The Vesical Imaging-Reporting and Data System (VI-RADS) has demonstrated effectiveness in predicting muscle invasion in bladder cancer before treatment. The urgent need currently is to evaluate the muscle invasion status after neoadjuvant chemotherapy (NAC) for bladder cancer. This study aims to ascertain the accuracy of VI-RADS in detecting muscle invasion post-NAC treatment and assess its diagnostic performance across readers with varying experience levels. In this retrospective study, patients with muscle-invasive bladder cancer who underwent magnetic resonance imaging (MRI) after NAC from September 2015 to September 2018 were included. VI-RADS scores were independently assessed by five radiologists, consisting of three experienced in bladder MRI and two inexperienced radiologists. Comparison of VI-RADS scores was made with postoperative histopathological diagnosis. Receiver operating characteristic curve analysis (ROC) was used for evaluating diagnostic performance, calculating sensitivity, specificity, and area under ROC (AUC)). Interobserver agreement was assessed using the weighted kappa statistic. The final analysis included 46 patients (mean age: 61 years ± 9 [standard deviation]; age range: 39–70 years; 42 men). The pooled AUC for predicting muscle invasion was 0.945 (95% confidence interval (CI): 0.893–0.977) for experienced readers, and 0.910 (95% CI: 0.831–0.959) for inexperienced readers, and 0.932 (95% CI: 0.892–0.961) for all readers. At an optimal cut-off value ≥ 4, pooled sensitivity and specificity were 74.1% (range: 66.0–80.9%) and 94.1% (range: 88.6–97.7%) for experienced readers, and 63.9% (range: 59.6–68.1%) and 86.4% (range: 84.1–88.6%) for inexperienced readers. Interobserver agreement ranged from substantial to excellent between all readers (k = 0.79–0.92). VI-RADS accurately assesses muscle invasion in bladder cancer patients after NAC and exhibits good diagnostic performance across readers with different experience levels.

中文翻译：

---

膀胱癌新辅助化疗后膀胱影像报告及数据系统的MRI评估

膀胱成像报告和数据系统 (VI-RADS) 已证明在治疗前预测膀胱癌肌肉侵袭的有效性。目前迫切需要评估膀胱癌新辅助化疗（NAC）后的肌肉侵袭状况。本研究旨在确定 VI-RADS 在检测 NAC 治疗后肌肉侵袭方面的准确性，并评估其在不同经验水平的读者中的诊断性能。在这项回顾性研究中，纳入了 2015 年 9 月至 2018 年 9 月在 NAC 后接受磁共振成像 (MRI) 的肌层浸润性膀胱癌患者。 VI-RADS 评分由五名放射科医生独立评估，其中三名具有膀胱 MRI 经验的放射科医生和两名缺乏经验的放射科医生。将VI-RADS评分与术后组织病理学诊断进行比较。受试者工作特征曲线分析 (ROC) 用于评估诊断性能、计算灵敏度、特异性和 ROC 下面积 (AUC)。使用加权 kappa 统计量评估观察者间的一致性。最终分析包括 46 名患者（平均年龄：61 岁±9 [标准差]；年龄范围：39-70 岁；42 名男性）。对于有经验的读者，预测肌肉侵袭的汇总 AUC 为 0.945（95% 置信区间 (CI)：0.893–0.977），对于没有经验的读者为 0.910（95% CI：0.831–0.959），对于没有经验的读者，为 0.932（95% CI：0.892– 0.961）适用于所有读者。在最佳截止值≥4时，有经验的读者的汇总敏感性和特异性分别为74.1%（范围：66.0-80.9%）和94.1%（范围：88.6-97.7%），以及63.9%（范围：59.6-68.1%） ），对于没有经验的读者，为 86.4%（范围：84.1–88.6%）。所有读者之间的观察者间一致性范围从显着到极好 (k = 0.79–0.92)。 VI-RADS 可以准确评估 NAC 后膀胱癌患者的肌肉侵犯，并在不同经验水平的读者中表现出良好的诊断性能。