The enhanced permeability and retention (EPR) effect depends on nanoparticle properties and tumor/vessel conditions. We aimed to develop a tumor vasculature evaluation method and high-resolution nanoparticle-delivery imaging technique using magnetic resonance micro-imaging technology and a gadolinium (Gd)-dendron assembled liposomal contrast agent. We achieved 50-μm isotropic MR angiography with clear visualization of tumor micro-vessel structure. The Gd-liposome-enhanced MR micro-imaging revealed differences in the vascular structures between two different types of grafted mice models. The MR micro-imaging methods facilitate the evaluation of intratumoral vascularization patterns, the quantitative assessment of vascular-properties that alter tumor malignancy, particle retentivity, and the effects of treatment.