SELECT-CT: Symptom Evaluation, Lesion Estimation, and Curated Triage to CT-A Simple Algorithm to Select the Right...

The intended purpose of multimodal Code Stroke CT (CSCT) is to rapidly identify patients with acute ischemic stroke who are likely to benefit from mechanical thrombectomy. This study aimed to evaluate a new clinical algorithm for reliably identifying thrombectomy candidates while reducing the number of CSCT scans that are currently inundating radiology services.

This retrospective cohort study was performed on consecutive patients who underwent mechanical thrombectomy at a comprehensive stroke center during a 2-year period. The Symptom Evaluation, Lesion Estimation, and Clinical Triage for CT (SELECT-CT) algorithm, ie, an NIHSS score threshold of ≥2 and/or any posterior circulation or disabling symptoms, was applied to identify patients with large and distal medium vessel occlusions who may benefit from thrombectomy. The performance of SELECT-CT and 6 different NIHSS score thresholds (from ≥1 to ≥6) for reducing CSCT scan numbers, while correctly identifying patients treated with thrombectomy, was also assessed.

During the study period 4921 patients had CSCT scans, yielding a 5% thrombectomy rate. Of 240 patients (median age 73; 54.6% male) who underwent thrombectomy, the NIHSS score ≥6 captured only 198 (83%), including 151 of 166 patients (91%) with an anterior circulation large vessel occlusion. Conversely, the threshold of ≥2 alone captured 229 of 240 (95%) thrombectomy patients. Using SELECT-CT, performance improved to correct identification of 232 of 240 (97%) thrombectomy patients, including all who should be treated based on current evidence. Applying NIHSS score thresholds of ≥6 and ≥2 for patient triage to CSCT reduced scan volume by 76% and 47%, respectively. The more cautious and nuanced approach using SELECT-CT achieved a 30% reduction in scan numbers.

The SELECT-CT algorithm can reduce CSCT scan workload while still identifying patients who should be treated with thrombectomy.