Direct ultrasonic velocity measurements of mammalian collagen threads a )

Direct ultrasonic velocity measurements have been made in fresh eollagen threads from mammalian tendon at a frequency of 100 MHz using the scanning laser acoustic microscope. Tendon is of interest since it contains an unusually large amount of collagen, a structural protein thought to be important to the echographic visualizability of normal and pathologic tissues in medical ultrasound. Results indicate that ultrasonic velocity is appreciably higher than in soft tissues, lending support to the view that tendon, as well as collagen, is markedly distinguished ultrasonically from other biological tissues.