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

Abstract

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.

Figures

Figure 1.

Diagnostic accuracy of MRI sequences in muscle invasion

Figure 2.

Diagnostic accuracy of VI-RADS score. VI-RADS, vesical imagingreporting and data system

Figure 3.

61-year-old male patient with history of terminal hematuria. High resolution axial (a) and sagittal (b) T2WI images shows non-muscle invasive right posterolateral U.B. polypoidal lesion not disrupting the hypointense detrusor lining (arrows). DW image (c) and ADC map image (d) show highly restricted diffusion mass with facilitated diffusion of muscle layer exclude muscle invasion (arrow) and low ADC value about 0.8 × 10–3 mm2/s denoting malignant nature. DCE-MRI (e) non-contrast subtracted image and (f) early arterial phase image are displaying early intense enhancement of the mass with no enhancement of muscle layer exclude muscle invasion (arrow). Multiparameteric MRI are consistent with non-muscle invasive bladder cancer (Stage T1) and VI-RADS II, which confirmed histopathologically. ADC, apparent diffusioncoefficient; T2WI,T2 weightedimaging; VI-RADS, vesical imaging reporting and data system.

Figure 4.

A 54-year-old male patient with history of recurrent hematuria. High resolution axial (a) and sagittal (b) T2WI images shows muscle-invasive left anterolateral U.B. polypoidal lesion disrupting the underneath hypointense detrusor lining, with no extension to perivesical fat (arrows). DW image (c) and ADC map image (d) show highly restricted diffusion of mass with facilitated diffusion of muscle layer exclude muscle invasion (arrow) and low ADC value about 0.7 × 10–3 s/mm2 denoting malignant nature, DCE-MRI (e) non-contrast subtracted image and (f) early arterial phase image are displaying early intense enhancement of the mass with interrupted enhancement of muscle layer denoting muscle invasion (arrow). Multiparameteric MRI are consistent with muscle-invasive bladder cancer (Stage T2) and VI-RADS IV which confirmed histopathologically. ADC, apparent diffusioncoefficient; T2WI,T2 weightedimaging; VI-RADS, vesical imaging reporting and data system.