Patent ID: 7774041

Claim:
An index calculation method comprising: preparing first time-density curves concerning arteries in a specific region, second time-density curves concerning tissues in the specific region, and third time-density curves concerning veins in the specific region from a plurality of continuous images concerning the specific region of a subject with a contrast medium injected therein; correcting the time-density curves concerning the arteries by applying a respective corrective factor so that an area under each of the of corrected time-density curves concerning the arteries is equivalent to an area under a corresponding time density curve concerning veins; calculating modulation transfer functions indicating local blood flow circulations in the tissues with respect to the arteries by curve-fitting so that residual errors of the second time-density curves with respect to convolution of the modulation transfer functions and first time-density curves are minimized; calculating indices concerning the local blood flow circulations with respect to the respective arteries from the modulation transfer functions; preparing maps of the indices for the arteries; and combining the maps of the indices into one map in accordance with the residual errors.