Differentiation of Muscular Invasion in Bladder Cancer: Additional Value of Synthetic Magnetic Resonance Imaging.

To evaluate the potential of Synthetic Magnetic Resonance Imaging (SynMRI) in identifying muscular invasion in bladder cancer (BCa), and explore whether there is additional value in combination with the Vesical Imaging-Reporting and Data System (VI-RADS). In this prospective single-center study, pathologically-confirmed BCa were enrolled between May 2023 and November 2023. All participants underwent preoperative multiparametric MRI, including T1/T2 weighted, SynMRI and diffusion-weighted imaging. T1/T2/PD values and apparent diffusion coefficient (ADC) values were compared between muscle invasive (MIBC) and non-invasive (NMIBC) groups. Receiver operating characteristic (ROC) analysis with the variables and their combination was performed to explore the performance of distinguishing the MIBC from NMIBC, and the ROC curves were compared using DeLong's test. A total of 54 BCa patients were enrolled (38 males; NMIBC/MIBC=37/19) and all assessed with VI-RADS without dynamic enhanced imaging (DCE). Compared to NMIBC group, MIBC group had significantly larger diameter, higher VI-RADS score, lower T2 and ADC values (P < 0.05). VI-RADS score and T2 showed independent predictive value in differentiating NMIBC and MIBC. The combined model (T2 + VI-RADS+Diameter) resulted in significantly improved specificity (0.842), sensitivity (0.914), and AUC (0.943), in comparison to VI-RADS or ADC alone (P < 0.05). T2 relaxation time can be easily obtained from SynMRI in routine clinical protocol and assist VI-RADS score system without DCE to improve differentiation performance in identifying NMIBC and MIBC.

Zhang X ，Guo J ，Yun Y ，Shan D ，Yang D ，Xu C ，Chen X ... -  《-》

The Value of Multi-directional High b-Value DWI in the Assessment of Muscular Invasion in Bladder Urothelial Carcinoma: In Comparison with VI-RADS.

To predict the muscular invasion status of bladder urothelial carcinoma (UCB) using quantitative parameters from multi-directional high b-value diffusion-weighted imaging (MDHB-DWI), and compare these parameters with the Vesical Imaging Reporting and Data System (VI-RADS). In this prospective study, patients with pathologically confirmed UCB were enrolled between May 2023 and May 2024. All participants underwent preoperative MRI, including MDHB-DWI and conventional MRI. The average quantitative parameter values of MDHB-DWI (diffusion kurtosis imaging [DKI], diffusion tensor imaging [DTI], mean apparent propagator [MAP] and neurite orientation dispersion and density imaging [NODDI]) and apparent diffusion coefficient (ADC) values were compared between non-muscle invasive (NMIBC) and muscle-invasive (MIBC) groups using the T-test or rank sum test. Quantitative MRI models were developed using multivariate logistic regression analyses based on significant diffusion parameters obtained from MDHB-DWI. Receiver operating characteristic (ROC) curves were plotted, and DeLong's test was applied to compare the area under the curve (AUC) of the model with that of VI-RADS. A total of 76 patients with UCB (56 males; NMIBC/MIBC=51/25) were included. Axial diffusivity (AD) from DKI and mean diffusivity (MD) from DTI were identified as independent predictors for constructing a quantitative MRI model. The AUC of the model was 0.936, significantly outperforming VI-RADS (AUC=0.831) (p = 0.007). DKI-AD and DTI-MD from MDHB-DWI demonstrate a robust ability to differentiate muscular invasion in UCB. Their combination significantly improves diagnostic efficiency compared to VI-RADS.

Zhang X ，Yun Y ，Wang S ，Wang M ，Zhang S ，Yang D ，Chen X ，Xu C ... -  《-》

Prospective Assessment of VI-RADS with Muscle Invasion in Urinary Bladder Cancer and Its Implication on Re-Resection/Restaging TURBT Patients.

Bladder cancer (BCa) diagnosis relies on distinguishing muscle-invasive bladder cancer (MIBC) from non-muscle-invasive bladder cancer (NMIBC) forms. Transurethral resection of the bladder tumor (TURBT) is a standard procedure for initial staging and treatment. The Vesical Imaging-Reporting and Data System (VI-RADS) enhances diagnostic accuracy for muscle invasiveness through advanced imaging techniques, potentially reducing reliance on repeat TURBT and improving patient management. We aimed to evaluate the role of VI-RADS in predicting muscle invasiveness in BCa and its potential to predict adverse pathology in high-risk NMIBC to avoid unnecessary repeat TURBT procedures. In this prospective study, we included 62 patients over the age of 18 years who underwent TURBT. In a secondary phase, patients selected for restaging TURBT (re-TURBT) were included, but those with T2 tumors or low-risk NMIBC were excluded. Multiparametric magnetic resonance imaging (MRI) examinations were scored by a radiologist using the VI-RADS 5 method, while a pathologist analyzed TURBT and re-TURBT samples for accurate staging. Statistical analysis evaluated the role of VI-RADS in BCa staging. The VI-RADS score was the only predictive factor for muscle invasion in multivariate analysis. Setting the VI-RADS score at >3 resulted in the highest sensitivity, specificity, and diagnostic accuracy, with values of 67.0%, 89.0%, and 78%, respectively. The receiver operating characteristic area under the curve score for VI-RADS for muscle invasion was 85% for stage Ta, 61% for stage T1, and 88% for stage T2, which shows the utility of VI-RADS in the predictiveness of MIBC/NMIBC. VI-RADS is effective in stratifying BCa patients by predicting muscle invasiveness and identifying NMIBC cases that may not need repeat TURBT.

Kural S ，Pathak AK ，Singh S ，Jain G ，Yadav M ，Agarwal S ，Kumar I ，Gupta M ，Singh Y ，Kumar U ，Trivedi S ，Sankhwar SN ，Das P ，Kumar L ... -  《-》

Comparative diagnostic performance of VI-RADS based on biparametric and multiparametric MRI in predicting muscle invasion in bladder cancer.

Vesical Imaging-Reporting and Data System (VI-RADS) based on multiparametric magnetic resonance imaging (mp-MRI) performed well in diagnosing muscle-invasive bladder cancer (MIBC). However, certain cases may present challenges in determining the final VI-RADS score using only T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) sequences, especially in the absence of dynamic contrast-enhanced (DCE) imaging. This study aims to evaluates whether biparametric MRI (bp-MRI) achieve comparable diagnostic performance to mp-MRI for predicting MIBC and seeks to identify the most suitable bp-MRI criterion by establishing four specific conditions based on T2WI and DWI. A retrospective analysis was conducted on 447 patients who underwent preoperative mp-MRI. Images were evaluated according to the VI-RADS protocol by three independent readers. In the bp-DWI and bp-DWI Plus criteria, DWI was the primary sequence used for lesion assessment, while T2WI was the primary sequence for bp-T2WI and bp-T2WI Plus criteria. The Plus criteria (bp-DWI Plus and bp-T2WI Plus) assigned a final VI-RADS score of 4 when both T2WI and DWI scores were 3. The gold standard for diagnosis was histopathological evaluation after surgery. Diagnostic performance was evaluated by comparing the area under the curve (AUC), sensitivity, specificity, and inter-reader agreement using Cohen's kappa analysis. Among 447 patients, 304 confirmed as NMIBC and 143 as MIBC. The kappa values were 0.876, 0.873, 0.873, 0.642, and 0.642 for mp-MRI, bp-DWI, bp-DWI Plus, bp-T2WI, and bp-T2WI Plus, respectively, when VI-RADS cutoff > 2. Similarly, when cutoff > 3, the kappa values were 0.848, 0.811, 0.873, 0.811, and 0.873. No significant differences were observed between mp-MRI and bp-DWI (AUC: 0.916 vs. 0.912, p = 0.498), but mp-MRI and bp-DWI had higher AUCs compared to bp-DWI Plus, bp-T2WI, and bp-T2WI Plus. Both mp-MRI and bp-DWI demonstrate excellent performance in predicting MIBC, with bp-DWI being an alternative to mp-MRI. retrospectively.

Liu P ，Cai L ，Jiang L ，Chen H ，Cao Q ，Bai K ，Bai R ，Wu Q ，Yang X ，Lu Q ... -  《BMC MEDICAL IMAGING》

Use of Multiparametric and Biparametric Magnetic Resonance Imaging in Bladder Cancer Staging: Prospective Observational Study and Analysis of Radiologist Learning Curve.

Piramide F ，Sica M ，Fondello G ，Mesterca G ，Ferrando L ，Ziani N ，Ortenzi M ，Grosso G ，Desana B ，Frattoni P ，De Cillis S ，Piana A ，Amparore D ，Checcucci E ，Fiori C ，Cirillo S ，Porpiglia F ，Manfredi M ... -  《Journal of Clinical Medicine》