Abstract WP267: Impact of Arterial Spin Labeling (ASL) on Etiological Work-up of Adult Spontaneous Intracerebral Hemorrhage (ICH)

Background&Purpose: Macrovascular lesions represent a small but clinically significant cause of spontaneous ICH, disproportionately affecting younger individuals. Accurate etiological work up is critical in guiding appropriate secondary prevention. ASL, a non-contrast MRI perfusion technique, has demonstrated strong diagnostic performance in pediatric ICH but has not been widely validated in the adult population. We evaluate the impact of ASL implementation on the detection of culprit arteriovenous shunts (arteriovenous malformation and dural arteriovenous fistulas) and subsequent DSA practices at a single comprehensive stroke center. Methods: Patients with spontaneous intraparenchymal and/or intraventricular hemorrhage enrolled in a prospective registry were retrospectively included if both CT angiography (CTA) and MRI were obtained during the initial diagnostic work up. Patients were divided into the pre-ASL group if admitted prior to the implementation of ASL (2006-2012), or the post-ASL group if admitted after the implementation of ASL (2022-2023). Detection of shunting lesions was compared between CTA and MRI, as well as DSA, if performed. Results: The pre-ASL group (n=110) and the post-ASL group (n=82) demonstrated similar baseline characteristics. In the pre- and post-ASL groups, culprit arteriovenous shunts were diagnosed at similar rates of 8.1% and 11% ( p = 0.509 ), respectively; CTA yielded similar detection rates of 6.4% vs 8.5% ( p = 0.567 ); MRI detection rate increased from 5.5% vs 11% ( p = 0.159 ), though did not reach statical significance; DSAs were recommended less often, in 42% vs 23% of cases ( p = 0.007) and were associated with a higher rate of positivity in the post-ASL group, 47.4%, compared to 17.4% in the pre-ASL group ( p = 0.012 ) . Conclusions: These findings suggest that ASL imaging can be used as an effective adjunct to standard imaging techniques in the etiological work up for spontaneous ICH for the detection of arteriovenous shunting lesions. Future directions include comparing detection rates of arteriovenous shunting lesions and DSA practices in patients who underwent either CTA or MRI alone.