[Methods for determining the extent of ischemic changes in brain matter in the prognosis of clinical outcome after successful thromboextraction].

Objective: To determine the method of primary assessment of the extent of ischemic changes of the brain matter with the greatest prognostic significance for the clinical outcome of the disease in case of successful thromboextraction (achievement of TICI 2b/3 blood flow).

Material and methods: The retrospective analysis included 90 patients with ischemic stroke in the carotid system, admitted within 0 to 16 hours from the onset of the disease and performed thromboextraction with achieved TICI 2b/3 blood flow. The group with good/satisfactory functional recovery (mRS score 0-3) included 69 patients; the group with poor functional recovery/death (mRS score 4-6) included 21 patients. The study examined the prognostic significance of methods for assessing ischemic changes in native CT images (both by a doctor and using artificial intelligence) and methods for automatic cerebral perfusion analysis.

Results: Based on the ROC analysis results, ROC curves were obtained corresponding to the relationship between the extent of ischemic changes in the brain matter and a good/satisfactory outcome (mRS 0-3). The largest area under the ROC curve was obtained when assessing the volume of brain matter with rCBF <30% (0.861, 95% CI 0.753-0.968, p<0.0005) and the ASPECTS score evaluated retrospectively by an expert-level physician (0.846, 95% CI 0.738-0.953, p<0.0005). When assessing the T_max/rCBF of the mismatch, the area under the ROC curve was 0.794 (95% CI 0.639-0.949, p=0.001); for the eASPECTS score 0.764 (95% CI 0.653-0.874, p<0.0005); for the volume of the brain matter with early CT signs of ischemia 0.751 (95% CI 0.631-0.872, p=0.001); for the ASPECTS score evaluated prospectively by radiologist on duty 0.777 (95% CI 0.667-0.887, p<0.0005); for the volume of the brain matter with T_max >6 s (0.607, 95% CI 0.457-0.757, p=0.213).

Conclusion: The ASPECTS score, eASPECTS, the volume of brain matter with early CT signs of ischemic changes, the volume of brain matter with rCBF <30%, as well as the T_max/rCBF mismatch value predict the outcome of the disease with a high degree of confidence within the timeframe from 0 to 16 hours. The ASPECTS score assessed by an expert doctor and the volume of the brain substance with rCBF <30% had the greatest prognostic value for the functional outcome. The volume with a T_max >6 s had the least predictive value. Methods for assessing brain matter using artificial intelligence algorithms (eASPECTS and volume with early signs of ischemia) showed predictive value for the functional outcome comparable to the ASPECTS score obtained by radiologists on duty in routine practice.