Department of Radiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju, South Korea.
Department of Radiology, Gyeongsang National University Changwon Hospital, 555 Samjeongja-dong, Seongsan-gu, Changwon, South Korea.
Eur Radiol. 2020 Sep;30(9):5130-5138. doi: 10.1007/s00330-020-06890-x. Epub 2020 Apr 24.
To evaluate the feasibility and image quality of respiratory motion-resolved 4D zero echo time (ZTE) lung MRI compared with that of 3D ZTE.
Our institutional review board approved this study. Twenty-one patients underwent lung scans using 3D ZTE and 4D ZTE sequences via prospective and retrospective soft gating techniques, respectively. Image qualities of 3D ZTE and 4D ZTE at end-expiration were compared through objective and subjective assessments. The quality of end-expiratory images of 3D ZTE and 4D ZTE of the two groups with different lung functions was also compared.
Images were successfully acquired in all patients without any adverse events. Signal-to-noise ratios (SNRs) of lung parenchyma and thoracic structures were significantly (all p < 0.001) higher in 4D ZTE. Contrast-to-noise ratios (CNRs) of peripheral bronchi, peripheral pulmonary vessels, and nodules or masses were significantly (all p < 0.001) higher in 4D ZTE. The subjective image quality assessed by two independent radiologists showed that intrapulmonary structures, noise and artifacts, and overall acceptability were superior in 4D ZTE (all p < 0.001). Image qualities of groups with normal and low lung functions differed significantly (all p < 0.05) in 3D ZTE, but not in 4D ZTE. The mean acquisition time was 136 s (127-143 s) in 3D ZTE and 325 s (308-352 s) in 4D ZTE.
Respiratory motion-resolved 4D ZTE lung imaging was feasible as part of routine chest MRI. The 4D ZTE provides motion-robust lung parenchymal images with better SNR and CNR than the 3D ZTE, regardless of patients' lung function.
• ZTE MRI captures rapidly decaying transverse magnetization in the lung parenchyma. • 4D ZTE provides motion-robust lung parenchymal images with better SNR and CNR compared with 3D ZTE. • Compared with 3D ZTE, the image quality of 4D ZTE lung MRI was affected less by patients' lung function and respiratory performance.
评估呼吸运动分辨的 4D 零回波时间（ZTE）肺部 MRI 的可行性和图像质量，与 3D ZTE 相比。
本机构审查委员会批准了这项研究。21 例患者分别通过前瞻性和回顾性软门控技术进行 3D ZTE 和 4D ZTE 序列的肺部扫描。通过客观和主观评估比较 3D ZTE 和 4D ZTE 在呼气末的图像质量。还比较了两组不同肺功能的 3D ZTE 和 4D ZTE 的呼气末图像质量。
所有患者均成功采集图像，无不良事件发生。肺实质和胸部结构的信噪比（SNR）在 4D ZTE 中显著提高（均 p < 0.001）。周围支气管、周围肺血管、结节或肿块的对比噪声比（CNR）在 4D ZTE 中显著提高（均 p < 0.001）。两位独立放射科医生主观评估的图像质量显示，4D ZTE 中肺内结构、噪声和伪影以及整体可接受性更好（均 p < 0.001）。3D ZTE 中，正常和低肺功能组的图像质量差异显著（均 p < 0.05），但 4D ZTE 中则无差异。3D ZTE 的平均采集时间为 136 s（127-143 s），4D ZTE 为 325 s（308-352 s）。
呼吸运动分辨的 4D ZTE 肺部成像作为常规胸部 MRI 的一部分是可行的。4D ZTE 提供了运动稳健的肺实质图像，与 3D ZTE 相比，具有更好的 SNR 和 CNR，而与患者的肺功能无关。
ZTE MRI 捕获肺部实质中快速衰减的横向磁化。
与 3D ZTE 相比，4D ZTE 提供了运动稳健的肺实质图像，具有更好的 SNR 和 CNR。
与 3D ZTE 相比，4D ZTE 肺部 MRI 的图像质量受患者肺功能和呼吸表现的影响较小。
