An improved noise robust localized motion imaging for monitoring HIFU treatment

Abstract

High intensity focused ultrasound (HIFU) is a minimally invasive treatment modality for cancerous tumors. The monitoring of HIFU treatment is extremely important. Localized motion imaging (LMI) is a HIFU monitoring method basing on Harmonic motion method (HMI). It estimates the coagulation length by detecting the change of tissue stiffness. However, the previous LMI is not robust to noise, thus two techniques are employed to improve its noise robustness in this study. First, dynamic cross correlation window (DCCW) is used to obtain vibration amplitude with noise suppression. Second, vibrationfrequency band pass filter (VBPF) is employed to calculate the amount of vibration with expected frequency. The qualitative evaluation indicates that the two techniques are able to suppress the affection of noise on the vibration amplitude and vibration amount, respectively. Furthermore, the quantitative comparison demonstrates that the improved LMI is able to give higher accuracy of coagulation length estimation than the previous LMI, and it reduces the root mean square error (RMSE) from 2.52 to 1.84 mm. In this article, an improved noise robust LMI is proposed for monitoring HIFU treatment.

Effect of dissolved oxygen level of water on ultrasonic power measured using calorimetry

“…Recently, concern has been growing regarding the safety of ultrasonic therapeutic equipment such as high-intensity focused ultrasound (HIFU) [1][2][3][4][5][6][7] devices, which expose the human body to high-power ultrasound. The HIFU devices used in clinical practice destroy cancer cells via the thermal effect of high-power ultrasound.…”

Improved highly accurate localized motion imaging for monitoring high-intensity focused ultrasound therapy

“…Many methods were proposed for measuring the stiffness or detecting the change in stiffness. [24][25][26][27][28][29][30][31][32][33][34][35][36][37] Ophir et al proposed elastography. 24) In their method, a stiffness map is estimated from the deformation of tissue due to pressure from the surface of the body.…”

“…Our group has developed a localized motion imaging (LMI) method, [34][35][36] which is a HMI-based method. It optimized the AM frequency of HIFU, which improves the detection sensitivity for small coagulation areas.…”