Abstract：
BACKGROUND: Posterior circulation Acute Stroke Prognosis Early Computed Tomography Scores (pc-ASPECTS) is a rapid method of measuring early ischemic changes. However, there was no agreement study about pc-ASPECTS.
OBJECTIVE: The purpose of the present study was to evaluate the agreement on pc-ASPECTS based on non-contrast CT (NCCT) and CT angiography (CTA) source images in patients with acute basilar artery occlusion (BAO).
METHODS: We prospectively enrolled consecutive patients with acute BAO from January 2022 to August 2022 at the First Affiliated Hospital of University of Science and Technology of China. The NCCT and CTA were scored independently by 15 raters during 2 different reading sessions at least 3 weeks apart. The pc-ASPECTS based on NCCT and CTA were analyzed on the full scale or were dichotomized (0-6 vs. 7-10, 0-7 vs. 8-10, and 0-8 vs. 9-10). The level of agreement was measured using Fleiss κ statistics.
RESULTS: The median (IQR) CT-based pc-ASPECTS was 8 (6.75-9). The interrater agreement for CT-based pc-ASPECTS (κ = 0.133 [0.132-0.133]) and CTA-based pc-ASPECTS (κ = 0.204 [0.203-0.204]) was slight for all raters. Dichotomizations obtaining the highest concordance for the CT-based pc-ASPECTS (0-6 vs. 7-10) and the CTA-based pc-ASPECTS (0-8 vs. 9-10) failed to increase the interrater agreement to a substantial level (κ = 0.350 [0.348-0.351] and 0.396 [0.395-0.398], respectively). Intrarater agreement for global CT-based pc-ASPECTS was less than substantial for the 14/15 raters and reached the level of substantial for the 3/15 raters with dichotomization.
CONCLUSIONS: Agreement between clinicians assessing CT-based and CTA-based pc-ASPECTS cannot be sufficient to make reproducible clinical decisions and assessments. The dichotomization failed to improve interrater and intrarater agreement to the level of substantial.
OBJECTIVE: The purpose of the present study was to evaluate the agreement on pc-ASPECTS based on non-contrast CT (NCCT) and CT angiography (CTA) source images in patients with acute basilar artery occlusion (BAO).
METHODS: We prospectively enrolled consecutive patients with acute BAO from January 2022 to August 2022 at the First Affiliated Hospital of University of Science and Technology of China. The NCCT and CTA were scored independently by 15 raters during 2 different reading sessions at least 3 weeks apart. The pc-ASPECTS based on NCCT and CTA were analyzed on the full scale or were dichotomized (0-6 vs. 7-10, 0-7 vs. 8-10, and 0-8 vs. 9-10). The level of agreement was measured using Fleiss κ statistics.
RESULTS: The median (IQR) CT-based pc-ASPECTS was 8 (6.75-9). The interrater agreement for CT-based pc-ASPECTS (κ = 0.133 [0.132-0.133]) and CTA-based pc-ASPECTS (κ = 0.204 [0.203-0.204]) was slight for all raters. Dichotomizations obtaining the highest concordance for the CT-based pc-ASPECTS (0-6 vs. 7-10) and the CTA-based pc-ASPECTS (0-8 vs. 9-10) failed to increase the interrater agreement to a substantial level (κ = 0.350 [0.348-0.351] and 0.396 [0.395-0.398], respectively). Intrarater agreement for global CT-based pc-ASPECTS was less than substantial for the 14/15 raters and reached the level of substantial for the 3/15 raters with dichotomization.
CONCLUSIONS: Agreement between clinicians assessing CT-based and CTA-based pc-ASPECTS cannot be sufficient to make reproducible clinical decisions and assessments. The dichotomization failed to improve interrater and intrarater agreement to the level of substantial.
摘要：
目的：本研究的目的是评估基于非对比CT（NCCT）和CT血管造影（CTA）源图像的PC-ASPERTS（后循环急性卒中预后早期计算机断层扫描评分）的一致性急性基底动脉闭塞（BAO）患者。
方法：我们前瞻性纳入了中国科学技术大学附属第一医院2022年1月至2022年8月收治的连续急性BAO患者。NCCT和CTA由15名评估者在两次不同的阅读期间至少间隔3周进行独立评分。对基于NCCT和CTA的pc-ASPECTS进行全尺寸分析或进行二分法（0-6对7-10，0-7对8-10和0-8对9-10）。一致性水平是使用FleissκStatistics测量的。
结果：以CT为基础的pc-ASPECTS的中位数（IQR）为8（6.75-9）。对于所有评估者，基于CT的pc-ASPECTS（κ=0.133[0.132-0.133]）和基于CTA的pc-ASPECTS（κ=0.204[0.203-0.204]）的评估者之间的协议很小。对于基于CT的pc-ASPECTS（0-6对7-10）和基于CTA的pc-ASPECTS（0-8对9-10）获得最高一致性的二分法未能将评分者之间的一致性提高到实质性水平（κ=0.350[0.348-0.351]和0.396[0.395-0.398]，分别)。对于14/15的评估者，基于CT的全球pc-ASPECTS的内部协议不那么重要，而对于具有二分法的3/15评估者则达到了实质性水平。
结论：临床医生评估基于CT和基于CTA的pc-ASPECTS之间的协议不足以做出可重复的临床决策和评估。二分法未能将评估者之间和内部的协议提高到实质性水平。
方法：我们前瞻性纳入了中国科学技术大学附属第一医院2022年1月至2022年8月收治的连续急性BAO患者。NCCT和CTA由15名评估者在两次不同的阅读期间至少间隔3周进行独立评分。对基于NCCT和CTA的pc-ASPECTS进行全尺寸分析或进行二分法（0-6对7-10，0-7对8-10和0-8对9-10）。一致性水平是使用FleissκStatistics测量的。
结果：以CT为基础的pc-ASPECTS的中位数（IQR）为8（6.75-9）。对于所有评估者，基于CT的pc-ASPECTS（κ=0.133[0.132-0.133]）和基于CTA的pc-ASPECTS（κ=0.204[0.203-0.204]）的评估者之间的协议很小。对于基于CT的pc-ASPECTS（0-6对7-10）和基于CTA的pc-ASPECTS（0-8对9-10）获得最高一致性的二分法未能将评分者之间的一致性提高到实质性水平（κ=0.350[0.348-0.351]和0.396[0.395-0.398]，分别)。对于14/15的评估者，基于CT的全球pc-ASPECTS的内部协议不那么重要，而对于具有二分法的3/15评估者则达到了实质性水平。
结论：临床医生评估基于CT和基于CTA的pc-ASPECTS之间的协议不足以做出可重复的临床决策和评估。二分法未能将评估者之间和内部的协议提高到实质性水平。
