Abstract 94: Ultra-Fast Performance and Yield of a High-Resolution CT With Head and Neck CT Angiography on a Mobile Stroke Unit

Abstract

Background: MSU’s are capable of ultra-early treatment of acute stroke patients in the field. We tested field use of a high-resolution CT and CT-angiography on our MSU. Methods: We designed and implemented the first of its kind MSU equipped with a 16 slice CT scanner (24-row adaptive detector array, fixed 70 cm gantry, auto-injection system, Somatom Scope, Siemens), led by stroke fellowship trained MDs or ANVP-board certified nurse practitioners without telemedicine support. Head/neck CTA was performed on all suspected stroke patients immediately following noncontrast CT. The MSU is embedded within local Fire/EMS and is activated by 911, or by on-scene medics 14 days/month. Transport and drug re-stock agreements were developed with Comprehensive, Primary, and CSC-Capable (CSC-cap) competing stroke centers. Results: Of 420 activations in the first year, our MSU transported a total 206 patients: 127 (62%) strokes and 79 (38%) stroke mimics. In all 127 acute stroke patients (68±16 years, 58% women, 65% African American, 34% White, 1% Hispanic), median CT/CTA completion time, from start of scan, to images ready for diagnostic viewing, was 3.5 minutes (IQR 3-4). Diagnosis was 15 (12%) hemorrhages, 12 (9%) suspected TIA, 100 (79%) acute ischemic stroke (AIS). AIS median NIHSS was 9, IQR 7-17. IV-tPA treatment rate was 38% with median scene arrival to bolus time of 13 min, IQR 11-16. Large vessel occlusion (LVO) was found in 30% of ischemic strokes. No patients required repeat imaging on arrival due to image quality, and 100% were accurately triaged to CSC, PSC, or CSC-cap hospitals without the need for subsequent transfer. Conclusions: MSUs can effectively operate a high-resolution automated CT similar to in-hospital radiology settings. The addition of head/neck CTA in the field yields a high rate of LVO detection supporting definitive prehospital triage to Comprehensive Stroke Centers.

Improving Outcomes After Stroke: From Stroke Units to Mobile Stroke Units

“…5 , 6 Furthermore, MSUs can produce shorter times to mechanical thrombectomy when computed tomography angiography is performed in the field, along with full emergency department bypass. 7 However, current MSU coverage is still limited by driving distances, times of operation, and by the worldwide availability limited to only 27 cities. As our experience with MSU grows, one might envision different priorities given to MSUs varying by country, hospital systems, geography, and rural versus urban settings dependent on how developed are other components of stroke care systems.…”