Muscle-specific fat fractions during childhood development in typically developing children and children with cerebral palsy

Motivation: Little is known about the fat content of the skeletal muscles of typically developing children or children with cerebral palsy. Goal(s): To describe and compare muscle-specific intramuscular fat fractions in typically developing children and children with cerebral palsy. Approach: Proton density fat fractions were calculated for 11 lower leg muscles using mDixon MRI scans of 280 children (5 to 15 years), including 79 with cerebral palsy. Results: Age and sex did not affect mean fat fractions in typically developing children. Fat fractions varied across muscles. Fat fractions were larger, more variable, and increased with age in children with cerebral palsy. Impact: The comprehensive dataset and automation measurement techniques for measurement of muscle-specific fat fractions in typically developing children and children with cerebral palsy may be used to monitor muscle-specific disease progression or measure the effect of interventions.