Guo Yi, Lebel R Marc, Zhu Yinghua, Lingala Sajan Goud, Shiroishi Mark S, Law Meng, Nayak Krishna
Ming Hsieh Department of Electrical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California 90089.
GE Healthcare, Calgary, Alberta AB T2P 1G1, Canada.
Med Phys. 2016 May;43(5):2013. doi: 10.1118/1.4944736.
To clinically evaluate a highly accelerated T1-weighted dynamic contrast-enhanced (DCE) MRI technique that provides high spatial resolution and whole-brain coverage via undersampling and constrained reconstruction with multiple sparsity constraints.
Conventional (rate-2 SENSE) and experimental DCE-MRI (rate-30) scans were performed 20 minutes apart in 15 brain tumor patients. The conventional clinical DCE-MRI had voxel dimensions 0.9 × 1.3 × 7.0 mm(3), FOV 22 × 22 × 4.2 cm(3), and the experimental DCE-MRI had voxel dimensions 0.9 × 0.9 × 1.9 mm(3), and broader coverage 22 × 22 × 19 cm(3). Temporal resolution was 5 s for both protocols. Time-resolved images and blood-brain barrier permeability maps were qualitatively evaluated by two radiologists.
The experimental DCE-MRI scans showed no loss of qualitative information in any of the cases, while achieving substantially higher spatial resolution and whole-brain spatial coverage. Average qualitative scores (from 0 to 3) were 2.1 for the experimental scans and 1.1 for the conventional clinical scans.
The proposed DCE-MRI approach provides clinically superior image quality with higher spatial resolution and coverage than currently available approaches. These advantages may allow comprehensive permeability mapping in the brain, which is especially valuable in the setting of large lesions or multiple lesions spread throughout the brain.
临床评估一种高度加速的T1加权动态对比增强(DCE)MRI技术,该技术通过欠采样和具有多个稀疏约束的约束重建来提供高空间分辨率和全脑覆盖。
对15例脑肿瘤患者进行常规(加速因子为2的敏感度编码[SENSE])和实验性DCE-MRI(加速因子为30)扫描,两次扫描间隔20分钟。常规临床DCE-MRI的体素尺寸为0.9×1.3×7.0 mm³,视野(FOV)为22×22×4.2 cm³,实验性DCE-MRI的体素尺寸为0.9×0.9×1.9 mm³,覆盖范围更广,为22×22×19 cm³。两种扫描方案的时间分辨率均为5秒。两名放射科医生对时间分辨图像和血脑屏障通透性图进行了定性评估。
实验性DCE-MRI扫描在所有病例中均未显示定性信息丢失,同时实现了显著更高的空间分辨率和全脑空间覆盖。实验性扫描的平均定性评分(0至3分)为2.1分,常规临床扫描为1.1分。
所提出的DCE-MRI方法提供了临床上更优的图像质量,具有比现有方法更高的空间分辨率和覆盖范围。这些优势可能使大脑的通透性全面映射成为可能,这在大病变或遍布全脑的多个病变的情况下尤其有价值。