P3I-2 A High Resolution Digital Ultrasound System for Imaging of Zebrafish

The zebrafish (Danio rerio) has become a popular animal model for the study of vertebrate biology, due to its simple anatomy, rapid external development, and easiness to maintain in large numbers. However, traditional imaging modalities do not provide adequate spatial resolutions to describe its very small internal structures. In this research, an ultrasound bio-microscope (UBM) system (exceeding 80 MHz) was developed with resolutions around 20 micron for in vivo imaging of the zebrafish. This UBM system was implemented in a fully digital version with the capability of B-mode imaging as well as pulsed-wave spectral Doppler measurement. The system has -6dB resolutions of 19 and 28 microns axially and laterally, respectively, by phantom measurement. In vivo experiments on zebrafish displayed its detailed internal structures. Preliminary spectral Doppler measurement on flow phantom showed that this instrument permits flow measurement up to 40 cm/s, with velocity and temporal resolutions of 150 micron/s and 100 ms, respectively, in a sample volume with dimensions of 40 and 150 microns laterally and axially