Characterization of Normal and Freeze-Thawed Tissues in vitro Through The Ultrasonic Integrated Backscatter.

BACKGROUND: The ultrasound guidance of cryotherapy could be improved if changes of tissue characterization parameters during freezing could be used to monitor freezing patterns and estimate the postoperative effects after surgery.

OBJECTIVE: The ultrasonic integrated backscatter analysis holds promise as an effective method for signal analysis and characterization of thawed tissues.

MATERIALS AND METHODS: The ultrasonic integrated backscatter has been found to be an important parameter for describing the ultrasonic scattering and characterization of biological tissues. However, its potential values in the evaluation of cryosurgical effects of tissues reserved unclear so far. Here, we investigated the power spectrum of acoustic signal to estimate the ultrasound integrated backscatter in normal and freeze-thawed tissues on porcine livers in vitro.

RESULTS: The experimental results carried out at 10 MHz using weakly focused pulse-echo signal element transducer indicated that the ultrasonic integrated backscatter in normal liver tissues is 31.3±4.6 whereas it is 44.2±6.5 in several pre-frozen and then thawed tissues.

CONCLUSION: These results disclosed the good correlation between the ultrasonic integrated backscatter and microstructures of the normal or thawed tissues, and hence demonstrated that the power spectrum holds promise to be used as an effective method for the characterization of thawed tissues ultrasonic integrated backscatter, which might offer a potential pragmatic prospect for the practice of monitoring transition zone between frozen and unfrozen tissues during the surgical therapy, and evaluating postoperative effects.