Forbrig Robert, Trumm Christoph G, Reidler Paul, Kunz Wolfgang G, Dimitriadis Konstantinos, Kellert Lars, Rückel Johannes, Liebig Thomas, Stahl Robert
Institute for Diagnostic and Interventional Neuroradiology, LMU University Hospital, LMU Munich, Marchioninistr. 15, 81377 Munich, Germany.
Radiologie Augsburg Friedberg ÜBAG, Hermanstraße 15, 86150 Augsburg, Germany.
Diagnostics (Basel). 2024 Dec 20;14(24):2866. doi: 10.3390/diagnostics14242866.
In suspected acute ischemic stroke, it is now reasonable to expand the conventional "stroke protocol" (non-contrast computed tomography (NCCT), arterial CT angiography (CTA), and optionally CT perfusion (CTP)) to early and late venous head scans yielding a multiphase CTA (MP-CTA) to increase diagnostic confidence. Diagnostic reference levels (DRLs) have been defined for neither MP-CTA nor CTP. We therefore present dosimetry data, while also considering image quality, for a large, unselected patient cohort.
A retrospective single-center study of 1790 patients undergoing the extended stroke protocol with three scanners (2× dual-source, DSCT; 1× single-source, SSCT) between 07/21 and 12/23 was conducted. For each sequence, we analyzed the radiation dose (volumetric CT dose index (CTDIvol); dose length product; effective dose); objective image quality using manually placed regions of interest (contrast-to-noise ratio (CNR)); and subjective image quality (4-point scale: 1 = non-diagnostic, 4 = excellent). The DRL was defined as the 75% percentile of the CTDIvol distribution. The Kruskal-Wallis test was used initially to test for overall equality of median values in each data group. Single post-test comparisons were performed with Dunn's test, with an overall statistical significance level of 0.05.
Dosimetry values were significantly higher for SSCT ( < 0.001, each). Local DRLs ranged between 37.3 and 49.1 mGy for NCCT, 3.6-5.5 mGy for arterial CTA, 1.2-2.5 mGy each for early/late venous CTA, and 141.1-220.5 mGy for CTP. Protocol adjustment (DSCT-1: CTP) yielded a 28.2% dose reduction. The highest/lowest CNRs (arterial/early venous CTA, respectively) were recorded for SSCT/DSCT-2 ( < 0.001). Subjective image quality was rated excellent except for slightly increased MP-CTA noise at DSCT-2 (median = 3).
Our data imply that additive MP-CTA scans only yield a minor increase in radiation exposure, particularly when using DSCT. CTP should be limited to selected patients.
在疑似急性缺血性卒中患者中，现在将传统的“卒中方案”（非增强计算机断层扫描（NCCT）、动脉CT血管造影（CTA）以及选择性CT灌注（CTP））扩展至早期和晚期头部静脉扫描以生成多期CTA（MP-CTA）从而提高诊断可信度是合理的。目前尚未为MP-CTA和CTP定义诊断参考水平（DRL）。因此，我们给出了针对一个未经过筛选的大型患者队列的剂量测定数据，同时也考虑了图像质量。
对2021年7月至2023年12月期间使用三台扫描仪（2台双源DSCT；1台单源SSCT）接受扩展卒中方案检查的1790例患者进行了一项回顾性单中心研究。对于每个序列，我们分析了辐射剂量（容积CT剂量指数（CTDIvol）、剂量长度乘积、有效剂量）；使用手动放置的感兴趣区域的客观图像质量（对比噪声比（CNR））；以及主观图像质量（4分制：1 = 非诊断性，4 = 优秀）。DRL定义为CTDIvol分布的第75百分位数。最初使用Kruskal-Wallis检验来检验每个数据组中位数的总体相等性。使用Dunn检验进行单后测比较，总体统计显著性水平为0.05。
SSCT的剂量测定值显著更高（每项均P < 0.001）。NCCT的局部DRL范围为37.3至49.1 mGy，动脉CTA为3.6至5.5 mGy，早期/晚期静脉CTA各为1.2至2.5 mGy，CTP为141.1至220.5 mGy。方案调整（DSCT-1：CTP）使剂量降低了28.2%。SSCT/DSCT-2分别记录到最高/最低的CNR（分别为动脉/早期静脉CTA）（P < 0.001）。除了DSCT-2的MP-CTA噪声略有增加（中位数 = 3）外，主观图像质量被评为优秀。
我们的数据表明，额外的MP-CTA扫描只会使辐射暴露略有增加，尤其是在使用DSCT时。CTP应仅限于选定的患者。
