1. National variation in preoperative imaging, carotid duplex ultrasound criteria, and threshold for surgery for asymptomatic carotid artery stenosis 
Edward J. Arous, MD, Jessica P. Simons, MD, MPH, Julie M. Flahive, MS, Adam W. Beck, MD, David H. Stone, MD, Andrew W. Hoel, MD, Louis M. Messina, MD, Andres Schanzer, MD Jeb Hallett, MD, Christopher Abularrage, MD, Adam Beck, MD, Daniel Clair, MD, Alex Shepard, MD, Joseph Schneider, MD, Amy Reed, MD, Grace Wang, MD, Gary Lemmon, MD, Ronald Dalman, MD, Jeffrey Gilbertson, MD, Fred Weaver, MD, Mark Davies, MD, PhD, Michael Costanza, MD, Steven Kappes, MD, Evan Lipsitz, MD, Jens Jorgensen, MD, Gilbert Upchurch, MD Edward J. Arous, MD, Jessica P. Simons, MD, MPH, Julie M. Flahive, MS, Adam W. Beck, MD, David H. Stone, MD, Andrew W. Hoel, MD, Louis M. Messina, MD, Andres Schanzer, MD Jeb Hallett, MD, Christopher Abularrage, MD, Adam Beck, MD, Daniel Clair, MD, Alex Shepard, MD, Joseph Schneider, MD, Amy Reed, MD, Grace Wang, MD, Gary Lemmon, MD, Ronald Dalman, MD, Jeffrey Gilbertson, MD, Fred Weaver, MD, Mark Davies, MD, PhD, Michael Costanza, MD, Steven Kappes, MD, Evan Lipsitz, MD, Jens Jorgensen, MD, Gilbert Upchurch, MD 
Journal of Vascular Surgery 
Volume 62, Issue 4, Pages (October 2015)
DOI: /j.jvs
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

2. Fig 1
Imaging studies obtained before carotid endarterectomy (CEA) for asymptomatic carotid artery stenosis (n = 18,447). CTA, Computed tomography angiography; MRA, magnetic resonance angiography.
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

3. Fig 2
Distribution of the (A) peak systolic velocity (PSV; n = 8110), (B) end diastolic velocity (EDV; n = 7653), and (C) internal carotid artery-to common carotid artery (ICA/CCA) ratio associated with the calculated degree of stenosis obtained on carotid artery duplex ultrasound imaging. The whiskers mark the 1st and 99th percentiles.
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

4. Fig 3
Percentage of carotid endarterectomy (CEA) procedures performed at each level of asymptomatic stenosis (n = 19,306).
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

5. Fig 4
Percentage of carotid endarterectomy (CEA) procedures performed at each degree of asymptomatic carotid artery stenosis stratified by tertiles of center volume per study year (n = 18,822).
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

6. Fig 5
Surgeon variation in the percentage of carotid endarterectomies (CEAs) performed for <80% asymptomatic carotid stenosis (n = 952).
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions

7. Fig 6
Institutional variation in the percentage of carotid endarterectomies (CEAs) performed for <80% asymptomatic carotid stenosis (n = 207).
Journal of Vascular Surgery  , DOI: ( /j.jvs )
Copyright © 2015 Society for Vascular Surgery Terms and Conditions