Enhancement of Acoustic Properties of Ultrasound Matching Material between Probe and Soft Tissue

Abstract

Materials with acoustic parameters like soft tissue are essential, such as Tissue-Mimicking Materials for diagnostic ultrasound. Acoustic parameters consist of the sound velocity, acoustic impedance, and attenuation coefficient. In this study, the acoustic impedance of linseed gel is improved to be more suitable than traditional gel. The acoustic impedance of traditional gel is about 1.48 MRayl, although the average acoustic impedance of soft tissue is 1.633 MRayl. This difference in impedance between gel and soft tissue increases the amount of reflection at the interference between the probe and the skin of patient. Thus, the transmission of ultrasound into the patient decreased, which negatively affected the quality of the resultant image. This paper presents a new material whose acoustic impedance is close to 1.633 MRayl based on a Non-Destructive Testing system. The sound velocity and density of linseed gel were estimated using the pulse-echo technique at 20˚C in National Institutes of Standards, Cairo, Egypt. The acoustic quantities of linseed gel were calculated in laboratory at frequencies 4 MHz. The acoustic impedance is improved from 1.39 MRayl to 1.598 MRayl, which is more suitable than traditional gel and it could resemble soft tissue for ultrasound. Improving Ultrasound image can be achieved by using the proposed enhancement material.