24 February 2009 HYPR-spectral photoacoustic CT for preclinical imaging
Author Affiliations +
We have designed and built a prototype PCT (photoacoustic CT) scanner suitable for small animal imaging that acquires a sparse set of 128 photoacoustic, radial "projections" uniformly distributed over the surface of a hemisphere in response to optical absorption from a tunable, pulsed NIR (near-infrared) laser. Acquisition of a denser set of projections is achieved by rotating the hemispherical array about its vertical axis and acquiring additional, interleaved projections. Each detector in the array is a 3-mm diameter, piezo-composite with a center frequency of 5 MHz and 70% bandwidth. Spatial resolution is < 300 μm and nearly isotropic, owing to the array geometry. Preliminary results acquired at half of the allowable laser power and with no system optimizations show a low contrast sensitivity sufficient to detect a 350 nM concentration of a NIR-absorbing organic dye embedded in 12.5 mm of soft tissue. This scanner design will allow our group to take advantage of HYPR (HighlY constrained backPRojection) reconstruction techniques, which can significantly improve temporal (or spectral) resolution, without sacrificing signal-to-noise or spatial resolution. We will report how these accelerated reconstruction techniques can be implemented with this PCT scanner design. Using this approach, we may be able to achieve 100-ms temporal resolution for dynamic studies throughout a 20-mm-diameter imaging volume.
© (2009) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Robert Kruger, Robert Kruger, Daniel Reinecke, Daniel Reinecke, Gabe Kruger, Gabe Kruger, Michael Thornton, Michael Thornton, Paul Picot, Paul Picot, Timothy Morgan, Timothy Morgan, Keith Stantz, Keith Stantz, Charles Mistretta, Charles Mistretta, } "HYPR-spectral photoacoustic CT for preclinical imaging", Proc. SPIE 7177, Photons Plus Ultrasound: Imaging and Sensing 2009, 71770F (24 February 2009); doi: 10.1117/12.810175; https://doi.org/10.1117/12.810175

Back to Top