Multicontrast High-Resolution Vessel Wall Magnetic Resonance Imaging and Its Value in Differentiating Intracranial Vasculopathic Processes

Abstract

Background and Purpose-Although studies have attempted to differentiate intracranial vascular disease using vessel wall magnetic resonance imaging (VWI), none have incorporated multicontrast imaging. This study uses T1-and T2-weighted VWI to differentiate intracranial vasculopathies. Methods-We retrospectively reviewed patients with clinically defined intracranial vasculopathies causing luminal stenosis/ irregularity who underwent VWI studies. Two blinded experts evaluated T1 precontrast and postcontrast and T2-weighted VWI characteristics, including the pattern of wall thickening; presence, pattern, and intensity of postcontrast enhancement; and T2 signal characteristics. Results-Twenty-one cases of atherosclerosis (intracranial atherosclerotic disease [ICAD]), 4 of reversible cerebral vasoconstriction syndrome, and 4 of vasculitis were identified, with a total of 118 stenotic lesions (81 ICAD, 22 reversible cerebral vasoconstriction syndrome, and 15 vasculitic lesions). There was substantial to excellent inter-reader agreement for the assessment of lesional T2 hyperintensity (κ=0.80), pattern of wall thickening (κ=0.87), presence (κ=0.90), pattern (κ=0.73), and intensity (κ=0.77) of enhancement. ICAD lesions were significantly more likely to have eccentric wall involvement (90.1%) than reversible cerebral vasoconstriction syndrome (8.2%; P<0.001) and vasculitic lesions (6.7%; P<0.001) and were also more likely to have T2 hyperintensity present than the other 2 vasculopathies (79% versus 0%; P<0.001). There were also significant differences in the presence, intensity, and pattern of enhancement between all lesion types. Combining T1 and T2 VWI increased the sensitivity of VWI in differentiating ICAD from other vasculopathies from 90.1% to 96.3%. on VWI has been described and shown to correspond to the fibrous cap on histology. 15 In contrast, the T2 hypointense outer component of the plaque corresponds to areas rich in foamy macrophages and proteoglycans, and lipid rich necrotic core on T2-weighted VWI. 16 To our knowledge, no reports have used T2-weighted high-resolution VWI and multicontrast protocols as a technique to discriminate between vasculopathies. In this study, we evaluated the imaging findings of different vasculopathies on T2 and T1 pre and postcontrast imaging to identify unique features and test their ability to correctly identify disease and develop an algorithm to differentiate intracranial vasculopathies. We also investigate the additional benefit of using multicontrast VWI over pre and postcontrast T1 alone to differentiate disease. Conclusions-Multicontrast Methods Patient Population and Clinical DiagnosisAfter institutional review board approval, we reviewed consecutive patients from January 2011 to April 2014 with suspicion of intracranial vasculopathy who had VWI and, on luminal imaging, had appreciable intracranial arterial stenosis or irregularity. There were a total of 68 patients, who had 77 high-resolution VWI studies performed. Patients were further stratified into diagnostic vascu...

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