Department of Radiology, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.
MR Application Predevelopment, Siemens Healthcare GmbH, Erlangen, Germany.
J Magn Reson Imaging. 2021 Sep;54(3):715-720. doi: 10.1002/jmri.27590. Epub 2021 Mar 11.
Reduced field-of-view diffusion-weighted imaging (rDWI) with tilted two-dimensional radiofrequency (RF) excitation planes has not yet been applied to the imaging of the pancreas although the utility of this technique which allows the acquisition of high-quality images without aliasing artifacts in the phase-encoding direction has been evaluated for brain and spinal cord imaging.
To evaluate the visual image quality of the pancreas by tilting the excitation plane (tilted rDWI) in comparison to conventional DWI (cDWI) and rDWI without using the tilted excitation plane.
Retrospective.
Thirty-two patients evaluated for suspected pancreatobiliary diseases.
FIELD STRENGTH/SEQUENCE: Echo-planar imaging DWI (cDWI, rDWI, and tilted rDWI) acquired at 3 T.
Images from each DWI sequence were analyzed by five radiologists to compare image quality (conspicuity of pancreatic edges, interslice signal homogeneity, overall image quality, and conspicuity of focal pancreatic lesions) and artifacts (presence of blurring or ghosting artifacts, susceptibility artifacts, and aliasing artifact).
Shapiro-Wilk test was performed to assess whether data were normally distributed. Friedman test followed by Bonferroni-adjusted Wilcoxon signed-rank test for post hoc analysis was performed to compare image quality and artifact scores.
The mean scores for conspicuity of pancreatic edges (3.36 vs. 2.37), interslice signal homogeneity (3.14 vs. 2.81), presence of ghosting artifacts (3.32 vs. 2.66), susceptibility artifacts (3.06 vs. 2.30), and aliasing artifacts (3.90 vs. 2.34), and overall image quality (3.49 vs. 2.36) were significantly higher in the tilted rDWI than in the rDWI (P < 0.017 for all parameters). The conspicuity score for focal pancreatic lesions tended to be higher in tilted rDWI than in rDWI (2.44 vs. 2.00, P = 0.07).
Tilted rDWI had better image quality and reduced artifacts relative to cDWI and rDWI techniques in the pancreas.
4 TECHNICAL EFFICACY: Stage 2.
尽管已经评估了该技术在脑和脊髓成像中的应用，该技术允许在相位编码方向上不产生混叠伪影的情况下获取高质量的图像，但在胰腺成像中尚未应用具有倾斜二维射频（RF）激发平面的小视野扩散加权成像（rDWI）。
通过倾斜激发平面（倾斜 rDWI）与常规 DWI（cDWI）和不使用倾斜激发平面的 rDWI 相比，评估胰腺的视觉图像质量。
回顾性。
32 名疑似胰胆管疾病患者。
磁场强度/序列：在 3T 下采集的单次激发平面回波成像 DWI（cDWI、rDWI 和倾斜 rDWI）。
由五名放射科医生分析每个 DWI 序列的图像，以比较图像质量（胰腺边缘的清晰度、切片间信号均匀性、整体图像质量和局灶性胰腺病变的清晰度）和伪影（存在模糊或重影伪影、磁化率伪影和混叠伪影）。
进行 Shapiro-Wilk 检验以评估数据是否呈正态分布。采用 Friedman 检验，然后进行事后 Bonferroni 校正的 Wilcoxon 符号秩检验，以比较图像质量和伪影评分。
在倾斜 rDWI 中，胰腺边缘的清晰度（3.36 与 2.37）、切片间信号均匀性（3.14 与 2.81）、重影伪影的存在（3.32 与 2.66）、磁化率伪影（3.06 与 2.30）和混叠伪影（3.90 与 2.34）以及整体图像质量（3.49 与 2.36）的评分均显著高于 rDWI（所有参数 P 值均<0.017）。倾斜 rDWI 中局灶性胰腺病变的清晰度评分倾向于高于 rDWI（2.44 与 2.00，P=0.07）。
与 cDWI 和 rDWI 技术相比，倾斜 rDWI 具有更好的胰腺图像质量和更少的伪影。
4 级技术功效：2 级。
