From the Department of Radiology (M.J.H.), University of Pennsylvania, Philadelphia, Pennsylvania.
Department of Radiology (M.B., Y.W.L., E.F., T.M.S.), New York University Langone School of Medicine, New York, New York.
AJNR Am J Neuroradiol. 2021 Aug;42(8):1437-1443. doi: 10.3174/ajnr.A7140. Epub 2021 May 13.
Diffusion MR imaging sequences essential for clinical neuroradiology imaging protocols may be accelerated with simultaneous multislice acquisitions. We tested whether simultaneous multislice-accelerated diffusion data were clinically equivalent to standard acquisitions.
In this retrospective study, clinical diffusion sequences obtained before and after implementation of 2-slice simultaneous multislice acceleration and an altered diffusion gradient sampling scheme using the same 3T MRI scanner and 20-channel coil ( = 25 per group) were independently and blindly evaluated by 2 neuroradiologists for perceived quality, artifacts, and overall diagnostic utility. Diffusion tractography was performed in 13 patients both with and without 2-slice simultaneous multislice acceleration ( = 0, 1000, 2000 s/mm; 60 directions). The corticospinal tract and arcuate fasciculus ipsilateral to the lesion were generated using the same ROIs and then blindly assessed by a neurosurgeon for anatomic fidelity, perceived quality, and impact on surgical management. Tract volumes were compared for spatial overlap.
Two-slice simultaneous multislice diffusion reduced acquisition times from 141 to 45 seconds for routine diffusion and from 7.5 to 5.9 minutes for diffusion tractography using 3T MR imaging. The simultaneous multislice-accelerated diffusion sequence was rated equivalent for diagnostic utility despite reductions to perceived image quality. Simultaneous multislice-accelerated diffusion tractography was rated clinically equivalent. Dice similarity coefficients between routine and simultaneous multislice-generated corticospinal tract and arcuate fasciculus tract volumes were 0.78 (SD, 0.03) and 0.71 (SD, 0.05), respectively.
Two-slice simultaneous multislice diffusion appeared clinically equivalent for standard acquisitions and diffusion tractography. Simultaneous multislice makes it feasible to acquire higher angular and -space-resolution diffusion acquisitions required for translating advanced diffusion models into clinical practice.
扩散磁共振成像序列对于临床神经影像学成像方案至关重要，可通过同时多层采集来加速。我们测试了同时多层加速扩散数据是否与标准采集具有临床等效性。
在这项回顾性研究中，使用相同的 3T MRI 扫描仪和 20 通道线圈，在实施 2 层同时多层加速和改变扩散梯度采样方案前后，分别获得了 25 例临床扩散序列（每组 25 例），由 2 名神经放射科医生独立和盲目评估感知质量、伪影和整体诊断效用。在 13 例患者中均进行了 2 层同时多层加速（0、1000、2000 s/mm；60 个方向）和无 2 层同时多层加速的扩散轨迹成像。使用相同的 ROI 生成病变对侧皮质脊髓束和弓状束，然后由神经外科医生盲目评估解剖保真度、感知质量和对手术管理的影响。比较了轨迹体积的空间重叠。
2 层同时多层扩散将常规扩散的采集时间从 141 秒缩短至 45 秒，将扩散轨迹成像的采集时间从 7.5 分钟缩短至 5.9 分钟。尽管感知图像质量下降，但同时多层加速扩散序列的诊断效用仍被评为等效。同时多层加速扩散轨迹成像被评为临床等效。常规和同时多层生成的皮质脊髓束和弓状束轨迹体积的 Dice 相似系数分别为 0.78（标准差，0.03）和 0.71（标准差，0.05）。
2 层同时多层扩散对于标准采集和扩散轨迹成像似乎具有临床等效性。同时多层加速使得获取高级扩散模型转化为临床实践所需的更高角度和 -空间分辨率的扩散采集成为可能。
