Ultrasound velocity and attenuation of porcine soft tissues with respect to structure and composition: I. Muscle

Ultrasound velocity and attenuation of soft tissues have been widely investigated. However, few studies completely covered considerable variations of both, structure and composition. The aim of this study was to collect acoustic reference data of porcine Longissimus muscle and associate them with compositional traits. In addition, measurements were conducted on fresh, formalin fixed, and frozen-thawed samples to evaluate the effect of processing on ultrasound parameters and comparisons with earlier investigations. Measurement conditions (temperature and fibre orientation) were realised close to hanging carcasses conditions. Sound velocity ranged from 1617 ± 6 to 1622 ± 5 ms−1, while attenuation mostly ranged from 1.0 ± 0.3 to 1.2 ± 0.3 dB MHz−1 cm−1. Only formalin fixed samples showed significantly higher attenuation (2.2 ± 0.6 dB MHz−1 cm−1). Highest correlations have been observed between intramuscular fat and attenuation (up to r = .7). The obtained results are anticipated to improve ultrasound based estimation of the intramuscular fat of pig muscle on intact carcasses.