Bustin Aurélien, Rashid Imran, Cruz Gastao, Hajhosseiny Reza, Correia Teresa, Neji Radhouene, Rajani Ronak, Ismail Tevfik F, Botnar René M, Prieto Claudia
Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, St Thomas' Hospital, 3rd Floor, Lambeth Wing, London, SE1 7EH, UK.
National Heart and Lung Institute, Imperial College London, London, UK.
J Cardiovasc Magn Reson. 2020 Apr 16;22(1):24. doi: 10.1186/s12968-020-00611-5.
To enable free-breathing whole-heart sub-millimeter resolution coronary magnetic resonance angiography (CMRA) in a clinically feasible scan time by combining low-rank patch-based undersampled reconstruction (3D-PROST) with a highly accelerated non-rigid motion correction framework.
Non-rigid motion corrected CMRA combined with 2D image-based navigators has been previously proposed to enable 100% respiratory scan efficiency in modestly undersampled acquisitions. Achieving sub-millimeter isotropic resolution with such techniques still requires prohibitively long acquisition times. We propose to combine 3D-PROST reconstruction with a highly accelerated non-rigid motion correction framework to achieve sub-millimeter resolution CMRA in less than 10 min. Ten healthy subjects and eight patients with suspected coronary artery disease underwent 4-5-fold accelerated free-breathing whole-heart CMRA with 0.9 mm isotropic resolution. Vessel sharpness, vessel length and image quality obtained with the proposed non-rigid (NR) PROST approach were compared against translational correction only (TC-PROST) and a previously proposed NR motion-compensated technique (non-rigid SENSE) in healthy subjects. For the patient study, image quality scoring and visual comparison with coronary computed tomography angiography (CCTA) were performed.
Average scan times [min:s] were 6:01 ± 0:59 (healthy subjects) and 8:29 ± 1:41 (patients). In healthy subjects, vessel sharpness of the left anterior descending (LAD) and right (RCA) coronary arteries were improved with the proposed non-rigid PROST (LAD: 51.2 ± 8.8%, RCA: 61.2 ± 9.1%) in comparison to TC-PROST (LAD: 43.8 ± 5.1%, P = 0.051, RCA: 54.3 ± 8.3%, P = 0.218) and non-rigid SENSE (LAD: 46.1 ± 5.8%, P = 0.223, RCA: 56.7 ± 9.6%, P = 0.50), although differences were not statistically significant. The average visual image quality score was significantly higher for NR-PROST (LAD: 3.2 ± 0.6, RCA: 3.3 ± 0.7) compared with TC-PROST (LAD: 2.1 ± 0.6, P = 0.018, RCA: 2.0 ± 0.7, P = 0.014) and non-rigid SENSE (LAD: 2.3 ± 0.5, P = 0.008, RCA: 2.5 ± 0.7, P = 0.016). In patients, the proposed approach showed good delineation of the coronaries, in agreement with CCTA, with image quality scores and vessel sharpness similar to that of healthy subjects.
We demonstrate the feasibility of combining high undersampling factors with non-rigid motion-compensated reconstruction to obtain high-quality sub-millimeter isotropic CMRA images in ~ 8 min. Validation in a larger cohort of patients with coronary artery disease is now warranted.
通过将基于低秩块的欠采样重建（3D-PROST）与高度加速的非刚性运动校正框架相结合，在临床可行的扫描时间内实现自由呼吸全心亚毫米分辨率冠状动脉磁共振血管造影（CMRA）。
先前已提出将非刚性运动校正的CMRA与基于二维图像的导航器相结合，以在适度欠采样采集中实现100%的呼吸扫描效率。使用此类技术实现亚毫米各向同性分辨率仍需要极长的采集时间。我们建议将3D-PROST重建与高度加速的非刚性运动校正框架相结合，以在不到10分钟的时间内实现亚毫米分辨率的CMRA。10名健康受试者和8名疑似冠心病患者接受了4-5倍加速的自由呼吸全心CMRA，各向同性分辨率为0.9毫米。将所提出的非刚性（NR）PROST方法获得的血管清晰度、血管长度和图像质量与仅进行平移校正（TC-PROST）以及先前提出的NR运动补偿技术（非刚性SENSE）在健康受试者中的情况进行比较。对于患者研究，进行了图像质量评分并与冠状动脉计算机断层扫描血管造影（CCTA）进行视觉比较。
平均扫描时间[分钟:秒]为6:01±0:59（健康受试者）和8:29±1:41（患者）。在健康受试者中，与TC-PROST（左前降支：43.8±5.1%，P = 0.051，右冠状动脉：54.3±8.3%，P = 0.218）和非刚性SENSE（左前降支：46.1±5.8%，P = 0.223，右冠状动脉：56.7±9.6%，P = 0.50）相比，所提出的非刚性PROST使左前降支（LAD）和右冠状动脉（RCA）的血管清晰度有所提高（LAD：51.2±8.8%，RCA：61.2±9.1%），尽管差异无统计学意义。与TC-PROST（LAD：2.1±0.6，P = 0.018，RCA：2.0±0.7，P = 0.014）和非刚性SENSE（LAD：2.3±0.5，P = 0.008，RCA：2.5±0.7，P = 0.016）相比，NR-PROST的平均视觉图像质量评分显著更高（LAD：3.2±0.6；RCA：3.3±0.7）。在患者中，所提出的方法显示出冠状动脉的良好描绘，与CCTA一致，图像质量评分和血管清晰度与健康受试者相似。
我们证明了将高欠采样因子与非刚性运动补偿重建相结合以在约8分钟内获得高质量亚毫米各向同性CMRA图像的可行性。现在有必要在更大的冠心病患者队列中进行验证。
