Temperature rise generated by ultrasound in the presence of contrast agent

Temperature elevation vs. time generated by a focused Gausssian ultrasound beam in the presence of contrast agents has been calculated using a perfect absorbing disc model. The results suggest that, if the contrast agent (Albunex) is introduced into the body intravenously, the temperature rise in the heart, which is 4.5 cm from the transducer, generated by 110-mW (the corresponding acoustic intensity at the transducer front surface is 0.4 W/cm2) 2-MHz ultrasound is about 2 degrees C in 10 s. The relationship between temperature rise and the blood perfusion, acoustic power and focal length is discussed.