Real-time cardiovascular magnetic resonance at 1.5 T using balanced SSFP and 40 ms resolution.
Real-time cardiovascular magnetic resonance at 1.5 T using balanced SSFP and 40 ms resolution.
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DOI：
10.1186/1532-429x-15-79
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发表时间：
2013-09-12
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影响因子：
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通讯作者：
Frahm J
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作者：
Voit D;Zhang S;Unterberg-Buchwald C;Sohns JM;Lotz J;Frahm J
虽然心血管磁共振 (CMR) 通常采用心电图同步电影采集，并在 1.5 T 下实现平衡稳态自由进动 (SSFP) 对比度，但 3 T 下的最新进展表明，使用欠采样径向 FLASH 在高时空分辨率下进行 T1 加权实时成像具有巨大潜力。这项工作的目的是将这两种想法结合起来，并在 1.5 T 和 SSFP 对比度下评估相应的实时 CMR 方法。在具有不同梯度性能的两个 CMR 系统上实现了具有完全平衡梯度和至少 15 倍欠采样的径向梯度回波序列。通过正则化非线性反演 (NLINV) 离线执行图像重建，生成标称分辨率为 1.8 毫米、采集时间为 40 毫秒的实时 SSFP CMR 图像。对健康受试者的研究证明了鲁棒性和一般图像质量方面的技术可行性。通过对 27 名具有 CMR 典型指征（包括心律失常和异常室壁运动）的患者的初步应用，证实了可进行定量评估（例如射血分数）的临床适用性。实时图像质量略低于电影 SSFP 记录，但在所有情况下都被认为具有诊断意义。扩展了传统的电影方法，具有 NLINV 重建功能的实时径向 SSFP CMR 提供了对个体心动周期的访问，并允许对心律不齐的患者进行研究。
While cardiovascular magnetic resonance (CMR) commonly employs ECG-synchronized cine acquisitions with balanced steady-state free precession (SSFP) contrast at 1.5 T, recent developments at 3 T demonstrate significant potential for T1-weighted real-time imaging at high spatiotemporal resolution using undersampled radial FLASH. The purpose of this work was to combine both ideas and to evaluate a corresponding real-time CMR method at 1.5 T with SSFP contrast. Radial gradient-echo sequences with fully balanced gradients and at least 15-fold undersampling were implemented on two CMR systems with different gradient performance. Image reconstruction by regularized nonlinear inversion (NLINV) was performed offline and resulted in real-time SSFP CMR images at a nominal resolution of 1.8 mm and with acquisition times of 40 ms. Studies of healthy subjects demonstrated technical feasibility in terms of robustness and general image quality. Clinical applicability with access to quantitative evaluations (e.g., ejection fraction) was confirmed by preliminary applications to 27 patients with typical indications for CMR including arrhythmias and abnormal wall motion. Real-time image quality was slightly lower than for cine SSFP recordings, but considered diagnostic in all cases. Extending conventional cine approaches, real-time radial SSFP CMR with NLINV reconstruction provides access to individual cardiac cycles and allows for studies of patients with irregular heartbeat.