1. A method for non-contrast enhanced magnetic resonance angiography (MRA) of a three-dimensional (3D) volume of a subject having a vascular structure extending through the 3D volume and having flowing spins passing through vascular structure, the method comprising the steps of: a) applying, with a magnetic resonance imaging (MRI) system, at least one radiofrequency (RF) pulse to a first slice to label the flowing spins passing into a second slice located within the 3D volume adjacent to the first slice; b) acquiring, with the MRI system, imaging data from the second slice using a two-dimensional (2D) pulse sequence and sampling k-space using a non-Cartesian sampling pattern; c) repeating steps a) and b) to acquire a series of second slices located across the 3D volume to acquire respective sets of imaging data spanning the 3D volume; and d) reconstructing the sets of imaging data into a time-series of image frames depicting the flowing spins passing through the vascular structure.