Value of Dynamic Contrast-Enhanced MRI and Correlation with Tumor Angiogenesis in Bladder Cancer

The aim of this study was to investigate dynamic contrast-enhanced MRI (DCE-MRI) for the noninvasive measurement of bladder cancer angiogenesis by correlation with microvessel density, histologic grade, and tumor staging, and to predict the outcome of local recurrence. Twenty-four patients with bladder cancer were examined using DCE-MRI. Hemodynamic parameters obtained by DCE-MRI included peak time enhancement in the first minute (E(max/1)) after contrast administration, second minute (E(max/2)), third minute (E(max/3)), fourth minute (E(max/4)), and fifth minute (E(max/5)), and the steepest slope. Microvessel density was identified by immunostaining of endothelial cells using FVIII-related antigen. The Mann-Whitney U test, multivariate discriminant analysis, Spearman's correlation coefficient, and analysis of variance were used for statistical analysis. Correlation was seen between DCE-MRI parameters (E(max/1) and steepest slope) and microvessel density (p < 0.05). E(max/1) and steepest slope were found to have a statistically significant correlation with histologic grade (p < 0.05 and p < 0.01, respectively). A significant difference was seen between groups of patients with and without local recurrence with regard to two of the DCE-MRI parameters (p < 0.05 for E(max/1) and E(max/2)). The contrast enhancement patterns on DCE-MRI are influenced by tumor angiogenesis, as reflected by elevated microvessel density expression. Therefore, they are valuable indicators for assessing tumor angiogenic activity and tumor neovascularization in bladder cancers.