1. A medical imaging apparatus enabling imaging of an arbitrary slice in a three-dimensional space, which comprises: at least one hardware processor and memory configured to effect: an image acquirer configured to acquire a first image group consisting of one or more two-dimensional images parallel to a first slice plane, which is one of mutually crossing two slice planes, and a second image group consisting of one or more two-dimensional images parallel to a second slice plane, which is the other of the mutually crossing two slice planes, an anatomical feature extractor configured to extract information on an anatomical feature defined beforehand from a two-dimensional image, a recommended slice position calculator configured to calculate a recommended slice position to be recommended as a slice position, and a recommended slice position calculation storer configured to store recommended slice position calculation information necessary for calculating the recommended slice position according to an imaging region, wherein: the anatomical feature extractor is configured to extract information on a first anatomical feature from the first image group, and extract information on a second anatomical feature from the second image group, and the recommended slice position calculator is configured to calculate the recommended slice position by using the information on the first anatomical feature and the information on the second anatomical feature according to the recommended slice position calculation information.