Objective To explore the value of vesical imaging reporting and data system(VI-RADS)combined with absolute tumor-wall contact length(ABTCL)and actual tumor-wall contact length(ACTCL)in diagnosing muscle invasive bladder cancer(MIBC).Methods The MRI data of 113 patients with pathologically confirmed bladder cancer(BCa)were analyzed retrospectively.All patients underwent conventional MRI,diffusion weighted imaging(DWI)and dynamic contrast enhanced(DCE)MRI before sur-gery.Two radiologists independently evaluated MRI images based on VI-RADS score,and measured quantitative parameters,inclu-ding ABTCL and ACTCL.The Chi-square test was used to compare the difference of VI-RADS scores between MIBC and non-mus-cle invasive bladder cancer(NMIBC).Quantitative parameters between MIBC and NMIBC were compared by Mann-Whitney U test.The receiver operating characteristic(ROC)curve was used to evaluate the diagnostic value of VI-RADS,quantitative parameters and VI-RADS combined with quantitative parameters in the diagnosis of MIBC.Results VI-RADS,ABTCL and ACTCL had significant differences between MIBC and NMIBC(P＜0.05).The area under the curve(AUC)for VI-RADS,ABTCL and ACTCL in diagno-sing MIBC were 0.89,0.76 and 0.77,respectively.There was no significant difference between the AUC for ABTCL and ACTCL(P＞0.05).The AUC for VI-RADS combined with ABTCL or ACTCL in diagnosing MIBC was 0.93,higher than that of only VI-RADS(P＜0.05).Conclusion The combination of VI-RADS with either ABTCL or ACTCL can effectively improve the diagnostic performance of MIBC.ABTCL obtainedby linear measurement is easier to implement in clinical practice than ACTCL obtained by curved measurement.