Abstract 142: Quantitative Susceptibility Mapping and Vessel Wall Imaging as Screening Tool to Detect Microbleed in Sentinel Headache
Objective: Imaging via MR-quantitative susceptibility mapping (QSM) can identify reliably microbleeds (MBs) associated with intracranial aneurysms (IAs) in subjects presenting with severe headache suggestive of sentinel headache (SH) preceding subarachnoid hemorrhage. However, its use is limited due to associated skull base bonny artifact. Vessel wall imaging (VWI) is not limited by bonny artifact and therefore could be an alternative to QSM in detecting MBs. The purpose of this study is to examine the correlation between QSM and the MR-VWI in detecting MBs associated with severe headache suggestive of SH. Methods: We performed a prospective single-center study of subjects with unruptured IAs with initial presentation of headaches. All subjects underwent evaluation using 3T-MRI protocol which included MRA, QSM, and pre- and post-contrast VWI of the IAs. Presence/absence of MBs detected by QSM was correlated with aneurysm wall enhancement (AWE) on MR-VWI. Results: In the interval of November 2017 to June 2019, a total of 40 subjects harboring 51 unruptured IAs were enrolled in the study. MBs and AWE were detected in 12 (23.5%) and 22 (43.1%) IAs, respectively. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of QSM detecting MBs associated with recent/remote SH was 100% for all, respectively. The sensitivity, specificity, PPV, and NPV of AWE on VWI for detecting MBs confirmed by QSM was 91.7%, 71.8%, 50%, and 96.6%, respectively. Conclusions: The combination of imaging findings of MR-VWI and QSM can be used reliably for detection of MBs in subjects with IAs whose presentation is suggestive of SH. If proven in larger cohort, this could eliminate the need for lumbar puncture to screen for SH in subjects with IAs presenting to the emergency department with headaches.