1. A method for performing magnetic resonance imaging (MRI) on a subject, comprising performing one or more of the following scans using an MRI machine: (a) a scout scan to determine the position of the subject's heart; (b) a stress perfusion MRI scan on the subject's heart; (c) a cine MRI scan on the subject's heart; (d) a rest perfusion MRI scan on the subject's heart; (e) a coronary MRA scan on the subject's heart; and (f) a delayed enhancement MRI scan on the subject's heart; wherein (a) one or more scan is performed by using a continuous three dimensional radial acquisition scheme that results in the acquisition of a free-breathing k-space dataset, and (b) image reconstruction for one or more scan is performed using a constrained or compressed sensing scheme, and wherein the method does not require (1) ECG triggering, (2) breath-holding by the subject, or (3) the use of a diaphragm navigator.