Department of Cardiology, Boston Children's Hospital, Boston, MA, USA; Department of Pediatrics, Harvard Medical School, Boston, MA, USA.
Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands.
Magn Reson Imaging. 2020 Dec;74:203-212. doi: 10.1016/j.mri.2020.09.026. Epub 2020 Oct 7.
Current cardiovascular magnetic resonance (CMR) examinations require expert planning, multiple breath holds, and 2D imaging. To address this, we sought to develop and validate a comprehensive free-breathing 3D cine function and flow CMR examination using a steady-state free precession (SSFP) sequence to depict anatomy fused with a spatially registered phase contrast (PC) sequence for blood flow analysis.
In a prospective study, 25 patients underwent a CMR examination which included a 3D cine SSFP sequence and a 3D cine PC (also known as 4D flow) sequence acquired during free-breathing and after the administration of a gadolinium-based contrast agent. Both 3D sequences covered the heart and mediastinum, and used retrospective vectorcardiogram gating (20 phases/beat interpolated to 30 phases/beat) and prospective respiratory motion compensation confining data acquisition to end-expiration. Cardiovascular measurements derived from the 3D cine SSFP and PC images were then compared with those from standard 2D imaging.
All 3D cine SSFP and PC acquisitions were completed successfully. The mean time for the 3D cine sequences including prescription was shorter than that for the corresponding 2D sequences (21 min vs. 36 min, P-value <0.001). Left and right ventricular end-diastolic volumes and stroke volumes by 3D cine SSFP were slightly smaller than those from 2D cine SSFP (all biases ≤5%). The blood flow measurements from the 3D and 2D sequences had close agreement in the ascending aorta (bias -2.6%) but main pulmonary artery flow was lower with the 3D cine sequence (bias -11.2%).
Compared to the conventional 2D cine approach, a comprehensive 3D cine function and flow examination was faster and yielded slightly lower left and right end-diastolic volumes, stroke volumes, and main pulmonary artery blood flow. This free-breathing 3D cine approach allows flexible post-examination data analysis and has the potential to make examinations more comfortable for patients and easier to perform for the operator.
目前的心血管磁共振（CMR）检查需要专家进行规划、多次屏气和二维成像。为了解决这个问题，我们试图开发和验证一种全面的自由呼吸三维电影功能和流动 CMR 检查，使用稳态自由进动（SSFP）序列来描绘解剖结构，同时使用空间配准的相位对比（PC）序列进行血流分析。
在一项前瞻性研究中，25 名患者接受了 CMR 检查，包括 3D 电影 SSFP 序列和 3D 电影 PC（也称为 4D 流动）序列，这些序列是在自由呼吸和注射钆基造影剂后采集的。这两个 3D 序列都覆盖了心脏和纵隔，使用回顾性向量心电图门控（20 个相位/心跳插值至 30 个相位/心跳）和前瞻性呼吸运动补偿将数据采集限制在呼气末期。然后将从 3D 电影 SSFP 和 PC 图像中得出的心血管测量值与标准 2D 成像进行比较。
所有 3D 电影 SSFP 和 PC 采集都成功完成。包括处方在内的 3D 电影序列的平均时间比相应的 2D 序列短（21 分钟对 36 分钟，P 值<0.001）。左、右心室舒张末期容积和 3D 电影 SSFP 的每搏量略小于 2D 电影 SSFP（所有偏差≤5%）。升主动脉的 3D 和 2D 序列的血流测量值有很好的一致性（偏差-2.6%），但主肺动脉的血流较低（偏差-11.2%）。
与传统的 2D 电影方法相比，全面的 3D 电影功能和流动检查更快，左、右心室舒张末期容积、每搏量和主肺动脉血流略低。这种自由呼吸的 3D 电影方法允许灵活的检查后数据分析，并有潜力使检查对患者更舒适，对操作者更容易进行。
