Quantification of soft tissue of the buttocks in a seated position

MRI is well suited to quantify soft tissue but challenges remain in using MRI to address soft tissue in a seated position and for studying how tissue responds to loading. IDEAL and T1 weighted images were used to quantify apparent fat fraction and soft tissue thicknesses of the buttocks in a side lying position with the tissue unloaded and loaded. Tissue compression during loading predominantly reflected changes in the muscle and tendon. Intramuscular fat was not related to the change in muscle/tendon. These methods may be useful to study soft tissue in populations at risk for pressure ulcer development.