nature of silica microscope shell can host drugs or (CryoEM), can photothermal agent or Figure 1: Pictorial representation of treating infected/diseased cells elucidate the photosensitizers within. through PDT/PTT/targeted drug delivery, using UCNPs. structure of Now, the exposure of NIR spike (S) glycoprotein of SARS-CoV-2. helps UCNPs to get excited and SNPs as the potential probes for early It is well known that the structure of upconvert the radiation into visible detection and cure of deadly diseases protein plays a key role in the light. The visible light would either, be such as cancer through MRI, CT, PDT development of vaccines, therapeutic taken to heat-up the region by using (photodynamic therapy) and PTT antibodies, and diagnostics and hence, photothermal agent or to produce ROS (Photothermal therapy). Among the establishing their importance of by using photosensitizers. Overall, the various nanoparticles, rare-earth imaging in the field of diagnosis and tracking would be possible using elements introduced upconversion therapy. UCNPs through two different ways nanoparticles (UCNPs) have been In addition to the imaging namely, optical and magnetic. The gaining lot of attention in multimodal techniques, the associated materials higher penetration of NIR can easily imaging area due to their ability to such as contrast agents, photodynamic reach UCNPs inside the body and it can convert the lower energy near infra- agents and photothermal agents, play be successfully utilized under in-vivo red light to higher energy visible light. an important role, as if the work done condition. Additionally, the presence In addition to optical and magnetic by the machine and the associated of magnetic Gd3+ based substances in imaging which are used for diagnosis materials are equally shared. At times, UCNPs can be tapped for imaging purpose, UCNPs are actively more efficiency is possible only in the under MRI. incorporated to treat diseases such as presence of associated materials. After Apart from therapy, other areas of cancer through PDT and PTT. the invention of scanning tunnelling research drawing attention of Core-shell based UCNPs developed microscope (STM), the development of researchers, are two hot topics namely through amphiphilic coating, ligand new class of synthetic nanoparticles multimodal imaging and diagnosis. exchange and silica encapsulation (SNPs) have been initiated in large These topics not only boost up the have made a breakthrough in scale. SNPs, whose size ranges career of researchers but, also to come nanomedicine and bioimaging fields. between 1 and 100 nm, are emerging out with a reliable product beneficial The limitations of blank UCNPs such as as multipurpose tools in biomedical for the society. Among the various toxicity, aggregation, hydrophobicity applications, and specifically in nanomaterials, once again core-shell

DRISHTI [Issue 1, Q3, June 2020]

42 Dr. Sakthivel Gandhi based UCNPs are highly sorted owing system that utilizes UCNPs, has drawn “Imaging, in general, relies on to their versatility a considerable optimization to arrive at solutions that in diagnosis and TEM image of silica capped insight. The kit simultaneously satisfy physical UCNPs imaging solutions made using anti- constraints, which are the laws of light for several body and aptamer propagation and scattering from ailments viz., along with NIR light matter, and prior knowledge, which different types of would suffice for the are the types of objects and object cancers, viral and early detection of shapes that are likely to be bacterial diseases. disease. This is encountered in any particular This can be really a booming situation”. Although, the term imaging attributed to their technology right is used in several fields, it sounds inherent optical behaviour. The now in biomedical field. invaluable in science because most of current pandemic situation has To conclude, imaging is a simple the scientific inventions came to light necessitated the development of a object detection method that is built on after the establishment of the imaging ‘point of care’ based on-spot detection the basic principles of light which gives techniques. Thus, the enormous power of disease. Because the isolation of an enormous information and hence, it of the imaging technique has well- diseased, can avoid the social spread is considered as an active area of paved the way for many breakthrough alone. At present the anti-body and research for several years. According discoveries in the field of biomedical aptamers based lateral flow sensing to George Barbastathis, MIT, USA, imaging science.

Figure 2: and pictorial representation of rapid kit for detecting SARS-CoV-2.

DRISHTI [Issue 1, Q3, June 2020]

43 COVID-19 DIAGNOSIS & TREATMENT: WHERE DO WE STAND?

Prof. Uma Maheswari Krishnan

Dean, School of Arts, Science & Humanities, SASTRA Deemed University, Thanjavur, India

The emergence of a new viral being expensive, the design of an strain in a marketplace in Wuhan, antibody against a virus that China in December 2019 has soon led continues to evolve by mutating to a global pandemic in a matter of frequently resulting in different weeks leaving over 4,50,000 dead and strains, makes it difficult to employ more than 93,00,000 infected as on antibody-based kits as a reliable Uma is a Ph.D. in Chemistry and has post-doctoral experience at UT June 22, 2020. The numbers continue diagnostic tool. The sampling for Southwestern Medical Centre, Dallas, to grow with fears of community RT-PCR is also critical as swabs USA. She works with nanostructures and transmission may be carries out surface modification to tailor their properties for appropriate WE ARE TRAPPED IN A looming large. inadequate if applications in therapy and diagnosis. India, with its COVIDIAN ERA WHERE the viral load Development of stimuli-responsive high density shed is low. intelligent therapeutics and point-of- ONLINE MEETINGS, care devices for diagnosis of clinically of population Sputum MASKED FACES, ISOLATED relevant markers is a major focus of her is only behind samples are research lab. Her group uses in silico, SPACES, ECONOMIC in vitro, 3D spheroids and in vivo studies US, Brazil and better for to establish the efficacy of these Russia in STRAIN, RESOURCE analysis of nanomaterials for the intended terms of CRUNCH, UNCERTAIN the presence application. Understanding molecular mechanisms of these nano- number of TIMES FOR RESEARCH IN of the virus. interventions and assessment of safety infections. TERMS OF MEETING Image and efficacy using a combination of molecular, biochemical, RT-PCR has processing DEADLINES AND FUNDING, electrophysiological, imaging and been the gold techniques spectroscopic techniques, is also a AND MENTAL STRESS, HAVE standard for in component of the group’s research BECOME OUR NEW activities. She has over 200 publications COVID-19 combination in this area. She is currently the testing while NORMAL! with Secretary of MISI. She can be reached at [email protected] few antibody- artificial based kits are also in use for detecting intelligence are being explored as a required to avoid the long and painful the presence of SARS-nCoV2, the mode of diagnosis using radiography, wait for results in isolation. Some causative organism of COVID-19. which has also been elaborated in this interesting attempts such as a mask There are several challenges in the edition of the newsletter. However, that changes color when it comes in to diagnosis of COVID-19 that have been techniques for rapid and reliable contact with the virus has been highlighted by experts. Apart from screening of large populations are

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44 Prof. Uma Maheswari Krishnan reported, but cost and specificity age and individuals with co- promoting mental stress and issues limit their widespread use. morbidities were considered to be at a depression among individuals, which In the context of therapy, anti- greater mortality risk, there have been needs to be addressed. Overall, we are inflammatory drugs like many cases, especially in India, where trapped in a COVIDian era where dexamethasone and anti-virals like individuals below 45 have succumbed online meetings, masked faces, remdesivir and favipiravir are being to COVID-19. Therefore, isolated spaces, economic strain, used to treat infected individuals. The understanding the viral pathology is a resource crunch, uncertain times for usefulness of hydroxychloroquine is key for designing therapeutic as well research in terms of meeting deadlines still mired in controversy. Several as diagnostic strategies. Asymptomatic and funding, and mental stress, have immune boosting formulations are individuals present another new become our new normal! In this being promoted as prophylactic challenge in diagnosing and treatment scenario, it is essential for a knowledge measures though their potential in of this disease. Another dimension network to develop solutions to tide preventing COVID-19 is yet to be that is emerging is the implementation over the current crisis. scientifically validated. While earlier of social distancing and isolation that is

War Against Infections!

Everyday we get exposed to new microbes and our immune system tries to neutralize them. Emerging techniques in science have aided researchers to develop synthetic drugs and vaccines that prove an

important component of the arsenal in the war against infections.

Imaging plays an important role in diagnosing the disease that helps in developing effective therapeutic strategies.

The cover art was designed and drawn by a young researcher Ms. V.S. Kaviarasi, a CSIR funded senior research fellow who uses confocal microscopy extensively to image samples from her research involving development of a theranostic nanosystem for management of cerebral ischemia.

DRISHTI [Issue 1, Q3, June 2020]

45 FOCUS INTERVIEW

This section is devoted to interview with an expert who has contributed significantly to advances in molecular imaging. This quarter, our guest is Dr. Murali Krishna Cherukuri.

DR. MURALI KRISHNA Q: Can you tell us briefly about your early academic journey? CHERUKURI A: I started my research career in the Physics department of IIT

Dr. MKC, a life member of MISI, is a Madras in 1979 after a Masters in Physics. Initially I started my project senior investigator in the Radiation on crystal growth but changed to studies of paramagnetism of Biology Branch at the National transition metal ions such as nickel, copper, vanadium in single Cancer Institute (NCI), USA. He also crystals using Electron Paramagnetic Spectroscopy. Though very basic heads the Biophysical Spectroscopy research, it taught me the fundamentals of magnetic resonance Section. Dr. Krishna obtained his spectroscopy. Ph.D. in physics from the Indian Institute of Technology, Madras, Q: What was your early research centred on? What got you India, in 1984 and joined the NCI interested in free radical processes? the same year. His research interests include studies of free radical A: After I obtained my Ph. D in 1984, I joined as a post-doctoral fellow processes in causing oxidative injury and antioxidant defense. He has also at the National Cancer Institute of the National Institutes of Health, been involved in developing Bethesda Maryland, USA. I was working in the Radiation Oncology functional imaging tools to study Branch which is a clinical branch which also had significant laboratory tumor physiology. He can be research activities. Since radiotherapy involves free radicals in its reached at [email protected] therapeutic action and free radicals are paramagnetic, I was using EPR spectroscopy to study free radical intermediates in various radiolytic, photolytic and even chemotherapeutic drugs. This gave me exposure to tumor physiology and metabolism which helped me ion my later years.

“The efficacy of radiotherapy depends on tumor oxygen status.”

Q: What imaging techniques are you using for free radicals?

A: EPR spectroscopy is the only technique which can image free radicals using magnetic field gradients similar to MRI. However, since the magnetic moment of electron is ~ 660 times stronger than 1H which is used for MRI, at a given radiofrequency(RF), EPR imaging needs 660 times lower magnetic field. For example, if the RF used is 300 MHz, the magnetic field for 1H based MRI is 7 Tesla whereas for EPR at the same frequency, the magnetic field is 10 milliTesla. So the cost of EPR Imaging is significantly lower than that for MRI since magnets are easily manufactured at these fields. However since MRI uses 1H from tissue water protons, no exogenous probes are needed. However for EPR imaging exogenous paramagnetic probes which are free radicals with simple spectra are needed. Recently available trityl radical probes with simple spectra and negligible toxicity at the doses needed for in vivo imaging, EPR imaging has become practical.

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46 Oxygen molecule is paramagnetic with two unpaired electrons and can serve as a T2 contrast agent on the trityl radicals. Quantifying this contrast allows EPR imaging to map the tissue distribution of the trityl radical and monitoring the T2 contrast of tissue oxygen on the trityl radical allows mapping tissue oxygen.

Q: When do you think they can be used in clinical practice?

A: The efficacy of radiotherapy depends on tumor oxygen status. If the tumor has low oxygen levels, higher doses of radiation need to be used to treat effectively. EPR imaging is the only imaging method capable of generating quantitative maps of tumor oxygen. With this information, it is possible to develop radiation treatment planning to deliver appropriate doses. The trityl radical used for in vivo EPR imaging in pre-clinical research on experimental animals shows the promise of this technique. This molecule has already been used in humans at 25-50 times lower than used in animals in 13C MRI using hyperpolarized tracers to study tumor metabolism. If the sensitivity of detection can be improved it is a practical and inexpensive clinical imaging modality to study tumor physiology and tailor appropriate treatments.

Q: What are their advantages over current cancer imaging methods?

A: EPR Imaging provides quantitative maps of tissue oxygen. This is the unique feature of the method. This can be integrated with other MRI methods to comprehensively assess tumor physiology and metabolism.

Q: Where do you see free radical imaging in the management of cancer?

A: It is not possible to image endogenously generated free radicals. But using trityl radicals, EPR Imaging can obtain oxygen maps which can be used to tailor therapy.

Q: What will it's role be in conjunction with current cancer imaging methods?

A: It will be useful along with PET and MRI.

Q: Will it have a role in drug development?

A: It can be used to assess early treatment response non-invasively and serially and cut animal costs in drug development research.

Q: What is your message to MISI?

A: I am happy to note that India has been an early entrant in the field of Molecular Imaging with leaders such as Dr. Swati Piramal and Dr. N. R. Jagannathan. With the momentum from these I wish MISI carries on with the same vigor.

Q: Your thoughts about collaborative research in the future?

A: I am open to collaborations which are synergistic.

Q: What is your advice to young researchers in this field?

A: Molecular imaging is an exciting area of research and there are plenty of opportunities. Ph. D students should actively follow literature and see what avenues they can identify in probe development, image processing, artificial intelligence for feature recognition.

DRISHTI [Issue 1, Q3, June 2020]

47 Product Review

Each quarter, we will focus on an imaging product that will familiarize the readers with latest advances in the imaging field.

MULTI-PHOTON LASER SCANNING MICROSCOPE - TECHNOLOGY TO INVESTIGATE THE DEEPER COMPLEXITY OF THE THICK SPECIMENS

The theoretical concept of the multi-photon excitation was proposed by Maria Göppert-Mayer in 1931, and later this was achieved experimentally in J. Sebastian Raja 1961 after the invention of the laser. Two-photon microscopy was developed Micro-imaging Division, DSS ImageTech Pvt. Ltd., Bengaluru in 1990 by Denk, Strickler, and Webb. Two-photon excitation occurs as a result ([email protected]) of the simultaneous absorption of two photons to excite a molecule from the ground to excited state. Two photons can interact simultaneously with a Ganesh Kadasoor molecule adding their energies to produce an excitation equal to the sum of National Manager (Applications), their distinct energies, that is, 2 red photons are equal to 1 blue photon Olympus Medical Systems India Pvt. because two photons arriving at the same time are required for excitation (Fig Ltd., Bengaluru

1). The emission depends on the square of the intensity, rather than being ([email protected]) linearly proportional. In vivo biology adapted this technique to understand the bimolecular system comprehensively. These techniques have significant advantages over the one-photon process. The Olympus FVMPE-RS – A multiphoton laser scanning microscope is one of the most distinctive and powerful systems in the world. This system is dedicated only to the nonlinear excitation process of 2-photon excitation of endogenous fluorophores, which can be used to acquire horizontal optical Fig 1: Principle of the Two-photon absorption process (A) sectioning of intact biological tissue samples. This system (Fig2) is designed for Comparative one and two-photon process show the excitation volume deep imaging in biological specimens to for both excitations1. (B) Jablonski diagram indicating the absorption reveal how cells function and interact of two photons (red arrow) to excite the fluorescent molecule to an within living tissue. This microscope excited state (S1) from (S0) and the visible fluorescence emitted employs advanced technology and optical during relaxation (green arrow) design to enhance sensitivity and resolution during deep imaging.

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48 Product Review

This system is designed for Depth- Brightness Compensation with thick specimens. It is integrated with Bright Z depth-brightness compensation, detector sensitivity, and laser power is continually

Fig 3: 3D reconstructed image of an in vivo mouse brain: Image captures using FVMPE-RS multiphoton microscope shows High- Fig 2: Olympus FVMPE-RS Resolution Deep Multiphoton Image. (Thy1-YFP-H mouse, sensory multiphoton laser scanning cortex) acquired using a TruResolution objective with an auto microscope adjustment function (left) and maximum projection images acquired at an approximately 600 μm depth. Images acquired without (top right) adjusted to maintain consistent brightness. and with (bottom right) the auto adjustment function.Images were This function complements the dynamic acquired at the RIKEN BSI-Olympus Collaboration Center, courtesy of TruResolution objectives that also Dr. Hiromu Monai, Dr.Hajime Hirase, and Dr. Atsushi automatically adjust spherical aberration Miyawaki.(adapted from https://www.olympus- compensation with depth. This option reveals the structural morphology of lifescience.com/en/laser-scanning/fvmpe-rs/) submicron features such as dendritic spine heads and necks are more clearly captured with neuron cells (Fig 3). Olympus coming up with advance objectives called as TruResolution objectives it is extensively designed for automatic spherical aberration compensation and designed for deep observation and dedicated only for Fig 4: Fluorescent microbeads (diameter = 200 nm) in a gel with Olympus FVMPE-RS multiphoton laser optical characteristics similar to live mouse brain (refractive index: 1.36, scanning microscope. TruResolution light scattering coefficient: 43 cm-1) excited at 960 nm with constant laser objectives are equipped with a computer- controlled correction collar system that power used for all images. (upper row) Microbead XZ images acquired at can automatically adjust to compensate different depths using TruResolution automatic spherical aberration for spherical aberration during deep compensation. (lower row) Microbead XZ images acquired at different observation of thick samples. When depths using a fixed correction collar initially adjusted for optimal imaging imaging deep within a sample using a at the surface of the gel. Image brightness scales are normalized at each multiphoton microscope, spherical depth. All the images were acquired with the FV30-AC25W objective. aberration reduces fluorescence intensity (adapted from https://www.olympus-lifescience.com/en/resources/white- and resolution. With the TruResolution papers/truresolution/) system, dedicated software drives a motorized correction collar using

DRISHTI [Issue 1, Q3, June 2020]

49 Product Review

Olympus’ unique algorithm, determining the optimum collar setting at each depth, quickly and accurately. For deep Z stack image acquisition, In particular, the correction collar is automatically adjusted as you observe progressively deeper into the sample. As a result, the performance of TruResolution objectives can be maximized for all depths to acquire bright and high-resolution images. Figure 4 demonstrates the potent deep imaging capabilities of TruResolution objectives using fluorescent beads embedded in a gel with a refractive index and light scattering coefficient similar to those of a live mouse brain. The bottom row of images shows the gradual degradation of the focal spot as the observation region is advanced from the top of the sample, down to 800 mm deep, without adjusting the correction collar. Notable is the smearing of the images along the z-axis and decrease in peak intensity with depth. In contrast, automatic collar adjustment using the TruResolution system delivers a more consistent compact focal spot across the different depths. The top row of images clearly shows how TruResolution improves image brightness and resolution during deep imaging. The TruResolution system is also effective with cleared tissue samples. The Refractive index varies greatly between different tissue clearing techniques and may even vary between applications of the same technique. Olympus offers 3 Microscope Frame Options . 1. Upright Microscope System — For in vivo and in vitro multiphoton microscopy This Upright Frame is completely dedicated to multiphoton microscopy. Providing space for large samples, a high degree of motorization, and nosepiece focus control enables the stage and your sample to remain fixed and stable. It is possible for the Detection of LightPath Designed for More Efficient Fluorescence Capture, Adjustable Design for the Various Sample Height Ex: The big focus stroke accommodates a wide range of specimens, from slices to mice and other small animals. It accommodates Comfortable Simultaneous Observation and Changes to Observation Conditions.The new double-deck design motorized fluorescence illuminator suppresses vibration to a minimum during mirror unit exchange. Observation conditions (i.e. multiphoton observation, fluorescence observation) can also be switched with minimal effort, even during simultaneous patch-clamp experiments. This system is available for SHG and THG Observation. The optionally transmitted fluorescence light detector expands your system's capabilities in multiphoton imaging. The dedicated high NA condenser detects transmitted fluorescence as well as transmitted second- and third-harmonic generation (SHG and THG) signals. 2. Gantry Microscope System — For in vivo observations that require more space The system with its ultra-stable arch-like structure, the new gantry microscope system offers a high degree of flexibility to suit different samples. This is ideal for in vivo observation requiring maximum space.This system is Intravital multiphoton microscopy with its ultra-stable arch- like structure, the new gantry microscope system offers a high degree of flexibility to suit different samples. This is ideal for in vivo observation requiring maximum space.it detection LightPath Designed for More Efficient Fluorescence Capture. The non-descanned detectors are very sensitive towards any interfering light. The black microscope frame reduces undesired light reflections. This has the possibility for Three-dimensional Adjustment with a removable manual XYZ stage that enables height adjustments. Changing between the thin sample and whole animal imaging can be easily accomplished. It is coming with a large workspace 3. Inverted Microscope System — for in vitro observation of 3D cell (spheroid) and tissue cultures The Inverted Microscope System is ideal for the time- lapse observation of thick cultivated cells such as tissue

DRISHTI [Issue 1, Q3, June 2020]

50 Product Review cultures, three-dimensional cultures, and cell cultures (spheroid), as well as intravital time-lapse observation of organs and tissues through a body window. This is an Inverted Microscope System is ideal for the time-lapse observation of thick cultivated cells such as tissue cultures, as well as intravital time-lapse observation of organs and tissues through a body window. This system is Ideal for 3D cultures and multicellular clusters (spheroids) This is an inverted frame ideally supports observations of 3D cultures and multicellular clusters (spheroids), which were difficult to manipulate with upright frames. It is improved for Non-descanned Detection. The optical performance of the IX83 fully automated high-end research microscope was optimized to efficiently collect scattered fluorescence light. Non-descanned detection performance is improved as compared to conventional inverted multiphoton microscope systems. Conclusion This most powerful Olympus FVMPE-RS multiphoton laser scanning microscope has distinct features 1. Optimized for deep observation. Deep Focus Mode Elevates Light-Condensation Performance for Specimens with Heavy Scattering. The Depth-Brightness Compensation Keeps Brightness Consistent from the Surface to Deep Levels 2. Detection LightPath Redesigned for More Efficient Fluorescence Capture. This setup is highly dedicated to a two- photon microscope. 3. The Deep Observation of In Vivo and Fixed Transparent Specimens Through Dedicated Multi Photon Objectives with a Maximum Depth of 8 mm. It is the maximum depth penetrable microscope in the market. 4. Specially designed Silicone Immersion Objectives for Live Imaging 5. This system contains high precision laser beam control up to 1300nm for flexible dual –Line Multiphoton imaging. InSight DS Supports Simultaneous Two Laser Line Excitation and Extended NIR Multi-Photon Imaging. It can auto Correct for Laser Beam Misalignment and Pixel Shift with Quadralign 4 Axis Auto Alignment

References 1. Piston DW (2005) “When Two Is Better Than One: Elements of Intravital Microscopy” PLoS Biol 3(6): e207 2. https://www.olympus-lifescience.com/en/laser-scanning/fvmpe-rs/#!cms[focus]=cmsContent6342 3. Olympus Multi Photon Laser Scanning Microscope FVMPE-RS Catlog

DRISHTI [Issue 1, Q3, June 2020]

51 Every quarter, an outstanding image taken by our readers will be published. This quarterly, an image of a viral protein taken by Dr. J. Sebastian Raja during his post- doctoral stint at IIT, Madras is presented. I request readers to submit their images for this section IMAGE OF THE through an email to: contactmisi.india@g QUARTER mail.com ────

Nuclear translocation of viral protein X (Vpx) of HIV-2/SIV: The References illustrative image indicates that Vpx puncta localized at the 1. SP Singh, S Raja*, S nuclear periphery and progressively translocated into the Mahalingam “Lentiviral Vpx induces alteration of nucleus. The viral protein X (Vpx) of HIV-2/SIV is the most mammalian cell nuclear important determining factor for the nuclear translocation of envelope integrity”; Biochemical and viral preintegration complex (PIC) in primary non-dividing biophysical research communications 2019 Mar target cells, which is essential for the formation of viral 26; 511(1):192-198. *Co first infection. We use super resolution-structured illumination author microscopy (SR-SIM) to acquire the image in 3D and 2. SP Singh, S Raja*, S projected through Imaris volumetric image analysis. The inset Mahalingam ”Viral Protein X (Vpx) Unlocks Nuclear Pore shows the subcellular distribution pattern of oligomeric Vpx at Complex through human Nup153 Dependent the nuclear periphery in HeLa cells. Vpx (green) docked at Pathway to Promote the nuclear membrane is colocalized (yellow) with human Nuclear Translocation of Lentiviral Genome”; Nup153 (red). The image shows that Vpx interacts with human Molecular Biology of the Nup153 at the nuclear envelope and disrupts the nuclear Cell, 2020 Feb 15;31(4):304- 317. *Co first author envelope to enter into the nucleus (blue).

52 OPINION

AI IN INFECTIOUS DISEASE: PROMISE OR HYPE?

Dr. Deepak Behera

President & CEO, Medical Imaging Consultancy, San Francisco, USA

What is AI? means identifying a signature early For known history, mankind has and predict the rest of the course of used some sort of data analysis. Simple a disease or an epidemic mathematical tools are generally Traditional computing sufficient for smaller datasets. More algorithms are hard-coded. They complicated statistical analysis may be produce robust results, but with required for larger datasets. When known variables and data, and are Deepak is a nuclear data is enormous with multiple unable to respond to unforeseen medicine physician-scientist turned executive, with roles of increasing variables and unknown associations situations. Unlike physics and responsibility in clinical development and complexities, the traditional mathematics, the field of infectious and medical affairs across clinical, academic, and pharma/biotech mathematical ways of deriving an diseases suffers from having sectors. Currently, as the President inference fall short. How do we multiple unpredictable factors that and CEO of Medical Imaging manage such data? How do we draw affect infection and transmission. Consultancy based in San Francisco, he provides strategic & operational conclusions? How do we make sense of When we attempt to apply a advice & consulting to multiple it all? traditional computing solution to pharma/biotech/device companies Artificial Intelligence (AI) takes an infectious diseases problem, in the nuclear medicine/radiopharmaceutical computation to the next level by often as our understanding of industry. He also serves as the introducing cognitive aspects to big disease evolves, new variables that Secretary and Executive Committee Member, Board of Directors of the data analysis and unraveling the weren’t in the original algorithm Indo-American Society of Nuclear unknown and unanticipated. surface and throw the traditional Medicine. He completed his MBBS Why is that important? computational method off-course. from Berhampur University and received his MD Diplomate of AI makes it possible to identify AI brings computing closer to National Board in Nuclear Medicine small signals from noise - thereby emulating human cognitive in 2005. He was a translational researcher at the Department of increasing our range of detection - and functions by allowing machines to Radiology, Stanford University. His allows us to take preventative actions automatically and ceaselessly research focus is on PET imaging of before everything explodes into a incorporate and contextualize new CD8 receptors, primarily for immuno- oncologic applications. He can be catastrophe! Perhaps similar to the information. They observe, learn, reached at change in our range of visibility when understand, and respond to new deepak.behera@medicalimagingco nsultancy.com a fading headlamp in our vehicle is data just as you and I would! replaced by a super-bright halogen one. Translated to health care, this

DRISHTI [Issue 1, Q3, June 2020]

53 Opinion

What can AI do for us in infectious be at an individual level (e.g., factors such as body temperature, diseases? prophylactic therapy) or at a infection burden, clinical presentation, So, can we bring AI to infectious population-level (e.g., allocation of complications, drug sensitivity diseases? What problems can AI solve? resources in population-based spectrum, contraindications, and drug- Can AI improve diagnosis? outbreaks). drug interactions. Algorithms could The ability of AI to learn and Doesn’t that sound similar to the identify non-infectious causes of synthesize predictions by combining ‘early detection of cancer’ buzz- systemic inflammation and thereby relationships between a myriad of phrase? Catch them early when they reduce antibiotic usage. seemingly unrelated data can improve are small, and you can cure them. Or at AI could help identify immune or the accuracy and speed of diagnosis of least reduce the spread and/or therapeutic responses. It can infectious diseases. And often without complications. interrogate features of antibody the need for lengthy complicated tests. In infectious diseases, the input responses to vaccines, and even Or coordination between multiple data can be quite varied and out of the characteristics of antibodies players - doctor, patient, lab nurse, lab realm of analysis by mere human themselves to predict outcomes. Non- technician, microbiologist, office staff, intelligence. Think of considering all interventional methods could monitor etc. factors at an individual level such as patient factors, such as adherence to a As an example, a direct application age, genetics, nutrition, lifestyle, co- treatment regimen, that may affect of AI in the clinic - simple parameters existing diseases, pre-existing therapeutic efficacy. from vital signs such as respiration immunity, and behavioral traits, then AI could be used even in the drug rate, heart rate, and facial temperature merging it with extrinsic factors such development stage. It is already used – has been successfully used to classify as underlying infections in the to analyze large chemistry datasets to individuals at higher risk for influenza, community, interactions between spot likely therapeutic drugs based on for instance [Sun et al. 2015]. members of the community, the chemical and structural properties. Google already recognizes our prevalence of preventive habits, Thereby simplifying the lead faces and knows which photos belong availability of healthcare, public identification process in new drug to us. What if pathogens in patient policies, environment, and weather, development many-fold. samples could be identified faster etc. How about adding cultural Okay, so what’s the catch? without much human intervention differences, festivals, seasonal The possibilities outlined above using similar techniques? variations, and having a pet at home to are only some thoughts and examples, Can AI help understand the mix? Humanly possible? Perhaps, and by no means exhaustive. Many of epidemiology and transmission? but maybe not for a sufficient number us feel AI has a lot of potential. In addition to a single time point of humans to cover all possible However, almost every shiny new diagnosis, could we use longitudinal infections in all large and small technology is a double-edged sword. and temporal data to arrive at communities of the world. By definition, AI has a ‘mind of its own’. individual patient-level or broad Can AI be the machine to achieve it all? To that effect, several questions population/community level Can AI help in treating infectious remain to be answered. inferences? Detecting weak signals diseases? • How do we safely achieve may predict events earlier than we AI could help in the proper integration of such currently can and may enable treatment selection for each patient. In complicated technology in proactive (as opposed to reactive) the clinic, therapeutic regimens could health and disease? intervention. Such intervention could be adapted or personalized based on

DRISHTI [Issue 1, Q3, June 2020]

54 Opinion

• How do we harmonize AI ublica.org/article/machine- higher-risk patients within ten seconds across multiple institutions, bias-risk-assessments-in- using a neural network and the fuzzy countries, states, criminal-sentencing grouping method. J. Infect. 70 (3), 230–236. Shen, Y., Yuan, K., Chen, D., Colloc, J., populations? Your thoughts: Yang, M., Li, Y., Lei, K., 2018. An ontology- • Can data collected for AI be What do you think? Is AI the driven clinical decision support system solution to take our battle against misused for political or (IDDAP) for infectious disease diagnosis financial gains? infectious diseases to the next level? Or and antibiotic prescription. Artif. Intell. • Will AI take away our jobs? are we digging our own graves? Med. 86, 20–32. • How will we protect There are no right or wrong ourselves against artificial answers. Please share your thoughts, stupidity – mistakes that feelings, fears, and hopes. artificial intelligence makes? References Sun, G., Matsui, T., Hakozaki, Y., Abe, S., • Will our existing biases be 2015. An infectious disease/fever magnified? screening radar system which stratifies Example: https://www.prop

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Uma Maheswari Krishnan

DRISHTI [Issue 1, Q3, June 2020]

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