Palosaari Kari, Tervonen Osmo
Department of Diagnostic Radiology, University Hospital of Oulu, Kajaanintie 50, FIN-90229 Oulu, Finland.
MAGMA. 2002 Nov;15(1-3):1-9. doi: 10.1007/BF02693838.
To evaluate the feasibility of the phase difference-based post-processing water-fat imaging method for fat suppression at low-field in imaging of arthritic joints.
Thirty joints (wrist, 10; elbow, 10; knee, 10) in 30 patients with rheumatoid arthritis were imaged using a 0.23T MRI unit. Contrast-enhanced T1-weighted (T1w) three-dimensional (3D) gradient-echo (GRE) images with and without fat suppression along with short inversion time inversion-recovery (STIR) images were evaluated by two radiologists. Contrast-enhanced T1w 3D GRE images and corresponding post-processed fat-suppressed images were scored for conspicuity and delineation of enhancing synovial hypertrophy. The uniformity of fat suppression was evaluated between T1w 3D GRE fat-suppressed images and STIR images, and general image quality was estimated for all of the three techniques by consensus. For a quantitative analysis, the enhancing synovial hypertrophy-to-fat contrast-to-noise (CNR) values for the T1W 3D GRE images with and without fat suppression were measured. For comparison, synovial bright signal-to-fat CNR values for the STIR images were measured.
The post-processing water-fat imaging technique for fat suppression was successfully applied in all examinations. Conspicuity and delineation of enhancing tissue were superior in fat-suppressed T1w 3D GRE images compared to non-fat-suppressed images (P < 0.0001). As expected, the enhancing synovial hypertrophy tissue-to-fat CNRs were significantly higher in fat-suppressed T1w 3D GRE images compared to non-fat-suppressed images (P < 0.0001). General image quality was assessed to be best in non-fat-suppressed images, and the difference was significant compared to fat-suppressed images (P < 0.05) and STIR images (P < 0.05).
The phase difference-based post-processing water-fat imaging technique for fat suppression can be successfully used at low-field, and it provides high-quality fat suppression images in imaging of arthritic joints.
评估基于相位差的后处理水脂成像方法在低场强下对关节炎关节成像进行脂肪抑制的可行性。
使用0.23T磁共振成像（MRI）设备对30例类风湿性关节炎患者的30个关节（腕关节10个、肘关节10个、膝关节10个）进行成像。由两名放射科医生对有脂肪抑制和无脂肪抑制的对比增强T1加权（T1w）三维（3D）梯度回波（GRE）图像以及短反转时间反转恢复（STIR）图像进行评估。对对比增强T1w 3D GRE图像和相应的后处理脂肪抑制图像进行评分，以评估增强滑膜肥厚的清晰度和轮廓。在T1w 3D GRE脂肪抑制图像和STIR图像之间评估脂肪抑制的均匀性，并通过共识对所有三种技术的总体图像质量进行评估。进行定量分析时，测量有脂肪抑制和无脂肪抑制的T1W 3D GRE图像中增强滑膜肥厚与脂肪的对比噪声比（CNR）值。作为比较，测量STIR图像中滑膜亮信号与脂肪的CNR值。
脂肪抑制的后处理水脂成像技术在所有检查中均成功应用。与未进行脂肪抑制的图像相比，脂肪抑制的T1w 3D GRE图像中增强组织的清晰度和轮廓更优（P < 0.0001）。正如预期的那样，与未进行脂肪抑制的图像相比，脂肪抑制的T1w 3D GRE图像中增强滑膜肥厚组织与脂肪的CNR显著更高（P < 0.0001）。总体图像质量评估显示未进行脂肪抑制的图像最佳，与脂肪抑制图像（P < 0.05）和STIR图像（P < 0.05）相比差异显著。
基于相位差的后处理水脂成像脂肪抑制技术可在低场强下成功应用，并且在关节炎关节成像中能提供高质量的脂肪抑制图像。
