Department of Radiology, Stanford University, Stanford, California, USA.
Department of Electrical Engineering, Stanford University, Stanford, California, USA.
Magn Reson Med. 2018 Aug;80(2):529-537. doi: 10.1002/mrm.27045. Epub 2017 Dec 17.
To demonstrate and evaluate the scan time and quantitative accuracy of simultaneous bilateral-knee imaging compared with single-knee acquisitions.
Hardware modifications and safety testing was performed to enable MR imaging with two 16-channel flexible coil arrays. Noise covariance and sensitivity-encoding g-factor maps for the dual-coil-array configuration were computed to evaluate coil cross-talk and noise amplification. Ten healthy volunteers were imaged on a 3T MRI scanner with both dual-coil-array bilateral-knee and single-coil-array single-knee configurations. Two experienced musculoskeletal radiologists compared the relative image quality between blinded image pairs acquired with each configuration. Differences in T relaxation time measurements between dual-coil-array and single-coil-array acquisitions were compared with the standard repeatability of single-coil-array measurements using a Bland-Altman analysis.
The mean g-factors for the dual-coil-array configuration were low for accelerations up to 6 in the right-left direction, and minimal cross-talk was observed between the two coil arrays. Image quality ratings of various joint tissues showed no difference in 89% (95% confidence interval: 85-93%) of rated image pairs, with only small differences ("slightly better" or "slightly worse") in image quality observed. The T relaxation time measurements between the dual-coil-array configuration and the single-coil configuration showed similar limits of agreement and concordance correlation coefficients (limits of agreement: -0.93 to 1.99 ms; CCC: 0.97 (95% confidence interval: 0.96-0.98)), to the repeatability of single-coil-array measurements (limits of agreement: -2.07 to 1.96 ms; CCC: 0.97 (95% confidence interval: 0.95-0.98)).
A bilateral coil-array setup can image both knees simultaneously in similar scan times as conventional unilateral knee scans, with comparable image quality and quantitative accuracy. This has the potential to improve the value of MRI knee evaluations. Magn Reson Med 80:529-537, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
展示和评估双侧膝关节磁共振成像（MRI）与单侧膝关节 MRI 相比的扫描时间和定量准确性。
进行硬件修改和安全测试，以实现使用两个 16 通道柔性线圈阵列的 MRI。计算双线圈阵列配置的噪声协方差和灵敏度编码 g 因子图，以评估线圈串扰和噪声放大。10 名健康志愿者在 3T MRI 扫描仪上分别进行双侧双线圈阵列膝关节和单侧单线圈阵列膝关节成像。两位有经验的肌肉骨骼放射科医生比较了使用每种配置采集的盲法图像对之间的相对图像质量。使用 Bland-Altman 分析比较双侧双线圈阵列和单侧单线圈阵列采集之间 T 弛豫时间测量值的差异与单线圈阵列测量值的标准重复性。
双线圈阵列配置的平均 g 因子在右-左方向上的加速达到 6 时较低，并且两个线圈阵列之间观察到最小的串扰。各种关节组织的图像质量评分显示，在 89%（95%置信区间：85-93%）的评分图像对中没有差异，只有很小的差异（“稍好”或“稍差”）观察到图像质量。双线圈阵列配置和单线圈配置之间的 T 弛豫时间测量值具有相似的一致性界限和相关性系数（一致性界限：-0.93 至 1.99 ms；CCC：0.97（95%置信区间：0.96-0.98）），与单线圈阵列测量值的重复性相当（一致性界限：-2.07 至 1.96 ms；CCC：0.97（95%置信区间：0.95-0.98））。
双侧线圈阵列设置可以在与传统单侧膝关节扫描相似的扫描时间内同时对两个膝关节进行成像，具有可比的图像质量和定量准确性。这有可能提高 MRI 膝关节评估的价值。磁共振医学 80:529-537, 2018. © 2017 国际磁共振学会。
