Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, USA; Department of Radiology, Keio University School of Medicine, Tokyo, Japan.
Department of Radiology, Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Groningen, The Netherlands.
Eur Urol Focus. 2024 Jan;10(1):131-138. doi: 10.1016/j.euf.2023.08.004. Epub 2023 Aug 25.
The diagnostic performance of contrast medium-free biparametric magnetic resonance imaging (bpMRI; combining T2-weighted imaging [T2WI] and diffusion-weighted imaging [DWI]) for evaluating variant-histology urothelial carcinoma (VUC) remains unknown.
To compare the diagnostic performance of bpMRI and multiparametric MRI (mpMRI; combining T2WI, DWI, and dynamic contrast-enhanced MRI]) for assessing muscle invasion of VUC.
DESIGN, SETTING, AND PARTICIPANTS: This multi-institution retrospective analysis included 118 patients with pathologically verified VUC who underwent bladder mpMRI before transurethral bladder tumor resection between 2010 and 2019.
Three board-certified radiologists separately evaluated two sets of images, set 1 (bpMRI) and set 2 (mpMRI), in accordance with the Vesical Imaging Reporting and Data System (VI-RADS). The histopathology results were utilized as a reference standard. Receiver operating characteristic curve analysis, Z test, and Wald test were used to assess diagnostic abilities.
Sixty-six (55.9%) and 52 (44.1%) of the 118 patients with VUC included in the analysis (mean age, 71 ± 10 yr; 88 men) had muscle-invasive bladder cancer (MIBC) and non-MIBC, respectively. For the diagnosis of MIBC, the areas under the curve for bpMRI were significantly smaller than those for mpMRI (0.870-0.884 vs 0.902-0.923, p < 0.05). The sensitivity of bpMRI was significantly lower than that of mpMRI for all readers with a VI-RADS cutoff score of 4 (65.2-66.7% vs 77.3-80.3%, p < 0.05). The specificity of bpMRI and mpMRI did not differ significantly for all readers (88.5-90.4 vs 88.5-92.3, p > 0.05). A limitation of the study is the limited sample size because of the rarity of VUC.
In patients with VUC, on applying VI-RADS, the diagnostic results of bpMRI were inferior to those of mpMRI for evaluating muscle invasion. Therefore, mpMRI-based methods are recommended for evaluating muscle invasiveness of VUC.
Contrast medium-free biparametric magnetic resonance imaging (bpMRI)-based Vesical Imaging Reporting and Data System (VI-RADS) can accurately diagnose pure urothelial carcinomas, similar to conventional multiparametric magnetic resonance imaging-based VI-RADS. However, bpMRI-based VI-RADS may misdiagnose muscle invasiveness of urothelial carcinoma with variant histology, particularly when its cutoff score is 4.
对比增强剂-free 双参数磁共振成像（bpMRI；结合 T2 加权成像 [T2WI] 和扩散加权成像 [DWI]）在评估变异型尿路上皮癌（VUC）方面的诊断性能尚不清楚。
比较 bpMRI 和多参数 MRI（mpMRI；结合 T2WI、DWI 和动态对比增强 MRI）评估 VUC 肌层浸润的诊断性能。
设计、地点和参与者：本多机构回顾性分析纳入了 118 例经病理证实的 VUC 患者，这些患者在 2010 年至 2019 年间接受了经尿道膀胱肿瘤切除术之前进行了膀胱 mpMRI。
三位经过董事会认证的放射科医生分别根据膀胱成像报告和数据系统（VI-RADS）评估了两组图像，第 1 组（bpMRI）和第 2 组（mpMRI）。组织病理学结果被用作参考标准。使用受试者工作特征曲线分析、Z 检验和 Wald 检验来评估诊断能力。
在分析的 118 例 VUC 患者中（平均年龄 71 ± 10 岁；88 名男性），66 例（55.9%）和 52 例（44.1%）分别患有肌层浸润性膀胱癌（MIBC）和非 MIBC。对于 MIBC 的诊断，bpMRI 的曲线下面积明显小于 mpMRI（0.870-0.884 与 0.902-0.923，p<0.05）。对于所有读者，bpMRI 的灵敏度明显低于 VI-RADS 截断值为 4 时的 mpMRI（65.2-66.7%与 77.3-80.3%，p<0.05）。对于所有读者，bpMRI 和 mpMRI 的特异性没有显著差异（88.5-90.4%与 88.5-92.3%，p>0.05）。该研究的一个局限性是由于 VUC 的罕见性，样本量有限。
在 VUC 患者中，应用 VI-RADS 时，bpMRI 对评估肌肉浸润的诊断结果不如 mpMRI。因此，推荐使用基于 mpMRI 的方法来评估 VUC 的肌肉浸润程度。
基于对比增强剂-free 双参数磁共振成像（bpMRI）的膀胱成像报告和数据系统（VI-RADS）可以准确诊断纯尿路上皮癌，与传统的基于多参数磁共振成像的 VI-RADS 相似。然而，bpMRI 基于 VI-RADS 可能会错误诊断具有变异组织学的尿路上皮癌的肌肉浸润，特别是当截断值为 4 时。
