Evaluation of accuracy of a theoretical model for predicting thenecrosed tissue volume during focused ultrasound surgery

摘要

The concept of thermal dose as a predictor for the size of thennecrosed tissue volume during high-intensity focussed ultrasound surgerynwas tested. The sensitivity of the predicted lesion size to thenuncertainties in the iso-dose constant, attenuation coefficient, andnthermal dose threshold of necrosis was studied. The predicted lesionnsize appears to be independent of attenuation at some high attenuationnvalues and certain depth in tissue. Thus, for a given target depth, anproper selection of frequency could minimize the lesion size variabilityndue to uncertainty in the tissue attenuation. The predicted lesion sizenwas less dependent on the uncertainties in the iso-dose constant andnthermal dose of necrosis. The predictions of the model were comparednwith experimental data in rabbit muscle, and experimental data in catnand rat brain measured by others. The agreement was found to be good innmost of the experiments. Similarly, the model was found to predict wellnthe trends of increasing power and pulse duration