ABSTRACT NUMBER: ESOC2026A1503 UTILITY OF THE SPOT SIGN ON MULTIPHASE CT ANGIOGRAPHY FOR PREDICTION OF HEMATOMA EXPANSION IN INTRACEREBRAL HEMORRHAGE

Abstract Background and aims In intracerebral hemorrhage (ICH), the CT angiography (CTA) spot sign is a risk factor for hematoma expansion (HE). While most spot sign studies have used single-phase CTA, multiphase CTA (mCTA) is becoming more common. We aimed to investigate the mCTA spot sign’s association with HE in ICH. Methods We included ICH patients admitted to Karolinska University Hospital 2019-22 with non-contrast CT and mCTA on admission and follow-up CT within 72h. Patients were grouped by the phase in which a spot sign first appeared on mCTA. We examined spot sign numbers, volume, and attenuation in each phase, and their changes between phases. Results The spot sign was detected in 88/159 patients (55%). Of these, 51 (58%) appeared in phase 1, 28 (32%) in phase 2, and 9 (10%) in phase 3. HE occurred in 25/51 (49%), 13/28 (46%), and 4/9 (44%) of patients in the three groups respectively, compared to 12/71 (17%) if spot signs appeared. In patients with HE, on their first appearance, spots were larger, had higher attenuation, and were more numerous. On subsequent phases, an increase in spot numbers, total spot volume, and spot attenuation, were also associated with HE. Conclusions Multi-phase CTA uncovered a large group of ICH patients with spot signs appearing only on the second and third phases, at high risk of HE. Initial and final phase spot sign characteristics, and their evolution, were associated with HE. The added information from mCTA compared to single-phase CTA may make it superior for identifying patients at high risk of HE. Conflict of interest All authors: Nothing to disclose. Figure 1 - belongs to Conclusions