Lee Chang Kyung, Seo Nieun, Kim Bohyun, Huh Jimi, Kim Jeong Kon, Lee Seung Soo, Kim In Seong, Nickel Dominik, Kim Kyung Won
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.
Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea.; Department of Radiology, Yonsei University College of Medicine, Severance Hospital, Seoul 03722, Korea.
Korean J Radiol. 2017 Mar-Apr;18(2):289-298. doi: 10.3348/kjr.2017.18.2.289. Epub 2017 Feb 7.
To compare the breathing effects on dynamic contrast-enhanced (DCE)-MRI between controlled aliasing in parallel imaging results in higher acceleration (CAIPIRINHA)-volumetric interpolated breath-hold examination (VIBE), radial VIBE with k-space-weighted image contrast view-sharing (radial-VIBE), and conventional VIBE (c-VIBE) sequences using a dedicated phantom experiment.
We developed a moving platform to simulate breathing motion. We conducted dynamic scanning on a 3T machine (MAGNETOM Skyra, Siemens Healthcare) using CAIPIRINHA-VIBE, radial-VIBE, and c-VIBE for six minutes per sequence. We acquired MRI images of the phantom in both static and moving modes, and we also obtained motion-corrected images for the motion mode. We compared the signal stability and signal-to-noise ratio (SNR) of each sequence according to motion state and used the coefficients of variation (CoV) to determine the degree of signal stability.
With motion, CAIPIRINHA-VIBE showed the best image quality, and the motion correction aligned the images very well. The CoV (%) of CAIPIRINHA-VIBE in the moving mode (18.65) decreased significantly after the motion correction (2.56) ( < 0.001). In contrast, c-VIBE showed severe breathing motion artifacts that did not improve after motion correction. For radial-VIBE, the position of the phantom in the images did not change during motion, but streak artifacts significantly degraded image quality, also after motion correction. In addition, SNR increased in both CAIPIRINHA-VIBE (from 3.37 to 9.41, < 0.001) and radial-VIBE (from 4.3 to 4.96, < 0.001) after motion correction.
CAIPIRINHA-VIBE performed best for free-breathing DCE-MRI after motion correction, with excellent image quality.
通过专用体模实验，比较并行成像中控制混叠以实现更高加速度（CAIPIRINHA）-容积内插屏气检查（VIBE）序列、具有k空间加权图像对比度视图共享的径向VIBE（radial-VIBE）序列和传统VIBE（c-VIBE）序列在动态对比增强（DCE）-MRI中的呼吸效应。
我们开发了一个移动平台来模拟呼吸运动。我们在一台3T机器（MAGNETOM Skyra，西门子医疗）上进行动态扫描，每个序列使用CAIPIRINHA-VIBE、radial-VIBE和c-VIBE扫描6分钟。我们在静态和运动模式下采集了体模的MRI图像，并且还获得了运动模式下的运动校正图像。我们根据运动状态比较了每个序列的信号稳定性和信噪比（SNR），并使用变异系数（CoV）来确定信号稳定性程度。
在运动状态下，CAIPIRINHA-VIBE显示出最佳图像质量，并且运动校正使图像对齐得非常好。运动校正后，CAIPIRINHA-VIBE在运动模式下的CoV（%）（18.65）显著降低（2.56）（<0.001）。相比之下，c-VIBE显示出严重的呼吸运动伪影，运动校正后并未改善。对于radial-VIBE，体模在图像中的位置在运动过程中没有变化，但条纹伪影显著降低了图像质量，运动校正后也是如此。此外，运动校正后，CAIPIRINHA-VIBE（从3.37提高到9.41, <0.001）和radial-VIBE（从4.3提高到4.96, <0.001）的SNR均有所增加。
运动校正后，CAIPIRINHA-VIBE在自由呼吸DCE-MRI中表现最佳，具有出色的图像质量。
