CenSSIS: Acoustics Group at Boston University Tissue Harmonic Imaging (THI)

In conventional diagnostic ultrasound imaging images are formed from the scattering and reflection of a probing pulse from an object. In nonlinear or harmonic imaging the images are formed from the higher harmonics of the fundamental probing pulse. This project aims at trying to understand the underlying physics behind tissue harmonic imaging (THI). In this modality the nonlinear properties of tissue, which distort the probing pulse and produce higher harmonics, are used to produce the nonlinearity. THI forms images from the second harmonic signal that is generated by nonlinear distortion as the ultrasound pulse propagates into the body. THI yields images that are often clearer than images formed from the fundamental signal, even though the received energy in the second harmonic is 15dB below the energy in the fundamental. Although THI is available on some clinical scanners it was discovered through serendipity and the reasons for the improvement in image quality is not understood. We are undertaking a combination of experimental and computational approaches to understand the underlying physics. If the physics can be understood it will be possible to enhance the performance of THI over it current empirically determined state.

Investigators:
Robin O. Cleveland, Thomas L. Szabo, Yuan Jing, Dept. of Aero & Mech Eng, Boston University