History of inflammatory myositis versus steroid myopathy, now off of steroids. CK elevated. Evaluate for inflammatory myositis. Right thigh: There is mild generalized fatty atrophy of the musculature of the right thigh with relative sparing of the vastus intermedius muscle. There is relatively severe fatty atrophy of the gluteus maximus muscle distally. On the fat-suppressed T2-weighted sequences, there is mild increased signal intensity of the gracilis muscle within the proximal and mid thigh as well as mild increased signal intensity within the proximal adductor magnus muscle. There is also mild enhancement of the proximal adductor magnus muscle following gadolinium administration. There is increased signal intensity within the obturator internus and externus muscles on the fat-suppressed T2-weighted images with mild enhancement of these muscles following gadolinium administration; little, if any, fatty infiltration of these muscles is noted on the T1-weighted images. There is mild increased signal intensity on fat-suppressed T2-weighted images within the lateral fibers of the gluteus maximus muscle with mild enhancement following gadolinium administration. There is mild peritrochanteric edema and enhancement which may reflect mild inflammation, of questionable clinical significance. The right hip appears normal. There is a small right knee joint effusion with synovial enhancement indicating mild synovitis. Signal intensity of the femur is normal.Left thigh.: There is mild generalized fatty atrophy of the musculature of the left thigh with relative sparing of the vastus intermedius. There is relatively severe fatty atrophy of the gluteus maximus muscle distally. On the fat-suppressed T2-weighted sequences there is increased signal intensity of the mid gracilis muscle with minimal if any enhancement following intravenous gadolinium administration. There is also patchy increased signal intensity within the proximal adductor magnus muscle which perhaps enhances slightly following gadolinium administration. There is increased signal intensity within the proximal sartorius muscle on fat-suppressed T2-weighted images, with mild enhancement following gadolinium administration. There is mild increased signal intensity within the proximal rectus femoris muscle along the myotendinous junction on T2-weighted images, with mild patchy enhancement noted following gadolinium administration. Similar abnormal signal intensity and enhancement is noted focally within the vastus lateralis muscle. As on the right side, there is increased signal intensity within the lateral fibers of the gluteus maximus muscle on the fat-suppressed T2-weighted images with mild enhancement following gadolinium administration. There is also increased signal intensity within the obturator internus and externus muscles on the fat-suppressed T2-weighted images, with mild enhancement following gadolinium administration; there is little if any fatty atrophy of these muscles on the T1-weighted images. There is mild peritrochanteric edema and enhancement which may reflect mild inflammation, of questionable clinical significance. The left hip joint appears normal. There is a small to moderate-sized left knee joint effusion with synovial enhancement indicating a mild synovitis. The signal intensity of the left femur is normal.
Relatively symmetric myositis pattern as described above, with mild diffuse fatty atrophy of the thigh musculature and relatively severe fatty atrophy of the distal gluteus maximus muscle bilaterally, along with scattered foci of mild muscle edema and enhancement as described above.