Magnetic resonance imaging of carotid atherosclerotic plaque in clinically suspected acute transient ischemic attack and acute ischemic stroke.
BACKGROUND
Carotid atherosclerotic plaque rupture is thought to cause transient ischemic attack (TIA) and ischemic stroke (IS). Pathological hallmarks of these plaques have been identified through observational studies. Although generally accepted, the relationship between cerebral thromboembolism and in situ atherosclerotic plaque morphology has never been directly observed noninvasively in the acute setting.


RESULTS
Consecutive acutely symptomatic patients referred for stroke protocol magnetic resonance imaging/angiography underwent additional T1- and T2-weighted carotid bifurcation imaging with the use of a 3-dimensional technique with blood signal suppression. Two blinded reviewers performed plaque gradings according to the American Heart Association classification system. Discharge outcomes and brain magnetic resonance imaging results were obtained. Image quality for plaque characterization was adequate in 86 of 106 patients (81%). Eight TIA/IS patients with noncarotid pathogenesis were excluded, yielding 78 study patients (38 men and 40 women with a mean age of 64.3 years, SD 14.7) with 156 paired watershed vessel/cerebral hemisphere observations. Thirty-seven patients had 40 TIA/IS events. There was a significant association between type VI plaque (demonstrating cap rupture, hemorrhage, and/or thrombosis) and ipsilateral TIA/IS (P<0.001). A multiple logistic regression model including standard Framingham risk factors and type VI plaque was constructed. Type VI plaque was the dominant outcome-associated observation achieving significance (P<0.0001; odds ratio, 11.66; 95% confidence interval, 5.31 to 25.60).


CONCLUSIONS
In situ type VI carotid bifurcation region plaque identified by magnetic resonance imaging is associated with ipsilateral acute TIA/IS as an independent identifier of events, thereby supporting the dominant disease pathophysiology.
Department of Radiology, University of Virginia Health System, Charlottesville, USA. jaywant.parmar@gmail.com
Jaywant P
JP
Parmar
Walter J
WJ
Rogers
John P
JP
Mugler
Erol
E
Baskurt
Talissa A
TA
Altes
Kiran R
KR
Nandalur
George J
GJ
Stukenborg
C Douglas
CD
Phillips
Klaus D
KD
Hagspiel
Alan H
AH
Matsumoto
Michael D
MD
Dake
Christopher M
CM
Kramer
D000368:Aged; D050197:Atherosclerosis / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D002340:Carotid Artery Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D020767:Intracranial Thrombosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D016015:Logistic Models; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012307:Risk Factors; D020521:Stroke / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology