Abdulazim Amr, Rubbert Christian, Reichelt Dorothea, Mathys Christian, Turowski Bernd, Steiger Hans-Jakob, Hänggi Daniel, Etminan Nima
Department of Neurosurgery, University Hospital Mannheim, University of Heidelberg, Mannheim, Germany.
Cerebrovasc Dis. 2017;43(5-6):272-282. doi: 10.1159/000464356. Epub 2017 Mar 21.
The invasiveness and risk of thromboembolic complications of catheter angiography underline the need for alternative imaging modalities in patients following intracranial aneurysm (IA) repair. However, the overall image quality of existing noninvasive imaging modalities, such as single-energy CT angiography (SE-CTA), compromises its value in this respect.
We prospectively investigated the value of a novel dual-energy CTA (DE-CTA) scanner and algorithm for assessing the degree of occlusion and parent vessel patency in patients following IA repair.
A prospective cohort of 17 patients underwent DE-CTA imaging following surgical or endovascular IA repair. This dataset was matched with an identical historical cohort of 17 patients, who underwent IA repair and SE-CTA imaging. Beam-hardening artifacts, as a measure for objective imaging quality were analyzed based on the volume of a prolate ellipsoid, whereas subjective imaging quality at the IA site and corresponding parent vessels was rated by 2 independent neuroradiologists on a scale from 4 (excellent, no artifacts) to 1 (poor, severe artifacts).
Objective DE-CTA image quality was markedly higher, compared to SE-CTA in patients undergoing surgical (0.77 ± 0.23 vs. 10.91 ± 1.88 mL, respectively; p < 0.001) or endovascular (32.36 ± 10.62 vs. 107.63 ± 24.51 mL, respectively; p = 0.026) IA repair. Subjective image quality for DE-CTA was significantly improved compared to SE-CTA in the surgical group but not in the endovascular group. The calculated dose values for DE-CTA in our study remain markedly below the legally required radiation dose limits.
The imaging quality of DE-CTA, especially for patients undergoing surgical IA repair, is distinctly superior, compared to SE-CTA imaging. Therefore, DE-CTA may serve as a noninvasive alternative for assessing the IA occlusion rate and parent vessel patency.
导管血管造影的侵袭性和血栓栓塞并发症风险凸显了颅内动脉瘤（IA）修复术后患者需要替代成像方式的必要性。然而，现有的非侵入性成像方式，如单能量CT血管造影（SE-CTA），其整体图像质量在这方面降低了其价值。
我们前瞻性地研究了一种新型双能量CT血管造影（DE-CTA）扫描仪和算法在评估IA修复术后患者闭塞程度和供血血管通畅性方面的价值。
17例患者在接受手术或血管内IA修复后接受了DE-CTA成像。该数据集与17例接受IA修复和SE-CTA成像的相同历史队列患者相匹配。基于一个长椭圆形的体积分析了束硬化伪影，作为客观成像质量的一种衡量指标，而由2名独立的神经放射科医生对IA部位和相应供血血管的主观成像质量进行评分，评分范围为4分（优秀，无伪影）至1分（差，严重伪影）。
与接受手术（分别为0.77±0.23 vs. 10.91±1.88 mL；p<0.001）或血管内（分别为32.36±10.62 vs. 107.63±24.51 mL；p = 0.026）IA修复的患者中的SE-CTA相比，DE-CTA的客观图像质量明显更高。与SE-CTA相比，手术组中DE-CTA的主观图像质量显著提高，但血管内组未提高。我们研究中DE-CTA的计算剂量值仍明显低于法定要求的辐射剂量限值。
与SE-CTA成像相比，DE-CTA的成像质量，特别是对于接受手术IA修复的患者，明显更优。因此，DE-CTA可作为评估IA闭塞率和供血血管通畅性的非侵入性替代方法。
