Division of Neuroradiology and Interventional Neuroradiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, Gray 241, Boston, MA 02114, USA.
Radiology. 2012 Feb;262(2):593-604. doi: 10.1148/radiol.11110896. Epub 2011 Dec 20.
To test whether the relationship between acute ischemic infarct size on concurrent computed tomographic (CT) angiography source images and diffusion-weighted (DW) magnetic resonance images is dependent on the parameters of CT angiography acquisition protocols.
This retrospective study had institutional review board approval, and all records were HIPAA compliant. Data in 100 patients with anterior-circulation acute ischemic stroke and large vessel occlusion who underwent concurrent CT angiography and DW imaging within 9 hours of symptom onset were analyzed. Measured areas of hyperintensity at acute DW imaging were used as the standard of reference for infarct size. Information regarding lesion volumes and CT angiography protocol parameters was collected for each patient. For analysis, patients were divided into two groups on the basis of CT angiography protocol differences (patients in group 1 were imaged with the older, slower protocol). Intermethod agreement for infarct size was evaluated by using the Wilcoxon signed rank test, as well as by using Spearman correlation and Bland-Altman analysis. Multivariate analysis was performed to identify predictors of marked (≥20%) overestimation of infarct size on CT angiography source images.
In group 1 (n=35), median hypoattenuation volumes on CT angiography source images were slightly underestimated compared with DW imaging hyperintensity volumes (33.0 vs 41.6 mL, P=.01; ratio=0.83), with high correlation (ρ=0.91). In group 2 (n=65), median volume on CT angiography source images was much larger than that on DW images (94.8 vs 17.8 mL, P<.0001; ratio=3.5), with poor correlation (ρ=0.49). This overestimation on CT angiography source images would have inappropriately excluded from reperfusion therapy 44.4% or 90.3% of patients eligible according to DW imaging criteria on the basis of a 100-mL absolute threshold or a 20% or greater mismatch threshold, respectively. Atrial fibrillation and shorter time from contrast material injection to image acquisition were independent predictors of marked (≥20%) infarct size overestimation on CT angiography source images.
CT angiography protocol changes designed to speed imaging and optimize arterial opacification are associated with significant overestimation of infarct size on CT angiography source images.
测试在同时进行的计算机断层（CT）血管造影源图像和弥散加权（DW）磁共振图像上急性缺血性梗死面积之间的关系是否依赖于 CT 血管造影采集方案的参数。
本回顾性研究获得了机构审查委员会的批准，所有记录均符合 HIPAA 规定。对 100 例前循环急性缺血性卒中且发病后 9 小时内行同时进行的 CT 血管造影和 DW 成像的大血管闭塞患者的数据进行了分析。在急性 DW 成像上测量的高信号区域被用作梗死面积的标准参考。为每位患者收集了关于病变体积和 CT 血管造影方案参数的信息。基于 CT 血管造影方案差异（组 1 患者采用较旧、较慢的方案进行成像），将患者分为两组。通过 Wilcoxon 符号秩检验评估梗死面积的方法间一致性，以及通过 Spearman 相关分析和 Bland-Altman 分析评估。进行多变量分析以确定 CT 血管造影源图像上明显（≥20%）高估梗死面积的预测因子。
在组 1（n=35）中，CT 血管造影源图像上的低衰减体积与 DW 成像上的高信号体积相比，稍小（33.0 比 41.6 mL，P=.01；比值=0.83），两者相关性很高（ρ=0.91）。在组 2（n=65）中，CT 血管造影源图像上的体积明显大于 DW 图像（94.8 比 17.8 mL，P<.0001；比值=3.5），相关性较差（ρ=0.49）。如果根据 DW 成像标准以 100 mL 的绝对阈值或 20%或更大的不匹配阈值作为标准，该高估会不适当地排除 44.4%或 90.3%的有再灌注治疗适应证的患者。心房颤动和对比剂注射到图像采集之间的时间较短是 CT 血管造影源图像上明显（≥20%）高估梗死面积的独立预测因子。
旨在加快成像和优化动脉显影的 CT 血管造影方案变化与 CT 血管造影源图像上梗死面积的显著高估有关。
