Using RF ultrasound to monitor the progression of muscular dystrophy through passive stretching

A study has been made of the application of RF ultrasound to the detection of muscular dystrophy by monitoring passively stretched skeletal muscle. Normal and dystrophic male chickens were raised to the age of ten months. The animals were decapitated and the pectoral muscles were dissected and cut into strips approximately 3 cm in length. The muscle samples were stretched in 2 mm increments up to 8 mm. Ultrasound measurements were made at each stretch increment using an Aloka 280SL scanner which has been modified to allow digitization of the RF signal. The baseline values of integrated backscatter found were -25.2±2.4 dB for normal muscle and -20.3±1.6 dB for dystrophic muscle. A linear fit of integrated backscatter versus strain yielded a mean slope difference of 8.5±0.7 dB/cm/cm for normal tissue versus -1.3±0.3 dB/cm/cm for dystrophic issue