Use of contrast enhancement in conjunction with magnetic resonance (MR) imaging provides a means to evaluate tissue function, as well as morphology. Moreover, physiologic properties derived from kinetic analysis of dynamic contrast-enhanced data can improve the specificity of MR examinations. In this study, quantitative analysis of microvascular characteristics based on dynamic MR imaging were performed both for malignant and benign lesions using two types of contrast agents (CAs). A new MR macromolecular contrast medium (MMCM), 24 gadolinium-tetraazacyclododecanetetraacetic acid (DOTA)-dendrimer, was found to have a greater ability to distinguish benign from malignant lesions. When a blood pool agent was used, permeability differences in the two types of lesions were the most significant findings among all parameters considered.