1. A method for magnetic resonance and ultrasound parametric image fusion, the method comprising: acquiring ultrasound parametric data representing a region of a patient at a first rate, the ultrasound parameter data comprising first values of a parameter, the first values derived from detected ultrasound data; acquiring magnetic resonance parametric data representing the region of the patient at a second rate less than the first rate, the magnetic resonance parameter data comprising second values of the parameter, the second values derived from magnetic resonance data; calculating fused values from the first and second values, the fused values representing the region of the patient at a third rate greater than the second rate; and generating fused, parametric images from the fused values.