HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wasserman, B. A. Articles by Arai, A. E. Search for Related Content PubMed PubMed Citation Articles by Wasserman, B. A. Articles by Arai, A. E.

Carotid Artery Atherosclerosis: In Vivo Morphologic Characterization with Gadolinium-enhanced Double-oblique MR Imaging—Initial Results¹

¹ From the Department of Radiology, Neuroradiology Division, Johns Hopkins Hospital, 600 N Wolfe St, Phipps B-100, Baltimore, MD 21287-2182 (B.A.W.); the Laboratory of Cardiac Energetics (A.E.A, R.S.B.) and the Cardiology Branch (R.O.C.), National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Md; and the Departments of Pathology (W.I.S.) and Surgery (H.H.T.), Suburban Hospital, Bethesda, Md. Received March 22, 2001; revision requested May 1; revision received August 17; accepted September 17. Supported by the intramural program of the National Heart, Lung, and Blood Institute, protocol 98-H-0157. Address correspondence to B.A.W. (e-mail: bwasser@rad.jhu.edu).

View larger version (175K): [in a new window]   Figure 1a. Case 1. Transverse (a) precontrast (top and bottom left) and corresponding postcontrast (top and bottom right) double inversion-recovery, fast spin-echo images (repetition time msec/echo time msec = 1,000/6) and (b) T2-weighted image (1,967/63) with fat saturation were oriented through a stenosis of the distal common carotid artery at the base of the bifurcation. Images in a were obtained at adjacent levels and demonstrate heterogeneous enhancement (arrows = enhancement along the margin of the lumen, arrowheads = enhancement along the outer wall of the atheroma). Scale bars indicates 1 cm. The image in b corresponds to the bottom image in a and shows less well-defined features (arrow = hyperintense area along the margin of the lumen, arrowheads = hyperintense area along the outer wall of the atheroma). For this patient, the mean SNR for the fibrous cap on the postcontrast images was 34 and on the T2-weighted images was 17. The corresponding fibrous cap to lipid core CNRs were 14 and 7, respectively.

View larger version (134K): [in a new window]   Figure 1b. Case 1. Transverse (a) precontrast (top and bottom left) and corresponding postcontrast (top and bottom right) double inversion-recovery, fast spin-echo images (repetition time msec/echo time msec = 1,000/6) and (b) T2-weighted image (1,967/63) with fat saturation were oriented through a stenosis of the distal common carotid artery at the base of the bifurcation. Images in a were obtained at adjacent levels and demonstrate heterogeneous enhancement (arrows = enhancement along the margin of the lumen, arrowheads = enhancement along the outer wall of the atheroma). Scale bars indicates 1 cm. The image in b corresponds to the bottom image in a and shows less well-defined features (arrow = hyperintense area along the margin of the lumen, arrowheads = hyperintense area along the outer wall of the atheroma). For this patient, the mean SNR for the fibrous cap on the postcontrast images was 34 and on the T2-weighted images was 17. The corresponding fibrous cap to lipid core CNRs were 14 and 7, respectively.

View larger version (70K): [in a new window]   Figure 2. Case 1. Contiguous postcontrast double inversion-recovery, fast spin-echo images (1,000/6, 2-mm-thick sections, no gap) with fat saturation were obtained through the base of the bifurcation. Most proximal (a), middle (b), and distal (c) sections at the level of branching of the internal (solid arrow) and external (arrowhead) carotid arteries are shown. Note the curvilinear area of hypointensity (open arrows) along the outer margin of the lipid core.

View larger version (98K): [in a new window]   Figure 3a. Case 1. (a) Hematoxylin-eosin-stained histologic sections correspond to the MR images in Figure 2 and (b) a schematic that details the morphology of Figure 2, b. In a, the top row demonstrates adjacent sections from proximal (left) to distal (right). Curvilinear blue staining along the margin of the lipid core (arrowheads) represents calcification, which corresponds to the hypointense area in Figure 2. In the most distal section, note fragmentation of plaque with loss of tissue in the area of greater calcium formation (arrow). Also in a, the bottom row demonstrates corresponding sections stained with Masson trichrome that depict fibrocellular tissue (deep blue). Scale bar indicates 2 mm. In b, schematic corresponds to middle specimens in a with outlined areas of calcification (calcium), fibrocellular tissue, lipid core, and lumen.

View larger version (132K): [in a new window]   Figure 3b. Case 1. (a) Hematoxylin-eosin-stained histologic sections correspond to the MR images in Figure 2 and (b) a schematic that details the morphology of Figure 2, b. In a, the top row demonstrates adjacent sections from proximal (left) to distal (right). Curvilinear blue staining along the margin of the lipid core (arrowheads) represents calcification, which corresponds to the hypointense area in Figure 2. In the most distal section, note fragmentation of plaque with loss of tissue in the area of greater calcium formation (arrow). Also in a, the bottom row demonstrates corresponding sections stained with Masson trichrome that depict fibrocellular tissue (deep blue). Scale bar indicates 2 mm. In b, schematic corresponds to middle specimens in a with outlined areas of calcification (calcium), fibrocellular tissue, lipid core, and lumen.

View larger version (114K): [in a new window]   Figure 4. Case 2. Left: Maximum intensity progression image from a postcontrast three-dimensional MR angiogram (6.5/1.6, flip angle of 45°) of the carotid bifurcation demonstrates a filling defect (short arrows) along the outer wall of the bulb that causes severe stenosis of the origin of the internal carotid artery. An ulceration (arrowhead) is seen at its base. A nodular filling defect projects into the lumen at the base of the external carotid artery (long arrow). Right: A black-blood, double-oblique, double inversion-recovery, fast spin-echo MR image (1,764/6, 2-mm-thick sections) in the same orientation as the maximum intensity progression image delineates plaque (black arrows) along the outer wall of the bulb that causes severe stenosis, ulceration at its base (arrowhead), and nodular plaque (white solid arrow) that projects into the base of the external carotid artery. Plaque (open arrows) that lines the anterior wall of the common carotid artery was not appreciated on the MR angiogram. This image was used as a scout image for orienting transverse sections through the distal common carotid artery and through the plaque centered at the level of greatest stenosis.

View larger version (92K): [in a new window]   Figure 5a. Case 2. (a) Transverse precontrast (left) and postcontrast (right) double inversion-recovery, fast spin-echo images (900/6) were obtained with fat saturation through the distal common carotid artery in Figure 4 and (b) the corresponding histologic sections. Precontrast image (a, left) demonstrates eccentric plaque with a thin hypointense middle layer (arrow). Postcontrast image (a, right) demonstrates enhancement of the thin inner margin (arrowheads) of the plaque with some disruption anteriorly and the hypointense middle layer. Histologic section stained with hematoxylin-eosin (b, left) shows eccentric plaque with a lipid core that corresponds to the thin area of hypointensity seen at MR imaging. Histologic section stained with Masson trichrome stain (b, right) depicts the dark blue-staining fibrous cap along the inner margin (solid arrows) that corresponds to the enhancing inner margin and blends with the lipid core more anteriorly. Note the disruption (open arrow) of the fibrous cap anteriorly. Scale bar indicates 2 mm.

View larger version (65K): [in a new window]   Figure 5b. Case 2. (a) Transverse precontrast (left) and postcontrast (right) double inversion-recovery, fast spin-echo images (900/6) were obtained with fat saturation through the distal common carotid artery in Figure 4 and (b) the corresponding histologic sections. Precontrast image (a, left) demonstrates eccentric plaque with a thin hypointense middle layer (arrow). Postcontrast image (a, right) demonstrates enhancement of the thin inner margin (arrowheads) of the plaque with some disruption anteriorly and the hypointense middle layer. Histologic section stained with hematoxylin-eosin (b, left) shows eccentric plaque with a lipid core that corresponds to the thin area of hypointensity seen at MR imaging. Histologic section stained with Masson trichrome stain (b, right) depicts the dark blue-staining fibrous cap along the inner margin (solid arrows) that corresponds to the enhancing inner margin and blends with the lipid core more anteriorly. Note the disruption (open arrow) of the fibrous cap anteriorly. Scale bar indicates 2 mm.

View larger version (152K): [in a new window]   Figure 6. Case 2. Transverse precontrast (left, top and bottom) and postcontrast (right, top and bottom) double inversion-recovery, fast spin-echo images (900/6) were obtained with fat saturation and oriented through the plaque, as in Figure 4. Images were obtained at adjacent levels (top row, proximal; bottom row, distal) and demonstrate a thin region of enhancement (short black arrow) adjacent to the internal carotid artery lumen (long black arrow). A thin hypointense zone is seen immediately beneath the enhancement. Enhancement is also seen along the outer wall of the vessel (arrowheads). Curvilinear area of hypointensity (open arrow) is seen along the posterior margin of the plaque, and no enhancement is seen in the lipid core. There is apparent contrast enhancement of the venous wall. The adjacent external carotid artery (curved arrow) is also seen.

View larger version (93K): [in a new window]   Figure 7. Case 2. Histologic sections that correspond to the images in Figure 6 are stained with hematoxylin-eosin (left, top and bottom) and Masson trichrome (right, top and bottom). Note the thin fibrous cap (arrow) that enhanced in Figure 6. Fragmentation and tissue loss with blue staining with hematoxylin-eosin represents calcification and corresponds to a curvilinear area of hypointensity in Figure 6. A small area of calcification (arrowhead) is seen subjacent to the fibrous cap that corresponds to the thin hypointense layer beneath the cap in Figure 6. This area of calcification was confirmed at high-power microscopy (not shown). Scale bar indicates 2 mm.

View larger version (21K): [in a new window]   Figure 8. Bar graph depicts SNR for the fibrous cap and CNR for the fibrous cap and lipid core in a comparison of T2-weighted (T2W) MR images with postcontrast MR images obtained with short (every heartbeat, 1RR) or long (every other heartbeat, 2RR) TRs. The SNR of the fibrous cap was higher on postcontrast images than on T2-weighted images (P < .001). On the same images, CNR for the postcontrast images was the same as or higher than that for the T2-weighted images (P = .58 and P = .21, respectively).