The addition of gadolinium contrast agent on MRI has been found to improve the accuracy of local staging for bladder cancer. In a prospective study by Daneshmand et al [61], 122 patients were examined using contrast- enhanced MRI, which had an 88% sensitivity, a 48% specificity, and a 74% accuracy in distinguishing organ- confined from non-organ-confined bladder cancer and a 41% sensitivity, a 92% specificity, and an 80% accuracy in detecting positive nodal disease. Moderate interobserver agreement was found for T and N staging, consistent with other studies [53,54]. Other studies demonstrated the sensitivity and specificity of MRI in distinguishing NMIBC from MIBC ranging from 78% to 98% and 82% to 100% and the sensitivity and specificity for distinguishing organ-confined from non-organ-confined bladder tumors ranging from 90% to 94% and 60% to 94%, respectively [51-54]. Multiparametric MRI, which combines dynamic contrast-enhanced imaging with DWI and T2-weighted imaging, is likely the most optimal MRI technique for local staging of bladder cancer [48,55]. The standardization of bladder cancer staging with multiparametric MRI is facilitated by the VI-RADS scoring system, which was introduced in 2018 [56]. The VI-RADS uses a 5-point scoring system to estimate the likelihood of detrusor muscle invasion, a poor prognosis indicator that requires radical surgery. Wang et al [57] assessed the ability of VI-RADS score to detect MIBC in a group of patients who had multiparametric MRI before surgery. They concluded that VI-RADS effectively predict the likelihood of detrusor muscle invasion in bladder cancer and should be considered for evaluation before surgery.
Pretreatment Staging of Urothelial Cancer. The addition of gadolinium contrast agent on MRI has been found to improve the accuracy of local staging for bladder cancer. In a prospective study by Daneshmand et al [61], 122 patients were examined using contrast- enhanced MRI, which had an 88% sensitivity, a 48% specificity, and a 74% accuracy in distinguishing organ- confined from non-organ-confined bladder cancer and a 41% sensitivity, a 92% specificity, and an 80% accuracy in detecting positive nodal disease. Moderate interobserver agreement was found for T and N staging, consistent with other studies [53,54]. Other studies demonstrated the sensitivity and specificity of MRI in distinguishing NMIBC from MIBC ranging from 78% to 98% and 82% to 100% and the sensitivity and specificity for distinguishing organ-confined from non-organ-confined bladder tumors ranging from 90% to 94% and 60% to 94%, respectively [51-54]. Multiparametric MRI, which combines dynamic contrast-enhanced imaging with DWI and T2-weighted imaging, is likely the most optimal MRI technique for local staging of bladder cancer [48,55]. The standardization of bladder cancer staging with multiparametric MRI is facilitated by the VI-RADS scoring system, which was introduced in 2018 [56]. The VI-RADS uses a 5-point scoring system to estimate the likelihood of detrusor muscle invasion, a poor prognosis indicator that requires radical surgery. Wang et al [57] assessed the ability of VI-RADS score to detect MIBC in a group of patients who had multiparametric MRI before surgery. They concluded that VI-RADS effectively predict the likelihood of detrusor muscle invasion in bladder cancer and should be considered for evaluation before surgery.