Middle Cerebral Artery Atherosclerotic Plaques in Recent Small Subcortical Infarction: A Three-Dimensional High-resolution MR Study

Abstract

Purpose: Conventional two-dimensional vessel wall imaging has been used to depict the middle cerebral artery (MCA) wall in patients with recent small subcortical infarctions (RSSIs). However, its clinical use has been limited by restricted spatial coverage, low signal-to-noise ratio (SNR), and long scan time. We used a novel three-dimensional high-resolution MR imaging (3D HR-MRI) technique to investigate the presence, locations, and contrast-enhanced patterns of MCA plaques and their relationship with RSSI.

Methods: Nineteen consecutive patients with RSSI but no luminal stenosis on MR angiography were prospectively enrolled. 3D HR-MRI was performed using a T1w-SPACE sequence at 3.0 T. The presence, locations, and contrast-enhanced patterns of the MCA plaques on the ipsilateral and contralateral sides to the RSSI were analyzed.

Results: Eighteen patients successfully completed the study. MCA atherosclerotic plaques occurred more frequently on the ipsilateral than the contralateral side to the RSSI (72.2% versus 33.3%, P = 0.044). The occurrence of superiorly located plaques was significantly higher on the ipsilateral than the contralateral side of the MCA (66.7% versus 27.8%; P = 0.044).

Conclusions: Superiorly located plaques are closely associated with RSSI. 3D high-resolution vessel wall imaging may be a potential tool for etiologic assessment of ischemic stroke.

Figure 1

Contrast-enhanced 3D HR-MRI images from three patients. (a)–(c): MRA images show no stenosis on the relevant MCAs in these patients (short dash line). (d)–(f): Contrast-enhanced 3D HR-MRI images of the corresponding patients show the plaques and their positions along the MCAs (see arrow): (d) superiorly located superior; (e) inferiorly located plaque; (f) plaque involving both superior and inferior wall.

Figure 2

A 56-year-old man with right-side weakness and dysarthria. (a) MRA shows no stenosis on the left MCA; (b) the diffusion-weighted image shows a hypertensive lesion in the left lenticular nucleus with rostral extension to the coronal radiate; (c) the T1-weighted SPACE postcontrast images show apparent eccentric wall thickening (arrow) in close proximity to bifurcation ipsilateral to the infarction on both the long axis and the short axis of the vessel.

Figure 3

A 59-year-old man with left-side weakness. (a) MRA shows no stenosis on right MCA; (b) the diffusion-weighted image shows a hypertensive lesion in the right lenticular nucleus which extends to the coronal radiate; precontrast T1-weighted SPACE images did not show eccentric wall thickening clearly on both the long axis (c) and short axis ((e), arrow) of the MCA; postcontrast T1-weighted SPACE images show wall thickening ipsilateral to the infarct on both the long axis (d) and short axis ((f), arrow) of the MCA.