1. Acoustic shadowing impairs accurate characterization of stenosis in carotid ultrasound examinations 
Jahan Mohebali, MD, MPH, Virendra I. Patel, MD, MPH, Javier M. Romero, MD, Kathleen M. Hannon, MS, Michael R. Jaff, DO, Richard P. Cambria, MD, Glenn M. LaMuraglia, MD 
Journal of Vascular Surgery 
Volume 62, Issue 5, Pages (November 2015)
DOI: /j.jvs
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

2. Fig 1
A typical acoustic shadow (AcS), which prevents interrogation of an area of the vessel lumen, is outlined (blue).
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

3. Fig 2
a, The red bars depict the acceleration time (∼240 milliseconds). The diagonal yellow line depicts the acceleration slope. b, The red bracket shows the change in velocity from the peak to 200 milliseconds beyond the peak. This change corresponds to deceleration, and the diagonal yellow line identifies the deceleration slope.
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

4. Fig 3
Left image shows multidetector computed tomographic angiography (MD-CTA) viewing window optimized to demonstrate calcified plaque and residual lumens at width (W) of 700 and level (L) of 300. Right image shows pixel averaging, which results in an incorrect overestimation of stenosis.
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

5. Fig 4
a, North American Symptomatic Carotid Endarterectomy Trial (NASCET) method. The residual lumen is outlined to determine cross-sectional area, which is compared to a “normal” reference area in the more distal internal carotid artery (ICA). Percent stenosis = 100 × (Reference area − residual lumen area)/Reference area. This corresponds to (30.5 mm2 − 4.5 mm2)/30.5 mm2 × 100 = 85% for the figure shown. b, European Carotid Surgery Trial (ECST) method. The residual lumen and “normal” lumen are outlined at the point of maximal stenosis bilaterally to determine cross-sectional area. Percent stenosis is calculated as 100 × (Normal artery area − residual lumen area)/Normal artery area. This corresponds to (40.9 mm2 − 4.5 mm2)/40.9 mm2 × 100 = 89% for the figure shown.
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions