RT Journal Article
SR Electronic
T1 Imaging the Intracranial Atherosclerotic Vessel Wall Using 7T MRI: Initial Comparison with Histopathology
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
SP 694
OP 701
DO 10.3174/ajnr.A4178
VO 36
IS 4
A1 A.G. van der Kolk
A1 J.J.M. Zwanenburg
A1 N.P. Denswil
A1 A. Vink
A1 W.G.M. Spliet
A1 M.J.A.P. Daemen
A1 F. Visser
A1 D.W.J. Klomp
A1 P.R. Luijten
A1 J. Hendrikse
YR 2015
UL http://www.ajnr.org/content/36/4/694.abstract
AB BACKGROUND AND PURPOSE: Several studies have attempted to characterize intracranial atherosclerotic plaques by using MR imaging sequences. However, dedicated validation of these sequences with histology has not yet been performed. The current study assessed the ability of ultra-high-resolution 7T MR imaging sequences with different image contrast weightings to image plaque components, by using histology as criterion standard. MATERIALS AND METHODS: Five specimens of the circle of Wills were imaged at 7T with 0.11 × 0.11 mm in-plane-resolution proton attenuation–, T1-, T2-, and T2*-weighted sequences (through-plane resolution, 0.11–1 mm). Tissue samples from 13 fiducial-marked locations (per specimen) on MR imaging underwent histologic processing and atherosclerotic plaque classification. Reconstructed MR images were matched with histologic sections at corresponding locations. RESULTS: Forty-four samples were available for subsequent evaluation of agreement or disagreement between plaque components and image contrast differences. Of samples, 52.3% (n = 23) showed no image contrast heterogeneity; this group comprised solely no lesions or early lesions. Of samples, 25.0% (n = 11, mostly advanced lesions) showed good correlation between the spatial organization of MR imaging heterogeneities and plaque components. Areas of foamy macrophages were generally seen as proton attenuation–, T2-, and T2*- hypointense areas, while areas of increased collagen content showed more ambiguous signal intensities. Five samples showed image-contrast heterogeneity without corresponding plaque components on histology; 5 other samples showed contrast heterogeneity based on intima-media artifacts. CONCLUSIONS: MR imaging at 7T has the image contrast capable of identifying both focal intracranial vessel wall thickening and distinguishing areas of different signal intensities spatially corresponding to plaque components within more advanced atherosclerotic plaques. CoWcircle of WillisPDproton-attenuation