In vivo identification of complicated upper thoracic aorta and arch vessel plaque by MR direct thrombus imaging in patients investigated for cerebrovascular disease.
OBJECTIVE
The objective of this article was to assess the feasibility of MR direct thrombus imaging (MRDTI) to evaluate the prevalence and location of complicated upper thoracic aortic and arch vessel plaque in patients referred for evaluation of cerebrovascular disease.


METHODS
Patients referred for investigation of cerebrovascular disease by MRI were enrolled. Reasons for referral included transient ischemic attack/amaurosis fugax, acute infarct, remote infarct, or asymptomatic carotid disease. Of the 348 patients initially scanned, 17 were excluded from the analysis. The final patient population included 331 patients (199 men, 132 women; mean age, 67.7 years). Patients were scanned using MRDTI, a 3D, T1-weighted, fat-suppressed spoiled gradient echo that exploits the T1 shortening effects of methemoglobin, directly visualizing hemorrhage/thrombus in the vessel wall, thus identifying complicated plaque. Complicated plaque was defined as a high signal within the atherosclerotic plaque at least twice the signal intensity of muscle.


RESULTS
Forty-three of 331 patients (13%) had complicated upper thoracic aortic atherosclerotic disease, arch vessel atherosclerotic disease, or both. The upper thoracic aorta was involved in 36 of 43 patients (83.7%), and the left subclavian artery was involved in 14 of 43 patients (32.6%). Both the right subclavian artery and the brachiocephalic artery were involved in one of 43 patients (2.3%). Complicated carotid plaque was seen in 25 of 43 patients (58.1%).


CONCLUSIONS
MRDTI can be applied in the detection of complicated plaque in the upper thoracic aorta and arch vessels. Complicated plaque was identified in 13% of the patient population. The upper thoracic aorta was the most common site involved. This technique could be useful for the screening of asymptomatic at-risk patients.
Bitar
Richard
R
Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada.
Moody
Alan R
AR
Leung
General
G
Kiss
Alexander
A
Gladstone
David
D
Sahlas
Demetrios J
DJ
Maggisano
Robert
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000473:pathology*; D001018:Aortic Diseases / Q000175:diagnosis*; D050197:Atherosclerosis / Q000175:diagnosis*; D016893:Carotid Stenosis / Q000175:diagnosis; D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000209:etiology; D003287:Contrast Media; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D013348:Subclavian Artery / Q000473:pathology; D013927:Thrombosis / Q000175:diagnosis*
D003287:Contrast Media