The observation of the evolution of a course of treatment can provide a powerful tool in understanding its efficacy. To visualize this, we produce animations allowing the visualization, as a function of time, of lesions in an organ. Such animations can be used in teaching or for patient education, influencing a patient's decision of following a course of treatment. The animation produced is a metamorphosis, or morph, describing how a source shape (pre‐treatment) gradually deforms into a target shape (post‐treatment). We implemented our method using the programming capabilities of current graphics cards (also known as graphics processing units or GPUs), so both visualization of the volumes and morph generation are performed in real‐time. We demonstrate our method on data from a patient's liver with lymphoma that was treated with chemotherapy and is currently on remission.