Department of Diagnostic Imaging and Nuclear Medicine, Graduate School of Medicine, Kyoto University, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto, 606-8507, Japan.
Siemens Healthcare GmbH, Allee am Roethelheimpark 2, 91052, Erlangen, Germany.
Eur Radiol. 2022 Aug;32(8):5392-5401. doi: 10.1007/s00330-022-08678-7. Epub 2022 Mar 17.
To assess the feasibility of low-dose contrast-enhanced four-dimensional (4D) time-resolved angiography with stochastic trajectories (TWIST) with iterative reconstruction (hereafter IT-TWIST-MRA) covering the whole brain and to compare IT-TWIST-MRA and TWIST-MRA with reference to digital subtraction angiography (DSA) in the evaluation of arteriovenous shunts (AVS).
Institutional Review Board approval was obtained for this observational study, and the requirement for written informed consent was waived. Twenty-nine patients with known AVS underwent TWIST-MRA on a 3-T MRI scanner, using low-dose injection (0.02 mmol/kg) of gadolinium-based contrast agent (GBCA) with each of Fourier and iterative reconstruction between September 2016 and October 2019. Visual evaluation of image quality was conducted for delineation of (a) the normal cerebral arteries and veins and (b) AVS feeder, shunt, and drainer vessels. Region-of-interest evaluation was conducted to evaluate bolus sharpness and baseline signal fluctuation in the signal intensity of the cerebral vessels. We compared the detection of AVS between TWIST-MRA and IT-TWIST-MRA. The paired-samples Wilcoxon test was used to test the differences between TWIST-MRA and IT-TWIST-MRA.
Visualization scores for normal vasculature and AVS angioarchitecture were significantly better for images produced using IT-TWIST-MRA than those using TWIST-MRA. Peak signal and the enhancement slope of the time-intensity curve were significantly higher for IT-TWIST-MRA than for TWIST-MRA, except for the superior sagittal sinus (SSS). Baseline intensity fluctuation was significantly lower for IT-TWIST-MRA than for TWIST, except for SSS.
IT-TWIST-MRA yields clinically feasible 4D MR-DSA images and delineates AVS even with low-dose GBCA.
• Iterative reconstruction significantly improves the image quality of TWIST-MRA covering the whole brain. • The short temporal footprint and denoising effect of iterative reconstruction enhances the quality of 4D-MRA. • IT-TWIST-MRA yields clinically feasible images of AVS with low-dose GBCA.
评估低剂量对比增强四维（4D）时间分辨血管造影随机轨迹（TWIST）与迭代重建（以下简称 IT-TWIST-MRA）覆盖全脑的可行性，并将 IT-TWIST-MRA 与 TWIST-MRA 与数字减影血管造影（DSA）进行比较，评估动静脉分流（AVS）。
本观察性研究获得了机构审查委员会的批准，并豁免了书面知情同意的要求。29 例已知 AVS 的患者于 2016 年 9 月至 2019 年 10 月在 3T MRI 扫描仪上进行 TWIST-MRA 检查，采用低剂量（0.02mmol/kg）钆基对比剂（GBCA）进行傅立叶和迭代重建。对图像质量进行视觉评估，以描绘（a）正常脑动脉和静脉和（b）AVS 供血、分流和引流血管。对感兴趣区域进行评估，以评估脑血管信号强度的对比剂峰值锐利度和基线信号波动。我们比较了 TWIST-MRA 和 IT-TWIST-MRA 对 AVS 的检测。采用配对样本 Wilcoxon 检验比较 TWIST-MRA 和 IT-TWIST-MRA 之间的差异。
IT-TWIST-MRA 生成的图像对正常血管和 AVS 血管结构的可视化评分明显优于 TWIST-MRA 生成的图像。IT-TWIST-MRA 的峰值信号和时间-强度曲线的增强斜率明显高于 TWIST-MRA，除了上矢状窦（SSS）。除了 SSS 外，IT-TWIST-MRA 的基线强度波动明显低于 TWIST。
IT-TWIST-MRA 可产生具有临床可行性的 4D MR-DSA 图像，并可在低剂量 GBCA 下描绘 AVS。
• 迭代重建可显著提高覆盖全脑的 TWIST-MRA 的图像质量。• 迭代重建的短时间足迹和降噪效果可提高 4D-MRA 的质量。• IT-TWIST-MRA 可在低剂量 GBCA 下产生具有临床可行性的 AVS 图像。
