Departments of Clinical Neurosciences, Calgary Stroke Program, Cumming School of Medicine, University of Calgary, Calgary, Canada.
Department of Medical Imaging, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Brno, Czech Republic.
Neuroradiology. 2022 Jun;64(6):1165-1173. doi: 10.1007/s00234-021-02855-z. Epub 2021 Nov 23.
Infarct lesion volume (ILV) may serve as an imaging biomarker for clinical outcomes in the early post-treatment stage in patients with acute ischemic stroke. The aim of this study was to evaluate the inter- and intra-rater reliability of manual segmentation of ILV on follow-up non-contrast CT (NCCT) scans.
Fifty patients from the Prove-IT study were randomly selected for this analysis. Three raters manually segmented ILV on 24-h NCCT scans, slice by slice, three times. The reference standard for ILV was generated by the Simultaneous Truth And Performance Level estimation (STAPLE) algorithm. Intra- and inter-rater reliability was evaluated, using metrics of intraclass correlation coefficient (ICC) regarding lesion volume and the Dice similarity coefficient (DSC).
Median age of the 50 subjects included was 74.5 years (interquartile range [IQR] 67-80), 54% were women, median baseline National Institutes of Health Stroke Scale was 18 (IQR 11-22), median baseline ASPECTS was 9 (IQR 6-10). The mean reference standard ILV was 92.5 ml (standard deviation (SD) ± 100.9 ml). The manually segmented ILV ranged from 88.2 ± 91.5 to 135.5 ± 119.9 ml (means referring to the variation between readers, SD within readers). Inter-rater ICC was 0.83 (95%CI: 0.76-0.88); intra-rater ICC ranged from 0.85 (95%CI: 0.72-0.92) to 0.95 (95%CI: 0.91-0.97). The mean DSC among the three readers ranged from 65.5 ± 22.9 to 76.4 ± 17.1% and the mean overall DSC was 72.8 ± 23.0%.
Manual ILV measurements on follow-up CT scans are reliable to measure the radiological outcome despite some variability.
在急性缺血性脑卒中患者治疗后早期，梗死病灶体积（ILV）可能作为一种影像学生物标志物，用于预测临床结局。本研究旨在评估在 24 小时非对比 CT（NCCT）扫描上对 ILV 进行手动分割的观察者内和观察者间的可靠性。
本研究从 Prove-IT 研究中随机选取了 50 名患者进行分析。三名观察者分别在 24 小时 NCCT 扫描上逐片手动分割 ILV，共进行三次。ILV 的参考标准由同时真实和性能水平估计（STAPLE）算法生成。使用基于病变体积的组内相关系数（ICC）和 Dice 相似系数（DSC）评估观察者内和观察者间的可靠性。
50 名受试者的中位年龄为 74.5 岁（四分位距[IQR]67-80），54%为女性，中位基线国立卫生研究院卒中量表（NIHSS）为 18（IQR11-22），中位基线 ASPECTS 为 9（IQR6-10）。参考标准 ILV 的平均值为 92.5ml（标准差[SD]±100.9ml）。手动分割的 ILV 范围为 88.2±91.5 至 135.5±119.9ml（表示读者间的变化，读者内的 SD）。观察者间 ICC 为 0.83（95%CI：0.76-0.88）；观察者内 ICC 范围为 0.85（95%CI：0.72-0.92）至 0.95（95%CI：0.91-0.97）。三名读者的平均 DSC 范围为 65.5±22.9 至 76.4±17.1%，平均总体 DSC 为 72.8±23.0%。
尽管存在一定的变异性，但在随访 CT 扫描上对 ILV 进行手动测量仍可可靠地测量影像学结果。
