Description of tissue condition by ischaemia with the assistance of acoustic parameters

During ischaemia the tissue of organs undergoes progressive changes in the physiological state of the cells. After a critical time the tissue is in a condition where resuscitation is no longer possible. Monitoring of the condition of the tissue and the cells is of great practical interest for evaluating the probability of successful revival of the organ. The damage of cells and tissue structure changes the elasto-acoustic properties of the tissue. These modifications generated by ischaemic stress can be detected by ultrasound spectroscopy measurements. The ischaemic tolerance of canine liver, which has been perfused with protective solution, was investigated. The tissue condition in dependence on ischaemic time may be described by means of acoustic parameters, such as the relative backscattering coefficient and the frequency dependent attenuation. A dependence of these parameters upon the ischaemic time was found. The ultrasound spectroscopy method provides the possibility to describe the condition of organ tissue and the ischaemic tolerance, for example at transplantations. The application is simple and without any hazard to the tissue