On the left an example of adult onset muscular dystrophy.
There is subtle high signal intensity of the quadriceps muscle bilaterally due to edema, with a feathery appearance.
Most of the adductor muscle is normal.
Note the lack of skin edema.
This is an important finding to be able to differentiate from inflammatory myositis, in which the skin is also edematous.
The imaging findings correspond to the acute stage of muscular dystrophy.
In a chronic setting, the muscle will be atrophied with fatty replacement.