Clinical Uncertainty in Large Vessel Occlusion Ischemic Stroke: Does Automated Perfusion Imaging Make a Difference? An Intrarater and Interrater Agreement Study

Abstract

Background

Guidelines recommend the use of perfusion computed tomography (CT) to identify emergent large vessel ischemic stroke (ELVIS) patients who are likely to benefit from endovascular thrombectomy (EVT) if they present within 6-24 hour (late window) of stroke onset. We aim to determine if the interrater and intrarater reliability among physicians when recommending EVT is significantly different when perfusion CT or non-perfusion CT is reviewed.

Methods

A total of 30 non-consecutive patients were selected from our institutional database comprising 3144 cranial CT scans (January 2018-August 2022) performed for acute stroke symptoms. The clinical and radiologic data of the 30 patients were presented in random order to a group of 29 physicians in two separate sessions at least three weeks apart. In each session, the physicians evaluated each patient once with automated perfusion images and once without. We used non-overlapping 95% confidence intervals and difference in agreement classification as criteria to suggest a difference between the Gwet AC1 statistics (κG).

Results

Twenty-nine raters successfully completed the first round of surveys, with all but one of them also completing the second. The interrater (κG) agreement amonth 29 raters is similar with non-perfusion CT neuroimaging compared to perfusion CT neuroimaging (κG = 0.487; 95% CI 0.327,0.647 and κG =0.552; 95% CI 0.430,0.675). The 95% confidence intervals overlapped and both κG signify moderate agreement. The intrarater agreement κG had overlapping 95% confidence intervals for all 28 raters. κG was either substantial or excellent (0.81-1) for 71.4% (20/28) of patients in both groups.

Conclusions

Our findings suggest that automated perfusion images and quantitative values that are present in the perfusion CT neuroimaging but not in non-perfusion CT neuroimaging do not significantly affect the reliability of the decisions made by physicians on EVT for late window ELVIS patients.