Runderkamp Bobby A, Caan Matthan W A, van der Zwaag Wietske, Hemke Robert, Maas Mario, Andersen Mads, Strijkers Gustav J, Markenroth Bloch Karin, Nederveen Aart J
Department of Radiology and Nuclear Medicine, Amsterdam University Medical Center, University of Amsterdam, Amsterdam Movement Sciences, Amsterdam, the Netherlands.
Department of Biomedical Engineering and Physics, Amsterdam University Medical Center, University of Amsterdam, Amsterdam Movement Sciences, Amsterdam, the Netherlands.
NMR Biomed. 2025 Jun;38(6):e70041. doi: 10.1002/nbm.70041.
This study aimed to obtain high-resolution 3D isotropic turbo spin-echo (TSE) wrist MRI acquisitions at 7T, with and without fat suppression, facilitated by compressed-sensing (CS) acceleration. In 16 healthy subjects, fat-suppressed (FS) and nonfat-suppressed (NFS) TSE wrist images were obtained. The protocol consisted of a SENSE-accelerated scan, with an isotropic voxel size of 0.45 mm and acquisition time of 7 min ("SENSE45"), a 0.45-mm, 4-min CS-accelerated scan ("CS45"), and a 0.35-mm, 7-min CS-accelerated scan ("CS35"). For two subjects, additional 0.45-mm, 4-min SENSE-accelerated scans were acquired ("High-SENSE"). For the NFS scans, refocusing pulses were optimized to mitigate water-fat chemical-shift artifacts in the slab-selection direction. Anatomical visibility of wrist structures and image quality were assessed qualitatively and through musculoskeletal radiologist grading. The use of nonselective hard refocusing pulses with optimized bandwidths and a center frequency in between water and fat enabled NFS imaging. The image quality of the faster CS45 scans was lower than for SENSE45, with statistically significantly different grading in 9/16 (FS) and 2/6 (NFS) grading parameters. Nonetheless, a similar scan time reduction could not be achieved using High-SENSE. No distinct benefit of CS35 compared to SENSE45 was evident in either the FS or NFS scans. NFS CS35 exhibited enhanced bone sharpness compared to SENSE45 for some subjects, yet on a group level, the difference was not statistically significant. In conclusion, for maintained voxel size, CS presents the opportunity to achieve shorter scan times than possible with SENSE alone, but with reduced image quality. For maintained scan time, although higher resolution CS incidentally showed a promising increase in NFS bone sharpness compared to SENSE, it does not present an unequivocal advantage for 3D 7-T TSE wrist MRI at this stage. Further optimization of the acquisition and reconstruction process is recommended.
本研究旨在通过压缩感知（CS）加速技术，在7T条件下获得高分辨率的三维各向同性涡轮自旋回波（TSE）手腕部磁共振成像（MRI），包括有脂肪抑制和无脂肪抑制的情况。对16名健康受试者获取了脂肪抑制（FS）和非脂肪抑制（NFS）的TSE手腕部图像。扫描方案包括一次敏感度编码（SENSE）加速扫描，各向同性体素大小为0.45毫米，采集时间为7分钟（“SENSE45”），一次0.45毫米、4分钟的CS加速扫描（“CS45”），以及一次0.35毫米、7分钟的CS加速扫描（“CS35”）。对两名受试者额外采集了0.45毫米、4分钟的SENSE加速扫描（“高SENSE”）。对于NFS扫描，优化了重聚焦脉冲以减轻层面选择方向上的水脂化学位移伪影。通过定性评估以及肌肉骨骼放射科医生分级，对手腕部结构的解剖学可视性和图像质量进行了评估。使用具有优化带宽且中心频率介于水和脂肪之间的非选择性硬重聚焦脉冲实现了NFS成像。更快的CS45扫描的图像质量低于SENSE45，在9/16（FS）和2/6（NFS）分级参数中具有统计学显著差异。尽管如此，使用高SENSE无法实现类似的扫描时间缩短。在FS或NFS扫描中，与SENSE45相比，CS35均未显示出明显优势。对于一些受试者，NFS CS35与SENSE45相比，骨锐利度有所增强，但在组水平上，差异无统计学意义。总之，对于保持体素大小，CS提供了比单独使用SENSE更短扫描时间的机会，但图像质量会降低。对于保持扫描时间，尽管更高分辨率的CS与SENSE相比，偶然显示出NFS骨锐利度有有望提高，但在现阶段，对于三维7-T TSE手腕部MRI，它并没有明确的优势。建议进一步优化采集和重建过程。
