Age-related changes of water and fat content in muscles estimated by magnetic resonance (MR) imaging.

The pixel values in fat/water suppression magnetic resonance (MR) images were measured for the thigh muscles of 18 healthy volunteers to investigate age-related changes in muscle water and fat content. Prior to the human studies the reproducibility of the data was confirmed using phantoms. The standard deviations (SDs) of the pixel values for one of the phantoms examined five times were found to be within a relatively narrow range. Both the pixel values in the fat suppression images (PV1) and the pixel values in the water suppression images (PV2) of all muscles tended to be higher in the oldest group. The results indicate that the water and fat content of skeletal muscles is higher in aged persons. Moreover, the PV1 in the non-dominant limbs was found to be increased in the extensor muscles of the knee joints, while the PV2 in the non-dominant limbs did not show a significant difference, except for the rectus femoris.