Background: In acute ischemic stroke, diffusion-weighted imaging (DWI) volume is an independent predictive factor of poor outcome and an exclusion criterion for thrombolytic treatment. A simplified diameters method (ABC/2, orthogonal diameter [OD], and the maximum diameter [MD]) was proposed to replace the conventional measuring method and overcome the tedious and time-consuming defects, but its accuracy remains to be determined. Objective: The objective of this study is to clarify the reliability and reproducibility of the diameter-based estimations in the infarct volume in DWI (Vol-DWI) measured by automated software. Methods: Data of 316 patients with acute ischemic stroke who underwent MRI within 72 h at Jinling Hospital were retrospectively reviewed. Subgroup analysis by the location (cortex, white matter and deep gray nuclei, and combined) and volume (<70 and >70 mL) of cerebral infarction was evaluated. Relationship and consistency between the diameters methods and Vol-DWI were determined using Spearman rank correlation, Wilcoxon signed-rank test, and Bland-Altman plots. The OD and MD thresholds indicating infarct size >15, 70, and 100 mL were determined by generating receiver-operating characteristic (ROC) curves. Interobserver reliability was established using intraclass correlation coefficient and Bland-Altman plot. Results: There was a strong positive correlation between the diameters and the Vol-DWI (ABC/2: r = 0.992, OD: r = 0.984, MD: r = 0.970, p < 0.001). Infarct volumes measured using the ABC/2 formula were significantly lower than those measured with Vol-DWI (Wilcoxon signed-rank test, z = 6.476, p < 0.001). Bland-Altman plot showed that the agreement of the volume <70 mL group, and white matter and deep gray nuclei groups was better than that of the other subgroups. For infarct volumes >15, 70, and 100 mL, the cutoff value for the MD was identified at 5, 6.9, and 8.4 cm, and the OD was identified at 12.47, 26.4, and 36.4 cm2, respectively, with a sensitivity and specificity >90%. Conclusions: The MD method was the best for achieving a rapid and excellent interobserver reliability for estimating infarct volume. Both OD and MD methods can quickly screen patients suitable for recanalization treatment and predict poor prognosis through threshold evaluation.

中文翻译：

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直径法在磁共振弥散加权成像中快速测定急性梗死体积的可靠性和重现性

背景：在急性缺血性卒中中，弥散加权成像 (DWI) 体积是预后不良的独立预测因素和溶栓治疗的排除标准。提出了一种简化的直径法（ABC/2、正交直径[OD]和最大直径[MD]）来代替传统的测量方法，克服繁琐耗时的缺陷，但其精度仍有待确定。目的：本研究的目的是阐明通过自动化软件测量的 DWI 梗死体积（Vol-DWI）中基于直径的估计的可靠性和可重复性。方法：回顾性分析金陵医院72 h内行MRI检查的316例急性缺血性脑卒中患者资料。按位置（皮层、白质和深灰核、和合并）和脑梗塞的体积（<70 和 >70 mL）进行了评估。使用 Spearman 等级相关、Wilcoxon 符号等级检验和 Bland-Altman 图确定直径方法和 Vol-DWI 之间的关系和一致性。OD 和 MD 阈值表明梗死面积 >15、70 和 100 mL，通过生成受试者工作特征 (ROC) 曲线来确定。使用组内相关系数和 Bland-Altman 图建立观察者间的可靠性。结果：直径与 Vol-DWI 之间存在很强的正相关（ABC/2：r = 0.992，OD：r = 0.984，MD：r = 0.970，p < 0.001）。使用 ABC/2 公式测量的梗死体积显着低于使用 Vol-DWI 测量的梗死体积（Wilcoxon 符号秩检验，z = 6.476，p < 0.001）。Bland-Altman图显示体积<70 mL组与白质和深灰核组的一致性优于其他亚组。对于 >15、70 和 100 mL 的梗死体积，MD 的截止值确定为 5、6.9 和 8.4 cm，OD 确定为 12.47、26.4 和 36.4 cm2，分别具有敏感性和特异性> 90%。结论：MD 方法是实现估计梗塞体积的快速且出色的观察者间可靠性的最佳方法。OD 和 MD 方法都可以快速筛选适合再通治疗的患者，并通过阈值评估预测不良预后。MD 的截止值分别为 5、6.9 和 8.4 cm，OD 分别为 12.47、26.4 和 36.4 cm2，灵敏度和特异性 >90%。结论：MD 方法是实现估计梗塞体积的快速且出色的观察者间可靠性的最佳方法。OD 和 MD 方法都可以快速筛选适合再通治疗的患者，并通过阈值评估预测不良预后。MD 的截止值分别为 5、6.9 和 8.4 cm，OD 分别为 12.47、26.4 和 36.4 cm2，灵敏度和特异性 >90%。结论：MD 方法是实现估计梗塞体积的快速且出色的观察者间可靠性的最佳方法。OD 和 MD 方法都可以快速筛选适合再通治疗的患者，并通过阈值评估预测不良预后。