[Localization of the freezing front in tissue by the ultrasound-A picture technic in cryotherapy]

The knowledge of the depth of infiltration of the freezing front in the treated tissue represented an essential demand for an optimal cryotherapy (sprayfreezing and contactfreezing). The hitherto used invasive measuring methods are connected with a tissue traumatisation and therefore only applicable in a limited way. On that account the non-invasive ultrasound-A-picture-technique was applied for defining the freezing front extension. Its qualification was represented in vitro (gelatin), in living biological tissue (muscle of rabbit), and on the human eye (cryotherapy of the primary glaucoma). The use of the sonography in the cryotherapy can be recommended for other special medical branches too.