This MRI scan provides an indication of how sex steroids can affect patients. Studies are currently underway to assess the effect of androgens on the muscle strength and body fat of men.
The "before" MRI of the leg of a male, prior to taking testosterone, shows high density matter which is fat. The "after" MRI, taken after the male took testosterone, shows substantially less fat in that muscle. This illustrates some of the exciting things that can be done using sex steroids.