Contrast-enhanced high resolution MRI for atherosclerotic carotid artery tissue characterization.
OBJECTIVE
To determine if a gadolinium-based contrast agent provides additional information for characterization of human plaque tissues, particularly neovasculature. Although high-resolution magnetic resonance imaging (MRI) has been used to identify plaque constituents in advanced atherosclerosis, some constituents, such as neovascularized tissue, defy detection.


METHODS
Non-contrast-enhanced carotid artery images from 18 patients scheduled for carotid endarterectomy and two normal volunteers were used to identify regions of fibrous tissue, necrotic core, or calcification, using established criteria. Then, the percent change in T1-weighted images after contrast enhancement was calculated for each region.


RESULTS
There were statistically significant differences in mean intensity change between tissues, with the largest increase for fibrous tissue (79.5%) and the smallest for necrotic core (28.6%). Additionally, histological analysis showed that a subset of fibrous regions rich in plaque neovascularization could be identified using a threshold of 80% enhancement (sensitivity = 76%, specificity = 79%).


CONCLUSIONS
The ability of contrast-enhanced MRI to identify neovascularization and potentially improve differentiation of necrotic core from fibrous tissue further establishes MRI as a viable tool for in vivo study of atherosclerotic plaque.
Yuan
Chun
C
University of Washington, School of Medicine, Seattle, Washington 98195-7115, USA. cyuan@u.washington.edu
Kerwin
William S
WS
Ferguson
Marina S
MS
Polissar
Nayak
N
Zhang
Shaoxiong
S
Cai
Jianming
J
Hatsukami
Thomas S
TS
D000704:Analysis of Variance; D001161:Arteriosclerosis / Q000473:pathology*; D002340:Carotid Artery Diseases / Q000473:pathology* / Q000601:surgery; D016022:Case-Control Studies; D003287:Contrast Media / Q000008:administration & dosage; D016894:Endarterectomy, Carotid; D019786:Gadolinium DTPA / Q000008:administration & dosage; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009389:Neovascularization, Pathologic / Q000473:pathology; D012680:Sensitivity and Specificity
D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA