Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China.
Department of Medical Imaging, Xuzhou Medical University, Xuzhou, China.
Cerebrovasc Dis. 2020;49(6):575-582. doi: 10.1159/000509072. Epub 2020 Nov 11.
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.
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.
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.
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%.
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.
在急性缺血性脑卒中患者中，弥散加权成像（DWI）体积是不良预后的独立预测因素，也是溶栓治疗的排除标准。为了克服传统测量方法繁琐且耗时的缺点，提出了一种简化直径法（ABC/2、正交直径[OD]和最大直径[MD]）来替代该方法，但准确性仍有待确定。
本研究旨在明确自动化软件测量的 DWI 梗死体积（Vol-DWI）中基于直径的估计的可靠性和可重复性。
回顾性分析了 316 例在金陵医院发病 72 h 内接受 MRI 检查的急性缺血性脑卒中患者的数据。通过脑梗死的位置（皮质、白质和深部灰质核、联合）和体积（<70 和>70 mL）进行亚组分析。采用 Spearman 秩相关、Wilcoxon 符号秩检验和 Bland-Altman 图来确定直径法与 Vol-DWI 之间的关系和一致性。通过生成受试者工作特征（ROC）曲线确定 OD 和 MD 截断值，以指示梗死面积>15、70 和 100 mL。采用组内相关系数和 Bland-Altman 图评估观察者间的可靠性。
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）。用 ABC/2 公式测量的梗死体积明显低于用 Vol-DWI 测量的体积（Wilcoxon 符号秩检验，z = 6.476，p<0.001）。Bland-Altman 图显示，体积<70 mL 组、白质和深部灰质核组的一致性优于其他亚组。对于梗死体积>15、70 和 100 mL，MD 的截断值分别为 5、6.9 和 8.4 cm，OD 的截断值分别为 12.47、26.4 和 36.4 cm2，敏感性和特异性均>90%。
MD 方法在估计梗死体积方面具有快速、出色的观察者间可靠性，OD 和 MD 方法均可通过阈值评估快速筛选适合再通治疗的患者并预测不良预后。
