1. A medical image processing apparatus comprising: a storage unit configured to store data of a series of medical images associated with an object; a time density curve generation unit configured to generate a plurality of time density curves respectively corresponding to a plurality of pixels from the series of medical images; an approximation processing unit configured to approximate a convolution between a specific time density curve of the time density curves and each of response functions respectively having shapes suited to types of kinetic models to each of the time density curves upon adjustment of at least one parameter which each of the kinetic models has; and a suitability index map generation unit configured to generate a plurality of types of suitability index maps respectively corresponding to the plurality of types of kinetic models based on a plurality of approximation errors respectively corresponding to the plurality of pixels, which are obtained by the approximation processing unit.