A validation technique for quality assurance of quantitative MRI methods by comparing the measured magnetic properties of a phantom having a range of T1 and T2 values measured by an accelerated, clinically-practicable protocol with predicted values for that magnetic property calculated from a set of reference T1 and T2 values measured on the phantom. The prediction is based on a relationship between the values from the accelerated protocol and values from the reference measurements obtained by repeatedly scanning one or more phantoms.