Department of Radiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Eur J Radiol. 2021 Mar;136:109486. doi: 10.1016/j.ejrad.2020.109486. Epub 2020 Dec 31.
To compare the image quality of the reduced field-of-view (rFOV) diffusion-weighted imaging (DWI) with the full field-of-view (fFOV) DWI in the assessment of bladder cancer (BC); and to explore the possible superiority of bi-planar (axial and sagittal) rFOV DWI over single planar fFOV DWI in predicting muscle-invasiveness of BC.
This retrospective study analyzed 61 patients with BC who underwent DWI sequences including axial fFOV DWI, axial rFOV DWI, and sagittal rFOV DWI. Qualitative and quantitative image quality assessment were compared between axial fFOV DWI and rFOV DWI sequences. The tumor with its base could be clearly displayed on DWI was defined as the evaluable lesion, and the number of evaluable lesions detected from single axial fFOV DWI, axial rFOV DWI, sagittal rFOV DWI, and bi-planar rFOV DWI sequences was recorded and compared. The apparent diffusion coefficient (ADC) was compared between non-muscular-invasive bladder cancer (NMIBC) and muscular-invasive bladder cancer (MIBC) based on the sequences of axial fFOV DWI and rFOV DWI, respectively. Vesical Imaging-Reporting and Data System (VI-RADS) was introduced to evaluate the overall risk of muscle-invasiveness of BC and receiver operating characteristic (ROC) curve analysis was applied to assess the diagnostic performance.
The contrast-to-noise ratio (CNR) of the rFOV DWI was significantly higher than that of fFOV DWI (p < 0.01), while the signal-to-noise ratio (SNR) was significantly lower than that of fFOV DWI (p < 0.01). The subjective score of rFOV DWI was significantly higher than that of fFOV DWI (p < 0.01). The ADC value of the MIBC group was significantly lower than that of the NMIBC in both rFOV DWI and fFOV DWI (all p < 0.01). The number of evaluable lesions detected from the bi-planar rFOV DWI was significantly higher than that detected from the single axial fFOV DWI, axial rFOV DWI, and sagittal rFOV DWI (all p < 0.01). VI-RADS based on the bi-planar rFOV DWI offered high predictive power (the area under the ROC curve, 0.946) for predicting the presence of muscle-invasiveness of BC.
Bi-planar rFOV DWI may provide more diagnostic confidence than the single planar DWI for predicting the presence of muscle-invasiveness in BC, with improved image quality over the fFOV DWI.
比较低（rFOV）视野扩散加权成像（DWI）与全视野（fFOV）DWI 在膀胱癌（BC）评估中的图像质量，并探讨双平面（轴位和矢状位）rFOV DWI 在预测 BC 肌肉浸润方面是否优于单平面 fFOV DWI。
本回顾性研究纳入了 61 例 BC 患者，他们均接受了包括轴位 fFOV DWI、轴位 rFOV DWI 和矢状位 rFOV DWI 在内的 DWI 序列检查。比较了轴位 fFOV DWI 和 rFOV DWI 序列的定性和定量图像质量评估。在 DWI 上能够清晰显示肿瘤及其基底部的病灶被定义为可评估病灶，并记录和比较了单轴位 fFOV DWI、轴位 rFOV DWI、矢状位 rFOV DWI 和双平面 rFOV DWI 序列检测到的可评估病灶数量。基于轴位 fFOV DWI 和 rFOV DWI 序列，分别比较非肌层浸润性膀胱癌（NMIBC）和肌层浸润性膀胱癌（MIBC）的表观扩散系数（ADC）。引入膀胱成像报告和数据系统（VI-RADS）评估 BC 肌肉浸润的总体风险，并应用受试者工作特征（ROC）曲线分析评估诊断性能。
rFOV DWI 的对比噪声比（CNR）显著高于 fFOV DWI（p<0.01），而信噪比（SNR）显著低于 fFOV DWI（p<0.01）。rFOV DWI 的主观评分显著高于 fFOV DWI（p<0.01）。rFOV DWI 和 fFOV DWI 中 MIBC 组的 ADC 值均显著低于 NMIBC 组（均 p<0.01）。双平面 rFOV DWI 检测到的可评估病灶数量明显多于单轴位 fFOV DWI、轴位 rFOV DWI 和矢状位 rFOV DWI（均 p<0.01）。基于双平面 rFOV DWI 的 VI-RADS 对预测 BC 肌肉浸润的存在具有较高的预测能力（ROC 曲线下面积，0.946）。
与单平面 DWI 相比，双平面 rFOV DWI 可能为预测 BC 肌肉浸润提供更多诊断信心，并且图像质量优于 fFOV DWI。
