The Utility of Intracranial Plaque Imaging Using 3-Tesla Magnetic Resonance Imaging for Middle Cerebral Artery Atherosclerosis

Middle cerebral artery atherosclerosis often causes severe ischemic stroke. Plaque imaging techniques for extracranial carotid lesions with conventional magnetic resonance imaging are widely used to prevent subsequent stroke. However, the plaque imaging for intracranial atherosclerosis with the conventional magnetic resonance imaging is limited because of the poor imaging quality. We hypothesized that the use of high resolution magnetic resonance imaging might resolve the problem and the acquired image might be useful to estimate intra-cranial plaque component. Therefore, the aim of this study is to clarify the utility of a plaque imaging technique using high-resolution magnetic resonance imaging in patients with middle cerebral artery atherosclerosis. In 6 patients (mean, 62; range, 36-75), plaque imaging using T1- and T2-weighted black blood (BB) methods were performed with a 3 tesla scanner without a contrast medium. In each patient, the ability to identify any plaque characteristic was assessed, and the plaques were evaluated on the basis of their signal intensity. For result, plaque images were obtained with enough quality to evaluate plaque components in 5 patients. In a symptomatic case, the plaque included a high-intensity lesion in the T1-weighted black blood method, and this was considered a vulnerable plaque. The plaques in the other cases were iso-intensity and were considered non vulnerable plaques. In a representative case, sudden cardiac arrest occurred 6 months after the stroke. Unfortunately, transient global ischemia caused a severe cerebral infarction on the side of the untreated MCA stenosis. Our results showed that intracranial plaque imaging is useful to estimate plaque histology. In future, this method will be helpful to determine the optimal treatment, including endovascular surgery, for these patients.