Visual MRI T-category versus VI-RADS evaluation from multiparametric MRI in the detection of muscle-invasion in patients with suspected bladder cancer: single centre registered clinical trial (MIB-trial)

Abstract Objectives (1) To investigate whether a contrast-free biparametric MRI (bp-MRI) including T2-weighted images (T2W) and diffusion-weighted images (DWI) can be considered an accurate alternative to the standard multiparametric MRI (mp-MRI), consisting of T2, DWI, and dynamic contrast-enhanced (DCE) imaging for the muscle-invasiveness assessment of bladder cancer (BC), and (2) to evaluate how the diagnostic performance of differently experienced readers is affected according to the type of MRI protocol. Methods Thirty-eight patients who underwent a clinically indicated bladder mp-MRI on a 3-T scanner were prospectively enrolled. Trans-urethral resection of bladder was the gold standard. Two sets of images, set 1 (bp-MRI) and set 2 (mp-MRI), were independently reviewed by four readers. Descriptive statistics, including sensitivity and specificity, were calculated for each reader. Receiver operating characteristic (ROC) analysis was performed, and the areas under the curve (AUCs) were calculated for the bp-MRI and the standard mp-MRI. Pairwise comparison of the ROC curves was performed. Results The AUCs for bp- and mp-MRI were respectively 0.91–0.92 (reader 1), 0.90 (reader 2), 0.95–0.90 (reader 3), and 0.90–0.87 (reader 4). Sensitivity was 100% for both protocols and specificity ranged between 79.31 and 89.66% and between 79.31 and 83.33% for bp-MRI and mp-MRI, respectively. No significant differences were shown between the two MRI protocols (p > 0.05). No significant differences were shown accordingly to the reader’s experience (p > 0.05). Conclusions A bp-MRI protocol consisting of T2W and DWI has comparable diagnostic accuracy to the standard mp-MRI protocol for the detection of muscle-invasive bladder cancer. The experience of the reader does not significantly affect the diagnostic performance using VI-RADS. Key Points • The contrast-free MRI protocol shows a comparable accuracy to the standard multiparametric MRI protocol in the bladder cancer muscle-invasiveness assessment. • VI-RADS classification helps non-expert radiologists to assess the muscle-invasiveness of bladder cancer. • DCE should be carefully interpreted by less experienced readers due to inflammatory changes representing a potential pitfall.

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Multiparametric MRI in differentiation between muscle invasive and non-muscle invasive urinary bladder cancer with vesical imaging reporting and data system (VI-RADS) application

British Journal of Radiology ◽

10.1259/bjr.20190401 ◽

2019 ◽

Vol 92 (1104) ◽

pp. 20190401 ◽

Cited By ~ 15

Author(s):

Marwa Makboul ◽

Shimaa Farghaly ◽

Islam F. Abdelkawi

Keyword(s):

Bladder Cancer ◽

Interobserver Agreement ◽

Urinary Bladder Cancer ◽

Multiparametric Mri ◽

Invasive Bladder Cancer ◽

Non Invasive ◽

Contrast Enhanced ◽

Muscle Invasive ◽

Muscle Invasion ◽

Contrast Enhanced Mri

Objective: To evaluate role of multiparametric MRI (mp-MRI) in differentiation between invasive and non-invasive bladder cancer and accuracy of vesical imaging reporting and data system (VI-RADS) score. Methods and materials: 50 patients diagnosed as cancer bladder were enrolled in this study, mp-MRI including conventional (T1 weighted imaging and high resolution T2 weighted imaging) and functional sequences (diffusion-weighted imaging and dynamic contrast enhanced-MRI) were done, all data were regrouped to evaluate the accuracy of each separate sequence and mp-MRI in distinguishing non-muscle invasive from muscle-invasive tumors, with VI-RADS score application and comparison with pathological findings, then interobserver agreement for detection of muscle invasion according to mp-MRI and VI-RADS scoring system findings was calculated. Results: Diagnostic accuracy of mp-MRI in differentiation between muscle invasive and non-muscle invasive bladder cancer was (84%) with highest sensitivity (78%), very good agreement between mp-MRI and histopathological data (k = 0.87), and highest area under curve (AUC) reaching 0.83, dynamic contrast enhanced-MRI sequence showed the highest accuracy in muscle invasion detection by (88%), with highest AUC 0.83. Diagnostic accuracy of VI-RADS score in detection of muscle invasion was 84%, with specificity and negative predictive value of 88% and AUC was 0.83. Interobserver agreement was strong as regard diagnostic performance of mp-MRI and VI-RADS scoring for detection of muscle invasion reaching (K = 0.82, p < 0.001) and (K = 0.87, p < 0.001) respectively. Conclusion: mp-MRI is considered as comprehensive and effective tool for determination of muscle invasion in cases of urinary bladder cancer. Also VI-RADS scoring system can accurately differentiate between invasive and non-invasive bladder cancer. Advances in knowledge: The VI-RADS system was recently suggested for the uniform evaluation of muscle invasion in cancer bladder by mp-MRI. In this paper, we applied this system to 50 cases to evaluate its ease and compared the results with the histopathological findings for evaluation of its accuracy.

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