Abstract Body: Introduction:
Computer Tomography Perfusion (CTP) has become widely implemented into workflow models for adults presenting with acute stroke. However, its utilization in the pediatric/young adult population is not well characterized.

Methods
We queried the RAPID Insights database from 10/05/2018-09/29/2023 for unique patients between 2-25 years with a CTP. Our inclusion criteria required a minimum ischemic core volume (defined as relative cerebral blood flow (rCBF) reduction of 30% less than normal) of >0 cc and a minimum mismatch volume of >/=0 cc. We analyzed age by pre-defined strata: 2-5, 6-11, 12-18, and 19-25 years. Utilization patterns were analyzed using descriptive statistics according to geographic region: Midwest, Northeast, Southeast, Southwest, and West, and by time epochs, defined as Day: 07:00h-14:59h, Evening: 15:00h-22:59h, and Night: 23:00h-06:59h.

Results
There were 2492 unique CTP scans. There was a positive correlation between CTP usage with increasing age, with only 23/2492 (0.9%) of scans performed in the 2-5 year age group, and 1825/2492 (73.2%) scans performed in the 19-25 year age group. 307 (12.3%) cases had large vessel occlusions (LVOs) detected, and 77 (3.1%) had intracerebral hemorrhage (ICH). The ICH group was significantly younger than the total cohort: 18.8+/-5.1 vs 20.0+/-3.9 years (p=0.0085). There was a significantly higher proportion of ICHs detected on weekend days compared to LVOs: 59/77 (76.6%) vs 85/307 (27.7%), p<0.0001. Similar proportions of scans were done during the Day (37.5%) and Evening (43.1%), with only 19.4% of scans performed during the Night. The Northeast and Southeast had the highest number of scans performed per hospital (599/168 and 577/129, respectively) compared to the Southwest which had the lowest (156/49).

Conclusion
This is the largest cohort of CTP studies done in the pediatric/ young adult population for suspected acute cerebral ischemia. Future studies should incorporate clinical indications and perfusion thresholds to advance our limited understanding of CTP use in the pediatric and young adult population.