Prediction and Measurement of the Size of Thermal Lesion Induced by High Intensity Focused Ultrasound in a Tissue-Mimicking Phantom

초록

Based on a linear acoustic theory, the size of the thermal lesion induced by high intensity ultrasound (HIFU) in a tissue-mimicking phantom was predicted. The strong focal field of HIFU was predicted and the resulting temperature field in the phantom was calculated. The thermal dose distribution was estimated and the size of thermal lesion was determined and based on the evaluation of 240 min (at 43 degrees C) thermal dose boundary around the focus. The prediction of the lesion size with different peak positive focal pressures of HIFU was compared with the experimental measurement on thermal lesions visualized in an optically transparent polycrylamide hydrogel tissue-mimicking phantom exposed to HIFU, using a concave focused transducer with an aperture radius of 35.0 mm a focal length of 62.6 mm, and a center frequency of 1.1 MHz. It was shown that the prediction characteristically agreed with the measurement as the focal pressure varies. (C) 2009 The Japan Society of Applied Physics

키워드