High-resolution magnetic resonance imaging for detection of carotid plaques

OBJECTIVE: We report our experience using high-resolution magnetic resonance imaging (MRI) to identify carotid plaques and also discuss these MRI findings while comparing them with carotid endarterectomy specimens. METHODS: Eighteen carotid plaques from 17 different patients were observed using plaque MRI. The patients included 14 men and 3 women, aged 53 to 75 years (mean, 68.6 yr). Eight patients experienced a stroke and four patients experienced transient ischemic attack. The remaining five patients did not experience any neurological symptoms. Two-dimensional time-of-flight (TOE) MR angiography; T1-weighted imaging; fat-suppressed, cardiac gated, black-blood proton density imaging; and T2-weighted imaging were obtained with a 1.5-T MRI. RESULTS: Symptomatic plaques showed either vast or partially dotted high signals for each contrast. The high signal intensity on time-of-flight and T2-weighted imaging predicted the instability of the plaques (100% sensitivity and specificity). In particular, time-of-flight imaging predicted intraplaque hemorrhaging with 100% sensitivity and 80% specificity. MRI revealed that three of four asymptomatic lesions were unstable plaques. CONCLUSION: High-resolution MRI was able to detect various signal patterns related to the plaque components, and it was thus considered to be very useful for evaluating plaque instability. The application of plaque MRI therefore may positively affect the decision-making process when selecting optimal therapeutic strategies to treat with carotid plaques.