Ultrasound-estimated percent intramuscular fat of muscles in the lower extremity was inversely associated with physical activity level and positively associated with body mass index in a recent study.
Ultrasound is advantageous because it is less costly and more accessible when compared with other imaging technologies.
The Muscle & Nerve study included 42 participants (16 men, 26 women) between the ages of 19 and 68 years, with a wide range of body mass index and physical activity levels.
"Ultrasound may be especially useful for examining muscle fat in certain individuals. For example, other imaging techniques such as DXA, MRI, and CT do not work well on people who have metal implants, have muscle spasticity, are morbidly obese, or are pregnant," said Dr. Hui-Ju Young, first author of the study. "As research has supported the association between the amount of intramuscular fat and other health conditions, people with disabilities who have those conditions need a test that allows them to better understand their muscle composition."
Study: Comparisons of Ultrasound-estimated Intramuscular Fat with Fitness and Health Indicators, Hui-Ju Young, Michael Southern, Kevin K. McCully, Muscle & Nerve, doi: 10.1002/mus.25105, published online 11 March 2016.