A computer-implemented method to generate a three-dimensional model, wherein the computer comprises one or more processors and memory accessible by the one or more processors, and the memory stores instructions that when executed by the one or more processors cause the computer to perform the computer-implemented method, includes: receiving first image data of a first portion of the patient's body in a first image modality, receiving second image data of a second portion of the patient's body in a second image modality, modifying the second image data from the second image modality to the first image modality, and generating, based on the first image data in the first image modality and the modified second image data in the second image modality, a three-dimensional model of the first portion and the second portion of the patient's body.