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PT  - JOURNAL ARTICLE
AU  - Etesami, M.
AU  - Hoi, Y.
AU  - Steinman, D.A.
AU  - Gujar, S.K.
AU  - Nidecker, A.E.
AU  - Astor, B.C.
AU  - Portanova, A.
AU  - Qiao, Y.
AU  - Abdalla, W.M.A.
AU  - Wasserman, B.A.
TI  - Comparison of Carotid Plaque Ulcer Detection Using Contrast-Enhanced and Time-of-Flight MRA Techniques
AID  - 10.3174/ajnr.A3132
DP  - 2012 May 24
TA  - American Journal of Neuroradiology
4099  - http://www.ajnr.org/content/early/2012/05/24/ajnr.A3132.short
4100  - http://www.ajnr.org/content/early/2012/05/24/ajnr.A3132.full
AB  - BACKGROUND AND PURPOSE: Ulceration in carotid plaque is a risk indicator for ischemic stroke. Our aim was to compare plaque ulcer detection by standard TOF and CE-MRA techniques and to identify factors that influence its detection. MATERIALS AND METHODS: Carotid MR imaging scans were acquired on 2066 participants in the ARIC study. We studied the 600 thickest plaques. TOF-MRA, CE-MRA, and black-blood MR images were analyzed together to define ulcer presence (plaque surface niche ≥2 mm in depth). Sixty ulcerated arteries were detected. These arteries were randomly assigned, along with 40 nonulcerated plaques from the remaining 540, for evaluation of ulcer presence by 2 neuroradiologists. Associations between ulcer detection and ulcer characteristics, including orientation, location, and size, were determined and explored by CFD modeling. RESULTS: One CE-MRA and 3 TOF-MRAs were noninterpretable and excluded. Of 71 ulcers in 56 arteries, readers detected an average of 39 (55%) on both TOF-MRA and CE-MRA, 26.5 (37.5%) only on CE-MRA, and 1 (1.5%) only on TOF-MRA, missing 4.5 (6%) ulcers by both methods. Ulcer detection by TOF-MRA was associated with its orientation (distally pointing versus perpendicular: OR = 5.57 [95% CI, 1.08–28.65]; proximally pointing versus perpendicular: OR = 0.21 [95% CI, 0.14–0.29]); location relative to point of maximum stenosis (distal versus isolevel: OR = 5.17 [95% CI, 2.10–12.70]); and neck-to-depth ratio (OR = 1.96 [95% CI, 1.11–3.45]) after controlling for stenosis and ulcer volume. CONCLUSIONS: CE-MRA detects more ulcers than TOF-MRA in carotid plaques. Missed ulcers on TOF-MRA are influenced by ulcer orientation, location relative to point of maximum stenosis, and neck-to-depth ratio. Abbreviations ARICAtherosclerosis Risk in CommunitiesCEcontrast-enhancedCFDcomputational fluid dynamicsCIconfidence intervalFDflow dividerIMTintima-media thicknessIQimage qualityMIPmaximum intensity projectionORodds ratioTOFtime-of-flight