Loch Lomond
Infection & Inflammation Dr Sai Han Consultant in Nuclear Medicine & PET/CT NHS Greater Glasgow & Clyde Topics
Infection & Inflammation basics Tracers Clinical conditions Example Images Inflammation/ Infection
Local response to Injury (bacteria, trauma, immune..) 1st line of body defence
Vasodilatation vascular Permeability WBC migration
Cardinal signs(Rubor, Dolar, Calor, Tumor, Functio Laesa) Inflamed (red, painful, hot, swollen, function loss) Septic or Aseptic inflammation Inflammation vs tumour Acute or Chronic
Treatment treat the cause/ symptom/ complications Challenges
Inflammtion vs Tumour Septic vs aseptic inflammation Reactive vs infection Some relevant infection/inflammation
MSK Diabetic foot infection Osteomyelitis Discitis Prosthetic joint infection
GI IBD, infection Device site infection FUO Fever of Unknown Origin
Vasculitis Sarcoidosis Injury (infection, immune..)
Inflammatory Response
Vasodilatation Permeability Cell response WBC (warm, red) (swelling) Local Tissue
3 phase Bone scan WBC scans Gallium scan FDG PET Inflammation Acute Chronic onset cells Microphages Macrophages (Neutrophils>) (Monocyte, lymphocyte) example cellulitis TB pneumonia Sarcoidosis outcome resolution persist chronic granuloma damage fibrosis Diagnostics
Clinical History (* technologist) Cardinal signs Examination Labs inflammatory markers ESR, CRP…. micro, immuno, path Culture, biopsy.. Imaging Structural Swelling/ oedema, USS, MRI abscess, XR, CT destruction… Functional Inflammation: ↑ General: WBC, Ga67, FDG Necrosis: activity Specific: Bone Hybrid (SPECT/CT, PET/CT) Conventional Nuclear Imaging (Planar & SPECT) Advantages Issues Whole Body Imaging Localisation & Characterisation High Sensitivity Low Specificity Widely available Often require further tests Radiation Hybrid SPECT/CT adding CT to Nuclear Medicine Improvements Issues Localisation & Characterisation Radiation Attenuation Correction Scan time (SPECT) Specificity patient & staff Sensitivity Reporting time Diagnostic confidence Multimodality training Conclusive Reports Inconclusive Reports Further tests Time to Treatment Tracers
• General Inflammatory (WBC, Ga67, FDG) • Specific Site (e.g. MDP..) Inflammatory Tracers (ARSAC)
Tracer s T 1/2 Energy DRL Dose (KeV) MBq mSv Investigations
Tc99m 6h 140 200 2.5 Infection/inflammation wbc In111 68h 173, 247 20 7.2 Infection/inflammation wbc Ga67 78h 93, 185, 150 15 Infection/Inflammation 300, 394 F18 110 511 400 7.6 Infection/Inflammation FDG min Tumour Labelled WBC
Precaution Infection risk (staff + patient) Careful not to damage WBC Re inject ASAP (<1hr after labelling)
Procedure (EANM guidelines 2010) In-111 WBC
• Now largely replaced by Tc-99m HMPAO • Image quality, dose, but Better in specific conditions (GI, Renal) • Normal distribution: Liver, Spleen, Bone Marrow. Transient Lung • Very Low Urinary & GI excretion Tc99m HMPAO WBC
Trapped in WBC Physiological excretion (GI,Urinary) In-111 white cell Normal distribution : Transiently in lung but mainly in spleen, liver, bone marrow, vascular Tc-99m HMPAO wbc
Labelled cells •initially concentrate in lungs Subsequent highest activity in spleen But also •Liver •Bone marrow •Blood pool Tc-99m vs In-111 Tc-HMPAO In-111 oxine Better image quality Better labelling efficiency 2.2mSv 7.2 mSv Physiological GI & Renal No physiological GI & Renal Better availability Dual tracer imaging (In111wbc/Tc colloid) EANM guidelines Tc99m WBC Bowel Infection/Inflammation
WBC scan Case: SPECT/CT WBC perinephric abscess Case: PUO (Diverticular Abscess)
Pattern Recognition: Megacolon Crohn’s vs Ulcerative Colitis IBD Meta-analysis (1984-2004)
N SS SP In 682 88 93 Tc 1427 88 92 Scope 58 91 72 Ba 167 67 77
(Alessio et al. NMC. 2005.26(7) 657-664) Other Colitis: C Dif Case: 30 y F post op ? underlying bowel inflammation
Wound Only + Ga67
Excretion: Renal 10% in first 24hr Colon excretion later Soft tissue/liver/bone/bone marrow Nasopharyngeal, lacrimal, Breast Plasma protein bound (transferrin) Increased flow, permeability Wbc transport Intake by bacteria e.g. Staph aureus (sideropores) CJ. Palestro et al. RadioGraphics 2000; 20:1649–1660 SARCOIDOSIS
Chronic granulomatous inflammation Nodes, skin, organs, high calcium
Nuclear Medicine (Ga67, FDG) Activity ? Diagnosis of cardiac Sarcoidosis Ga-67 70 y lady with high Calcium (Sarcoidosis) FUO
Infection, inflammation, tumour, drug
Nuclear Medicine FDG (UK evidence based guidelines) Ga67 WBC Case: Fever of Unknown Origin: FDG PET-CT: Large Vessel Arteritis Steroid & Methotrexate→ good response Case: FUO In-111 wbc Tract in L thigh SPECT/CT= L femoral vein Doppler USS confirmed L femoral DVT Vascular device & Graft
FDG
Ref: Martin Gotthardt et al. Imaging of Inflammation by PET, conventional scintigraphy, and other imaging techniques. JNMTech 70y F CXR CT smoker LUL mass
CT-PET
LUL Lobectomy: Granulomatous inflammation → anti TB 82y♂ Cerebellar symptoms, ? Occult cancer
Small Neck node Biopsy: TB !
√ PET (+)ve lesion can be B9 curable disease FDG PET/CT in patients with HIV Cerebral Toxoplasmosis vs lymphoma
JM. Davison et al. AJR 2011; 197:284–294 Semiquantitative Analysis of Brain Metabolism in Paraneoplastic Neurologic Syndrome AJ Clapp et al. Clin Nucl Med 2013 (Epub)
MRI
Limbic Encephalitis
FDG PET
Courtesy of P Peller, Mayo Clinic Specific sites e.g. Bone, Kidney, Gall Blasdder Skeletal infection/inflammation
Osteomyelitis, Diabetic foot infection Septic joint Prosthetic joint infection
Nuclear Medicine 3 phase bone WBC Diabetic Foot Infection Antibiotic: Soft tissue infection (7-10days) Bone (4 weeks)
• plain X-rays • MRI •When MRI not available or contraindicated, consider WBC scan, or (SPECT/CT) or (PET)
• 3phase bone SS 80-90 SP 30-45 (to exclude) • MR SS90 SP85 • WBC PPV 70-90 NPV 80 SS75-80 SP70-85 • WBC SPECT/CT SS 87.5 SP 71 PPV 83 NPV 78 Case. 55 y M DM; renal Transplant Ankle swelling 3 phase bone scan & In-111 WBC scan
Calcaneus Osteomyelitis Case: 35 year M
Bone scan Tibial Osteomyelitis Prosthetic Joint Pain
Septic or Aseptic Loosening Bone scan (? Reactive ? Infection)
C Love et al. Semin Nucl Med 2009. 39:66-78 In111 wbc / Tc99m Colloid Discordant WBC & Colloid uptake = ? infection
Test Accuracy (%) Bone 50 Bone/Gallium 66 WBC/bone 70 • WBC/ colloid 91
C Love et al. Semin Nucl Med 2009. 39:66-78 THYROIDITIS
Clinical; hyperthyroid, Neck pain Laboratory: increased inflammatory marker Nuclear Medicine Thyroiditis (subacute; postpartum) Low Thyroid uptake Case. Subacute thyroiditis (low thyroid uptake) Pyelonephritis
Effect: Scar Nuclear Medicine DMSA Recurrent UTI Acalculous Cholecystitis
Pain Function loss
Nuclear Medicine HIDA appearance, Gall bladder Ejection Fraction HIDA HIDA (time activity curve) Conclusions
• Nuclear Medicine helps diagnose/exclude Infection/inflammation CVS WBC & FDG (vascular graft, device, sarcoid) Sarcoid Ga67, FDG • MSK Diabetic foot (bone, wbc) Spine OM (Ga67, WBC) Prosthetic joint (bone, wbc/colloid) • PUO WBC, FDG • Also Functional effect: UTI(DMSA) GB(HIDA)
Hybrid imaging improves Thank You Acknowledgement
Colleagues at NHS GGC & Glasgow University