Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 15, 2018 | public
Book Section - Chapter

Imaging dichroism by photoacoustic computed tomography


Conventional photoacoustic computed tomography (PACT) images the spatial distribution of optical absorption, which is approximated as an isotropic optical property. The optical absorption of many biological tissues, however, is anisotropic. This anisotropy, known as dichroism or diattenuation, encodes rich information about molecular conformation and structural alignment. Here we report a novel imaging method called dichroism-sensitive PACT (DS-PACT). Using a lock-detection strategy, our method can measure the amplitude of tissue's dichroism and the orientation of the optic axis of uniaxial dichroic tissue, even at a depth of 3.25 transport mean free paths. We experimentally demonstrated DS-PACT by imaging plastic polarizers and ex vivo bovine tendons deep inside scattering media. Our method extends the functionality of PACT to include a new capability, imaging tissue absorption anisotropy.

Additional Information

© 2018 Society of Photo-Optical Instrumentation Engineers.

Additional details

August 19, 2023
January 14, 2024