Evaluate the follow-up effect of drug treatment for middle cerebral artery atherosclerotic plaques using high resolution MRI

Objective To explore the value of 3.0 T high resolution MRI (HR-MRI) in the follow-up of drug treatment in acute and non-acute ischemic stroke caused by middle cerebral artery (MCA) plaque. Methods The perspective study enrolled patients with ischemic stroke caused by MCA stenosis from October 2012 to October 2015 in the department of Neurology and Neurosurgery of Changhai Hospital Affiliated to Naval Medical University. All the patients underwent HR-MRI and then were divided into acute and non-acute stroke groups according to the intervels of the last symptom onset to the time of HR-MRI examination. All patients were informed consent to receive antiplatelet drug and intensive lipid therapy and followed up with HR-MRI. The HR-MRI sequence including T2WI, T1WI and contrast-enhanced T1WI of vessel wall, and T2WI and DWI of brain were routinely performed. T-test of paired samples was used to evaluate the changes of stenosis rate of vascular lumen, plaque enhancement degree, plaque volume and plaque burden on HR-MRI, and the NIHSS score of nervous system and blood biochemical indicators of the patients before and after treatment. Chi square test was used to compare the difference in ischemic event recurrcence between the acute and the non-acute stroke group. Results A total of 31 acute stroke patients and 20 non-acute stroke patients were enrolled in the study. The mean follow-up time of acute stroke group was (671.71±522.86) days. Compare with the baseline, the stenosis rate of vascular lumen (P=0.039), plaque enhancement degree (P 0.05). There were no significant changes in NIHSS score of nervous system, TC, triglyceride (TG) and LDL-C (P>0.05), however the high density lipoprotein cholesterol (HDL-C) was significantly increased than that in the baseline (P=0.02). During the follow-up period, no new cerebral infarction was found in the DWI images of the two groups. Six patients had transient ischemic attack (TIA) recurrence in the acute stroke group and 5 patients in the non-acute stroke group, there was no significant difference between both groups(χ2=0.229, P= 0.632). Conclusion HR-MRI can be used as an important evaluation method for the follow-up of MCA atherosclerotic plaque therapy. After antiplatelet therapy and intensive lipid-lowering therapy, the plaque volume and burden of MCA offending plaque, and plaque enhancement decreased in acute stroke patients but there was no significant change in non-acute patients. Key words: Atherosclerosis; Magnetic resonance imaging; Stroke; Follow-up studies