Monitoring dynamic characteristics of treated region during high intensity focused ultrasound (HIFU) treatment

In this paper, two differential imaging methods using differential integrated backscatter (DIBS) and sum absolute differences (SAD) techniques to monitor the dynamic integral changes of treated region before, during and after high intensity focused ultrasound (HIFU) treatment based on a quasi real-time data acquisition system were investigated. Simultaneously, the dynamic local changes of mean IBS value and attenuation coefficient in treated region during HIFU treatment were also studied with different exposure parameters. Two-dimension RF data frames were acquired between HIFU exposures with the HIFU completely off during the acquisition to avoid interference from the HIFU beam. The results indicated that DIBS images obtained from RF data frames acquired before and after HIFU treatment can provide quantitative integral information about changes of the treated area and SAD images obtained from the two temporally adjacent RF data frames have very important relationship to cavitation during HIFU treatments.