Elastography of beef muscle

Elastography, a technique that uses ultrasonic pulses to track the internal displacements of small tissue elements in response to an externally applied stress, has been applied to beef muscle. Beef longissimus (1 day post mortem) and semimembranosus (5 days post mortem) muscles were obtained from A maturity beef carcasses. Samples were vacuum-packaged and frozen to -20°C. For elastography measurements, muscles were equilibrated to a constant temperature (30° C± 0·5) in a water tank. Custom transmitters and receivers were used in conjunction with a 2·25 MHz medical transducer. The transducer was driven by a 286 PC, and the radio-frequency echoes digitized at 50 MHz and 8 bits. The pre- and post- compression echo trains (A-lines) were subjected to cross-correlation analysis. Visual interpretation of beef elastograms demonstrate circular areas of relatively inelastic tissues and smaller, banding areas of elastic tissues in the cross-section of beef longissimus muscle. The dark inelastic areas from the elastograms may be related to myofibrilar areas from the same muscle sections; the light, elastic band areas from the elastograms may be related to perimysiaal connective tissue or intramuscular fat. Fatty septa and a calcified abscess could be easily identified on the elastogram. These preliminary results demonstrate that elastography may have potential as a non-intrusive method of visualizing tissue components of beef muscle.