Removal of air from liver specimens via vacuum

Fresh liver specimens have been ultrasonically imaged in vitro in order to evaluate specimen air content before the acquisition of ultrasonic waveform data for tissue characterization studies. It was found necessary to expose liver slices to vacuum for about 16 h in order to remove enough air to acquire waveform data from air-free regions of interest in these slices. Larger portions of liver, and whole liver, were found to retain large amounts of air even after 16 h of exposure to vacuum.