Exclusion of Isolated Cortical Swelling Can Increase Efficacy of Baseline Alberta Stroke Program Early CT Score in the Prediction of Prognosis in Acute Ischemic Stroke Patients Treated with Thrombolysis

Validation of two automated ASPECTS software on non-contrast computed tomography scans of patients with acute ischemic stroke

Purpose

The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) was designed for semi-quantitative assessment of early ischemic changes on non-contrast computed tomography (NCCT) for acute ischemic stroke (AIS). We evaluated two automated ASPECTS software in comparison with reference standard.

Methods

NCCT of 276 AIS patients were retrospectively reviewed (March 2018–June 2020). A three-radiologist consensus for ASPECTS was used as reference standard. Imaging data from both baseline and follow-up were evaluated for reference standard. Automated ASPECTS were calculated from baseline NCCT with 1-mm and 5-mm slice thickness, respectively. Agreement between automated ASPECTS and reference standard was assessed using intra-class correlation coefficient (ICC). Correlation of automated ASPECTS with baseline stroke severity (NIHSS) and follow-up ASPECTS were evaluated using Spearman correlation analysis.

Results

In score-based analysis, automated ASPECTS calculated from 5-mm slice thickness images agreed well with reference standard (software A: ICC = 0.77; software B: ICC = 0.65). Bland–Altman analysis revealed that the mean differences between automated ASPECTS and reference standard were ≤ 0.6. In region-based analysis, automated ASPECTS derived from 5-mm slice thickness images by software A showed higher sensitivity (0.60 vs. 0.54), lower specificity (0.91 vs. 0.94), and higher AUC (0.76 vs. 0.74) than those using 1-mm slice thickness images (p < 0.05). Automated ASPECTS derived from 5-mm slice thickness images by software B showed higher sensitivity (0.56 vs. 0.51), higher specificity (0.87 vs. 0.81), higher accuracy (0.80 vs. 0.73), and higher AUC (0.71 vs. 0.66) than those using 1-mm slice thickness images (p < 0.05). Automated ASPECTS were significantly associated with baseline NIHSS and follow-up ASPECTS.

Conclusion

Automated ASPECTS showed good reliability and 5 mm was the optimal slice thickness.

Short-term Montreal Cognitive Assessment predicts functional outcome after endovascular therapy

Background

The previous studies have shown that cognition in patients 4–8 weeks after stroke can predict early functional outcomes after stroke. The analyses of data from the REVASCAT trial proved that stent thrombectomy improves post-morbid wiring test outcomes in patients with AIS compared with drug therapy. However, few studies focus on the relationship between cognitive impairment and functional outcomes in patients undergoing endovascular treatment.

Methods

A total of 647 participants registered from stroke centers. Stroke severity was evaluated by National Institutes of Health stroke scale (NIHSS). The functional status was estimated by modified Rankin scale (mRS). The cognitive impairment was assessed by trained neurologists at 14 (±4) and 90 (±7) days after stroke onset using the Montreal Cognitive Assessment (MoCA). A MoCA score of less than 26 was considered post-stroke cognitive impairment (PSCI).

Results

A total of 120 Patients who underwent endovascular therapy were included. The PSCI group had higher levels of age, men, educational status, atrial fibrillation, smoking, alcoholism, Alberta Stroke Program Early CT (ASPECT) score of the anterior circulation, and OTP time than the non-PSCI group (p < 0.05). In contrast, the 14-day MoCA score, 14-day NIHSS score, 3-month MoCA score, 3-month NIHSS score, 3-month mRS score, and 3-month EQ5D score were lower in those PSCI patients. The risk predictors of PSCI were age, sex, educational level, atrial fibrillation, smoking, alcoholism, ASPECT Score (anterior circulation), 14-day MoCA score, and 14-day NIHSS score. There were strong relationships between 3-month NIHSS and MoCA (r = –0.483, p < 0.001). Receiver operating characteristic (ROC) curve indicated that 14-day MoCA score, memory, abstraction, visuospatial/executive functions, attention, and language, played a significant role to predict PSCI [area under the curve (AUC) > 0.7]. It had predictive value for the 14-day visuospatial/executive functions to predict 3-month functional outcomes.

Conclusion

Early application of the MoCA in different cognitive regions could predict the PSCI and future functional outcomes, which is necessary to screen high-risk patients with poor prognosis and conduct an early intervention.

ASPECTS CT in Acute Ischemia: Review of Current Data

The Alberta Stroke Program Early CT score (ASPECTS) is a 10-point semiquantitative topographic scoring system developed for the assessment of early ischemic changes (EICs) on noncontrast-enhanced computed tomography (NCCT) in patients with acute ischemic stroke involving the middle cerebral artery (MCA) territory. One point is subtracted from a total score of 10, if an EIC is present in any part of each of the ASPECTS regions. Higher ASPECTS has been associated with better outcomes and a lower risk of symptomatic intracerebral hemorrhage. To date, there are still controversies regarding the utility of ASPECTS for selecting patients for intravenous and intra-arterial therapies. This article provides a comprehensive review regarding methodology, limitations, and interobserver reproducibility of ASPECTS, as well as application of ASPECTS in clinical care. The focus of this review is ASPECTS evaluation on NCCT. The application of ASPECTS on multimodal computed tomography and magnetic resonance imaging (MRI) is briefly described.