If we are talking about cancer, then you can focus on a few points, if you are talking about a follow-up study:
1. If there was no surgical intervention, then you can describe (calculate, determine on the images) how the shape and size of the cancerous formation has changed, comparing the results of the repeated MRI study with the results of the first study.
This will allow you, for example, to calculate the average growth rate of the cancerous formation, if you know the time between two MRI studies.
This is the first group of subjects, if you had such patients at all.
2. If the patient had chemotherapy, then evaluate the dynamics of the decrease in the shape and size of the cancerous formation, comparing the results of the repeated MRI study with the results of the first study.
You can then evaluate the effect of the treatment (how many stages (procedures) there were) on the cancerous formation (how much it decreased in size).
3. For the first and second cases, and also if there was surgical intervention, then you can indicate whether new cancerous formations have appeared (not only in the ovaries, but also in other tissues and organs) depending on the stage of cancer, as well as the size of the tumor.