Intracranial plaque enhancement in patients with cerebrovascular events on high-spatial-resolution MR images.
OBJECTIVE
To characterize intracranial plaque inflammation in vivo by using three-dimensional (3D) high-spatial-resolution contrast material-enhanced black-blood (BB) magnetic resonance (MR) imaging and to investigate the relationship between intracranial plaque inflammation and cerebrovascular ischemic events.


METHODS
The study was approved by the institutional review board and was HIPAA compliant. Twenty-seven patients (19 men; mean age, 56.8 years ± 12.4 [standard deviation]) with cerebrovascular ischemic events (acute stroke, n = 20; subacute stroke, n = 2; chronic stroke, n = 3; transient ischemic attack, n = 2) underwent 3D time-of-flight MR angiography and contrast-enhanced BB 3-T MR imaging for intracranial atherosclerotic disease. Each identified plaque was classified as either culprit (the only or most stenotic lesion upstream from a stroke), probably culprit (not the most stenotic lesion upstream from a stroke), or nonculprit (not within the vascular territory of a stroke). Plaque contrast enhancement was categorized on BB MR images (grade 0, enhancement less than or equal to that of normal arterial walls seen elsewhere; grade 1, enhancement greater than grade 0 but less than that of the pituitary infundibulum; grade 2, enhancement greater than or equal to that of the pituitary infundibulum), and degree of contrast enhancement was calculated. Associations of the likelihood of being a culprit lesion with both plaque contrast enhancement and plaque thickness were estimated with ordinal logistic regression.


RESULTS
Seventy-eight plaques were identified in 20 patients with acute stroke (21 [27%] culprit, 12 [15%] probably culprit, and 45 [58%] nonculprit plaques). In these patients, grade 2 contrast enhancement was associated with culprit plaques (odds ratio 34.6; 95% confidence interval: 4.5, 266.5 compared with grade 0) when adjusted for plaque thickness. Grade 0 was observed in only nonculprit plaques. Culprit plaques had a higher degree of contrast enhancement than did nonculprit plaques (25.9% ± 13.4 vs 13.6% ± 12.3, P = .003).


CONCLUSIONS
Contrast enhancement of intracranial atherosclerotic plaque is associated with its likelihood to have caused a recent ischemic event and may serve as a marker of its stability, thereby providing important insight into stroke risk.
From the Russell H. Morgan Department of Radiology and Radiological Sciences (Y.Q., S.M., B.A.W.) and Department of Neurology (S.R.Z., R.L., V.U., R.W.), Johns Hopkins Hospital, Johns Hopkins University School of Medicine, 367 East Park Building, 600 N Wolfe St, Baltimore, MD 21287.
Ye
Y
Qiao
Steven R
SR
Zeiler
Saeedeh
S
Mirbagheri
Richard
R
Leigh
Victor
V
Urrutia
Robert
R
Wityk
Bruce A
BA
Wasserman
D002545:Brain Ischemia / Q000209:etiology* / Q000473:pathology*; D003287:Contrast Media; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods; D008875:Middle Aged; D058226:Plaque, Atherosclerotic / Q000150:complications* / Q000473:pathology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012307:Risk Factors; D020521:Stroke / Q000209:etiology* / Q000473:pathology*
D003287:Contrast Media; D019786:Gadolinium DTPA