MR angiography and imaging for the evaluation of middle cerebral artery atherosclerotic disease

Abstract

Intracranial atherosclerotic disease may constitute the most common cause of ischemic stroke worldwide; yet, in the developed world, imaging research has largely focused on extracranial atherosclerosis. Many studies in populations of Asian, African, and Hispanic descent demonstrate the preponderance of intracranial stenosis compared with carotid stenosis. This review examines the clinical presentations of MCA atherosclerosis and stenosis and the use of noninvasive MR imaging in the assessment of intracranial vasculature. MRA is a well-validated technique that offers great advantage over traditional angiography. Advances in high-resolution MR imaging of MCA stenosis have the potential to yield excellent visualization of plaque. Future developments in high-resolution MR imaging to depict intracranial atherosclerosis are explored in this review; these advances will guide endovascular therapy and the comparison of novel interventions.

Fig 1.

Comprehensive imaging of a patient with recent stroke depicting left MCA stenosis. A−G, DSA (A) confirms contrast-enhanced MRA (B) and volume-reduced TOF MRA (C) findings of severe stenosis within the right MCA in a recently symptomatic patient with small ischemic lesions seen on T2 (D and E) and FLAIR (F and G). MRA (B and C) overestimates the degree of stenosis in this particular case.

Fig 2.

Multicontrast high-resolution MR imaging of a normal MCA. Sagittal high-resolution MR imaging of the MCA in a healthy volunteer demonstrates the ability of multiple sequences to depict the arterial wall and lumen in detail.

Fig 3.

Multispectral high-resolution MR imaging of a symptomatic patient with MCA disease. T2-weighted (A and B), spin-echo inversion recovery (C and D), T1-weighted (E and F), and postgadolinium T1-weighted (G and H) images depict a large eccentric contrast-enhancing plaque within the lumen of a recently symptomatic patient on the ipsilateral side of symptom presentation.