Challenges & Pitfalls in Imaging of Carotid Faezeh Jean S. Noreen Osvaldo Jonathan Brittany Razjouyan Rowe Islam Mercado Nakata Bryant Faezeh Razjouyan, MS2; Jean S. Rowe, BS2; Noreen Islam, MPH2; Brittany Bryant, BS2; Isaac M. E. Dodd, MS2; Sanchez Colo, PharmD-MBA2; Weonpo Yarl, MS2; Shakita Crichlow, BS2; Osvaldo Mercado, BS2; Jonathan Nakata, BS2; Kamyar Sartip, MD1; Han Y. Kim, MD1; Bonnie Davis, MD1; Andre J. Duerinckx, MD-PhD1

Isaac E Sanchez Weonpo Shakita Kamyar A. Han Y. Bonnie Dodd Colo Yarl Crichlow 1 2 Andre J. Department of , Howard University College of Medicine , Washington, D.C. 20059 Sartip Kim Davis Duerinckx

Goals 1. Reporting Error 2. Limitation in Analysis

• Access the results of novel research and world (Satisfaction of Search) (High Resistance Flow) literature on the usage and pitfalls of in the evaluation of carotid anatomy and disease.

• Recognize the standard practice guidelines for carotid ultrasonography and optimal scanning techniques and Doppler settings.

• Better understand the potential for operator-and patient-related pitfalls and discrepancies during (a) (b) (c) the performance of carotid ultrasound. (b) Challenges & Background Pitfalls

• is the fourth leading cause of death in the of (a) United States according to the Centers for Disease Control and Prevention (CDC). Carotid (e) (d) (c) • Evaluating carotid artery disease (or carotid artery Sonography stenosis) is an important step in investigating the A 66 y/o woman presented in Nov 2014 with acute stroke An 87 y/o woman presented to the ED with headaches. The symptoms. MRI confirmed acute stroke in the left hemisphere (a, initial CT (not shown) revealed a chronic left middle cerebral etiology of stroke. arrow), as well as severe stenosis/near occlusion in the supraclinoid artery (MCA) distribution infarct. A follow up MRI two days left internal carotid artery (ICA) (b, arrow). An initial carotid later confirmed a large left MCA infarct (a, arrow). An MRA of • Several imaging modalities are used to screen for ultrasound suggested total occlusion (c, arrow) of the proximal left the carotid was not performed, but an MRA of the circle of ICA. Because of the discrepancy between the MRA and the Willis (not shown) did not show significant lesions. A carotid carotid stenosis, including carotid ultrasonography, ultrasound, a repeat carotid ultrasound was performed 7 days later, ultrasound performed the next day showed bilateral which is one of the least expensive and most well- and revealed that the left ICA was fully patent (d,e, arrows). increased resistive flow in the ICAs (b, c). The implications

established imaging modalities to achieve this of this abnormality are unknown.

goal. 3. Interpretation Error • Performing successful carotid sonographic studies 4. Technical Error requires an awareness of commonly encountered (Underreporting Carotid Stenosis) pitfalls, such as technical factors and interpretation (“Aliasing” Artifact) errors.

87 y/o woman with dizziness and altered • We reviewed the world literature on the mental status (AMS) presented to the advantages and disadvantages of ultrasound ED on two occasions in Nov and Dec imaging to detect and characterize carotid 2014, and each time a CT study (not shown) was done and was normal. A A 78 y/o woman is being diseases. follow up MRI / MRA of the brain in late followed for altered Dec 2014 for severe AMS showed (a) mental status and an moderate focal stenosis of the proximal (a) (b) (c) evolving subacute infarct right common carotid artery (CCA) (a, in the left parietal lobe. arrow). Conclusion An initial carotid

ultrasound in Oct 2013 A follow up carotid ultrasound showed a was normal (a). A follow Ultrasound is an excellent modality for diagnosis and right CCA lesion with peak systolic up carotid ultrasound velocity of 391 cm/sec (b, c). Three days surveillance of carotid stenosis since it is non- one year later suggested later a CT angiogram of the carotid invasive, relatively accurate, and inexpensive. a mild right ICA stenosis arteries was performed to better (b, arrow), caused by a Knowledge of pitfalls, limitations, and artifacts visualize the right CCA lesion. machine error in tracing

encountered during an examination will improve the (d) (e) an aliasing artifact. accuracy of the study and enhance risk stratification Cross sectional axial images (d,e, arrows) clearly show a severe right CCA (b) for stroke therapy. lesion (red arrows) compared to a normal left CAA (green arrows). This is confirmed on the 3D rendered images of the diseased right CCA (f, red arrow) References and the normal left CCA (g, green arrow). • Arning C et al. The diagnostic relevance of colour Doppler artefacts in carotid artery examinations. European Journal of Radiology. 2004; 51(3):246-51. • Ferguson G et al. The North American Symptomatic Carotid Trial Surgical Results in 1415 Patients. Stroke. 1999; 30(9):1751-58. (f) (g) Howard University Research Day, Washington, DC, April 16, 2015; • Partovi S et. al Contrast-Enhanced Ultrasound for Assessing Carotid Atherosclerotic Plaque Radiology Update for Clinicians 2015, Delaware Radiological Lesions. American Journal of Roentgenology 2012;198(1):W13-9 Society, Newark, Delaware, April 25, 2015; Second Imaging Symposium, Dept of Radiology, Howard university, May 1, 2015; Radiology Section Mtg at NMA 2015 in Detroit, MI, Aug 1-5, 2015