## 10 Future Perspectives of VI-RADS  
The role of VI-RADS in the management of BC is still being extensively investigated. In view of its versatility, the reporting system could potentially support disease management at every disease stage. One major line of research is represented by the possibility of mpMRI to revisit the role of extensive TURBT in clearly muscle-invasive BC [49], with preliminary reports confirming the feasibility of such a strategy [20]. Patients with a VI-RADS score 5 disease might potentially avoid the morbidity of extensive primary resections in favour of sampling-TURBT for histology [50]. Concurrently, VI-RADS have also shown high concordance to conventional re-TURBT results in high-risk NMIBC, and a VI-RADS score 2 was identified as a clinical predictor of non-invasive disease at the second resection while VI-RADS cut-off of 3 as a predictor of understaged MIBC at TURBT [51]. These results hint at a possible practice-changing implementation of VI-RADS as a preoperative stratification test in the management of a highly prevalent disease such as NMIBC, granting a considerable reduction in patient morbidity and a reduction in treatment delay in patients harbouring MIBC. Further refinement of mpMRI performance/quality and validation of VI-RADS in this specific scenario has been advocated. MRI also appears to be promising in detecting therapeutic response to chemotherapy or radiotherapy. Preliminary reports have shown the feasibility of reporting vessel mpMRI in patients completing nac for MIBC according to the nacVI-RADS scoring system. nacVI-RADS were successfully used to assess radiological response to nac, the presence of residual disease and the infiltration of the muscularis propria in a pilot cohort of patients undergoing radical cystectomy [43]. DWI, and ADC value quantification was also used to predict tumour aggressiveness and sensitivity of chemoradiotherapy, while DCE value quantification adequately supported the detection of residual disease from post-nac effects [52; 53; 54]. Overall possible implementation of diffusion- and contrast-based cut-off values in standardised mpMRI reporting systems could further enhance the versatility of the tool in the setting of neoadjuvant chemotherapy. However, prospective large-cohort studies are still needed to validate their clinical use prior to neoadjuvant chemotherapy and selection of appropriate bladder-cancer treatment strategies. Biparametric MRI carries the promising advantages of a contrast-free imaging protocol, consisting in shorter image acquisition and the elimination of possible adverse events related to the administration of intravenous contrast medium. Multivariate logistic regression analysis showed that only T2w VI-RADS scores were independent predictors of detrusor muscle invasion in a series of 57 patients receiving an mpMRI for BC, proving that contrast medium may not be necessary for the local staging of BC [38]. [PERSON] et al. presented a diffusion-based fractional-order calculus diffusion model and combined it to a simplified biparametric VI-RADS to achieve high diagnostic performance in MIBC detection [55], providing further evidence that contrast-free MRI protocols may provide comparable diagnostic accuracy to mpMRI for MIBC detection [40]. The prospective head-to-head assessment of bp- vs. mpMRI in BC diagnostics may provide definitive answers on the added value of intravenous contrast medium administration. Despite VI-RADS score promises to be very useful in clinical practice, there are some limitations at the present development state which should be considered. Primarily, VI-RADS score was initially developed in untreated patients to differentiate NMIBC from MIBC, hence its application in treated patients should be investigated further. VI-RADS score does not include some radiologically independent predictors of muscle invasion, such as number and location of the lesions or urethral infiltration.