Model based reduction of ultrasound reverberation artifacts

• Main Author: Wang, Jing.
• Other Authors: Zhang Cishen
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Control and instrumentation::Medical electronics
• Online Access: http://hdl.handle.net/10356/15803
• Institution: Nanyang Technological University

This study is to address the low image quality problem of medical ultrasound imaging in terms of reverberation artifacts, and subsequently to propose a model as a basis for the reduction of such artifacts. Reverberation caused by reflections of ultrasound signal between two interfaces gives rise to multiple copies of the anatomy at the interface, significantly degrading image quality and accuracy. This study is an extension of the method for the identification of reverberation echoes in multilayered media, based on the comparison of their power spectra (estimated via Fast Fourier Transform) through a least mean square approach, and linear combination of the temporal relationship (based on time-of-flight). To provide a systematic approach, the author investigated the nature of reverberation artifacts formation, and proposed a mathematical model to express reverberations phenomenon concisely and accurately. In addition, the algorithm of this method was developed including time-of-flight acquisition and Linear Combination formation. Last but not least, this analysis was extended to 2D data to generate reverberation-free images which will be more beneficial for clinical diagnosis. Through the qualitative and quantitative assessments of the performance, the objectives of reverberation reduction and improvement of ultrasound imaging quality to obtain accurate diagnosis information were successfully achieved.