Department of Clinical Radiology, Tottori University Hospital, Tottori, Japan.
Division of Neurosurgery, Department of Brain and Neurosciences, School of Medicine, Faculty of Medicine, Tottori University, Tottori, Japan.
Radiol Med. 2023 Oct;128(10):1262-1270. doi: 10.1007/s11547-023-01692-9. Epub 2023 Sep 1.
Follow-up examinations after flow diverter (FD) treatment for cerebral aneurysms typically involve magnetic resonance imaging (MRI) or digital subtraction angiography (DSA). However, MRI is prone to vascular defects due to metal artifacts from FD, and DSA carries a risk of ischemic complications. In the context of computed tomography angiography (CTA), this study compares the efficacy of ultra-high-resolution CT (UHRCT) and novel reconstruction techniques, such as model-based iterative reconstruction (MBIR), against conventional methods such as filtered back projection (FBP) and hybrid iterative reconstruction (IR), to determine if they are a viable alternative to DSA in clinical settings.
A phantom study was conducted with the full-width half-maximum considered as the FD thickness. This study compared three reconstruction methods: MBIR, FBP, and hybrid IR. A clinical study was also conducted with 21 patients who underwent follow-up CTA after FD treatment. The FD's visibility was assessed using a 4-point scale in FBP, hybrid IR, and MBIR compared to cone-beam CT (CBCT) with angiographic systems.
In the phantom study, FBP, hybrid IR, and MBIR visualized thinner FD thicknesses and improved detail rendering in that order. MBIR proved to be significantly superior in both the phantom and clinical study.
UHRCT with MBIR is highly effective for follow-up evaluations after FD treatment and may become the first-choice modality in the future.
脑动脉瘤血流导向装置（FD）治疗后的随访检查通常包括磁共振成像（MRI）或数字减影血管造影（DSA）。然而，由于 FD 的金属伪影，MRI 容易出现血管缺陷，而 DSA 则存在缺血性并发症的风险。在计算机断层血管造影（CTA）的背景下，本研究比较了超高分辨率 CT（UHRCT）和新型重建技术（如基于模型的迭代重建（MBIR））与传统方法（如滤波反投影（FBP）和混合迭代重建（IR））的效果，以确定它们是否可以替代 DSA 在临床环境中的应用。
使用全宽半最大值作为 FD 厚度进行了一项体模研究。该研究比较了三种重建方法：MBIR、FBP 和混合 IR。还对 21 例接受 FD 治疗后进行 CTA 随访的患者进行了临床研究。使用 4 分制评估 FD 在 FBP、混合 IR 和 MBIR 中的显示情况，并与血管造影系统的锥形束 CT（CBCT）进行比较。
在体模研究中，FBP、混合 IR 和 MBIR 依次显示更薄的 FD 厚度和改善的细节呈现。MBIR 在体模和临床研究中均表现出显著优势。
MBIR 的 UHRCT 对 FD 治疗后的随访评估非常有效，可能成为未来的首选方法。
