Preliminary application of susceptibility weighted imaging in meningiomas

Abstract

Objective To evaluate the preliminary application of susceptibility weighted imaging (SWI) in meningiomas. Methods Fifty meningioma patients, treated at Department of Neurosurgery of Nanjing Brain Hospital Affiliated to Nanjing Medical University between October 2015 and February 2018, were retrospectively enrolled into this study. All cases underwent brain CT, MRI and SWI scans preoperatively, and the minimum intensity projection (mIP) was obtained through processing basic SWI images by software. Compared with MRI and CT, intratumoral microhemorrhage, calcification and drainage vein in meningioma were analyzed in mIP and filtered phase imaging. Pathological examination was carried out after operation. Further comparative analysis was accomplished between microhemorrhagic group and non-microhemorrhagic group in imaging features and pathological indexes. Results Among the 50 meningioma patients examined by SWI, 7 (14%) had 24 intratumoral microhemorrhages; 24 (48%) had 47 intratumoral calcifications, including 31 calcifications that were consistent with CT and 16 which were not detected by CT; 16 (32%) clearly showed dominant draining veins originating from the tumor itself, consisting of 11 without peritumoral edema and 5 with peritumoral edema. The patients without peritumoral edema were more likely to form drainage veins than those with peritumoral edema [61%(11/18) vs. 16% (5/32), P=0.001]. All 50 patients were pathologically confirmed to have WHO Grade Ⅰ meningiomas. The edema index (EI), maximum edema width and Ki67 in the microhemorrhagic group were significant higher than those in non-microhemorrhagic group (all P 0.05). Conclusions Intratumoral microhemorrhage, microcalcification and drainage vein can be detected by SWI. Intratumoral hemorrhages infrequently occur in WHO Grade Ⅰ meningiomas. Microhemorrhagic meningiomas have higher Ki67 and more serious peritumoral edema than non-hemorrhagic ones. The efferent draining vein from meningioma itself may alleviate the formation of peritumoral edema. Key words: Meningioma; Calcinosis; Susceptibility weighted imaging; Microhemorrhage; Vein