How to detect a specific region of image based on MRI?

Hi.

I'm doing research to implement automatic segmentation based on MRI (Magnetic Resonance Image) modals. For my case, prostate region is my focus . To make this happen, I'm thinking about these steps: 1. Image Acquisitions (about 20+ patients MRI - DICOM, each patient has around 15-30 slice images, and all these images will be dataset for training, you can see example of the dataset below)

2. From these dataset, I'm thinking to do manual segmentation with purpose to get the region of prostate (and the size of prostate in each slice is not consistent), so I can get the feature of prostate for any size, as you can see below. The green one is central of prostate, and the red one is peripheral zone of prostate.

3. So now, I have feature dataset of all slices, and I'm ready for train it to create classifier model.

4. ?

As I'm still green of MATLAB (sorry for this), I have no idea to train the dataset to create classifier that can detect the region of prostate (in any size), and automatically give a boundary to it. Should I use classifier + segmentation algorithm (level set/active contour) to get this done or only using classifier algorithm can get this done?

I' learning about object detection algorithm such as; Haar-Like Feature, but can get all of this clear (yes, I'm screwed). I would be very grateful if anyone can help me to give a clear idea, and guide me to make this happen, please.

Very Thank you

Regards

Septiawan