A ferumoxytol-enhanced MRA technique using Ultrashort Time-to-Echo (UTE) sequences is demonstrated for kidney vasculature mapping and renal mass assessment. The blood volume (BV) map is calculated by scaling the post- and pre-contrast subtraction image from 0 to 1. BV is measured in one cystic mass (-6±7)% and one complex mass (17±8)% with sub-regions BV up to (32±10)% and (30±7)%. The quantification of BV provides a measurement of the distribution of micro-vessel density, reflecting the vascularity of the kidneys and masses. This technique potentially benefits surgical planning, renal mass characterization, and disease progression in patients with impaired renal function.