Background

Diffusion-weighted imaging (DWI) has shown great value in rectal cancer imaging. However, traditional DWI with echo-planar imaging (DW-EPI) often suffers from geometrical distortions. We applied a three-dimensional diffusion-prepared stimulated-echo turbo spin-echo sequence (DPsti-TSE), allowing geometrically undistorted rectal DWI. We compared DPsti-TSE with DW-EPI for locally advanced rectal cancer DWI.

Methods

For 33 prior-to-treatment patients, DWI images of the rectum were acquired with DPsti-TSE and DW-EPI at 3 T using b-values of 200 and 1000 s/mm². Two radiologists conducted a blinded scoring of the images considering nine aspects of image quality and anatomical quality. Tumour apparent diffusion coefficient (ADC) and distortions were compared quantitatively.

Results

DPsti-TSE scored significantly better than DW-EPI in rectum distortion (p = 0.005) and signal pileup (p = 0.001). DPsti-TSE had better tumour Dice similarity coefficient compared to DW-EPI (0.84 versus 0.80, p = 0.010). Tumour ADC values were higher for DPsti-TSE compared to DW-EPI (1.47 versus 0.86 × 10^-3 mm²/s, p < 0.001). Radiologists scored DPsti-TSE significantly lower than DW-EPI on aspects of overall image quality (p = 0.001), sharpness (p < 0.001), quality of fat suppression (p < 0.001), tumour visibility (p = 0.009), tumour conspicuity (p = 0.010) and rectum wall visibility (p = 0.005).

Conclusions

DPsti-TSE provided geometrically less distorted rectal cancer diffusion-weighted images. However, the image quality of DW-EPI over DPsti-TSE was referred on the basis of several image quality criteria. A significant bias in tumour ADC values from DPsti-TSE was present. Further improvements of DPsti-TSE are needed until it can replace DW-EPI.

中文翻译：

---

局部晚期直肠癌：3D扩散准备的刺激回声涡轮自旋回声与2D扩散加权的回声平面成像。

背景

扩散加权成像（DWI）在直肠癌成像中显示出巨大的价值。但是，传统的具有回波平面成像（DW-EPI）的DWI通常会遭受几何失真。我们应用三维扩散准备刺激回波涡轮自旋回波序列（DPsti-TSE），允许几何未变形的直肠DWI。我们比较了DPsti-TSE与DW-EPI治疗局部晚期直肠癌DWI。

方法

对于33位接受治疗的患者，在3 T时使用bsti值200和1000 s / mm ²用DPsti-TSE和DW-EPI采集了直肠DWI图像。考虑到图像质量和解剖学质量的九个方面，两名放射科医生对图像进行了盲目评分。定量比较了肿瘤的表观扩散系数（ADC）和畸变。

结果

DPsti-TSE在直肠畸变（p = 0.005）和信号堆积（p = 0.001）方面的得分明显优于DW-EPI 。与DW-EPI相比，DPsti-TSE具有更好的肿瘤Dice相似系数（0.84对0.80，p = 0.010）。与DW-EPI相比，DPsti-TSE的肿瘤ADC值更高（1.47对0.86×10 ^-3 mm ² / s，p < 0.001）。放射科医生在整体图像质量（p = 0.001），清晰度（p < 0.001），脂肪抑制质量（p < 0.001），肿瘤可见度（p =0.009），肿瘤显眼度（p = 0.010）和直肠壁可见度（p = 0.005）。

结论

DPsti-TSE提供了较少几何变形的直肠癌扩散加权图像。但是，DW-EPI在DPsti-TSE上的图像质量是根据几种图像质量标准得出的。存在来自DPsti-TSE的肿瘤ADC值的显着偏差。在可以替代DW-EPI之前，需要进一步改进DPsti-TSE。