Abstract W P45: High Resolution Images of Perforating Arteries With 7T MRA in Acute Subcortical Infarction

Abstract

Introduction: Patients with acute subcortical infarction show various clinical courses according to the pathology of perforating artery so that the noninvasive and precise neuroradiological evaluation of these arteries is very important for prevention of progression and recurrence of the disease. 7 Tesla (7T) - MRI (Magnetic Resonance Imaging) makes it possible to visualize perforating arteries in a way that would not otherwise be possible using conventional MRI. We attempted to assess perforating arteries and infarct lesions in the lenticulostriate artery (LSA) area using 7T- High resolution MRA (Magnetic Resonance Angiography), and to evaluate the association between image findings and clinical courses of treatment. Method: We included 13 patients (M:F = 7:6, mean age: 65 years old) with acute noncardioembolic stroke in LSA area detected by 1.5-T MRI. 7T MRI was acquired among these patients within 2 weeks after onset to visualize responsible LSA and to measure the volume of infarction by 7T-MRI- 3D-TOF MRA, 3D-FLAIR. We also evaluated the association between these results and the severity of stroke by National Institute of Health Stroke Scale (NIHSS). Results: Perforating arteries in the basal ganglia area were clearly visualized in all patients using 7T MRA. According to the location of occlusion and ischemic lesion, patients were categorized into 3 groups (A, B, and C): Group A - patients with proximal branch occlusion of LSA (2 cases), Group B - patients with occlusion of LSA adjacent to the ischemic lesion (7 cases), Group C - no occlusions (4 cases) in LSA associated with infarction. Significant association between overall infarct volume and NIHSS(r=0.636, p=0.020)was observed, whereas infarct volume of each group was not associated with NIHSS. Clinical outcome were not associated with volume of infarction in all cases(p=0.12). However, there were no patients whose symptoms progressed in Group C. Conclusion: 7 T-MRA can provide a clear visualization of perforating arteries and occluded lesions. It can be a useful and noninvasive diagnostic tool to study clinical prognosis after treatment in acute subcortical infarction.