Ankle scan, how does it tell if something is wrong?

Ankle Imaging: If your ankle hurts, and not responsive to treatment, mri, ct, or bone scans are common ways to look at the tissues involved. Many subtle injuries can be picked up by these scans that do not show on x-ray. How do they work? Mris are particularly helpful to see the fluid accummulation in a healing body response, bone scans show where bone activity is occuring and ct the 3d visualization of bone.