Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Transmission and fluorescence angular domain optical projection tomography of turbid media

Not Accessible

Your library or personal account may give you access

Abstract

When imaging through turbid media, objects are often blurred by scattered light. An optical collimator (i.e., an angular filter array) improves images by accepting only photons propagating within a narrow solid angle about the direction of the incident light. These photons are expected to participate in a limited number of small-angle scattering events, maintaining their original propagation direction and, finally, contributing to the development of a faithful image of an object within a turbid medium. The collimation method, also referred to as angular domain imaging (ADI), applies to a see-through configuration where the incident collimated light beam can be aligned with the collimator in a transillumination mode of operation. In this paper, we present angular domain optical projection tomography (ADOPT), a method that can extract depth information of optical contrast in turbid media with high longitudinal resolution based on ADI technology. The resolution of the ADI system has been tested over various depths in a 5cm optical cuvette using a resolution target suspended in a homogeneous turbid medium. The ADOPT system reconstructed images from a series of angular domain projections collected at angular intervals. The system was used to measure the attenuation of an absorbing target in transmission mode (t-ADOPT) and to measure the light emitting from a fluorescent target (f-ADOPT). Tissue-mimicking phantoms were used to validate the performance of the method. In the t-ADOPT configuration, a background scattered light estimation and subtraction methodology was introduced to improve the imaging contrast. A target consisting of two graphite rods (0.9mm diameter) was suspended in the cuvette by a rotation stage. An Indocyanine Green-filled glass rod was used as an imaging target in the f-ADOPT arrangement. The target was placed in a manner such that the line of laser light was perpendicular to the longitudinal axis of the rods. Several projections were collected at increments of 1.8° and compiled into a sinogram. A transverse image was reconstructed from the sinogram by using filtered backprojection and image contrast was improved by experimental scatter measurements using a wedge prism and an image processing algorithm. The submillimeter target embedded in a 2cm thick scattering medium (reduced scattering coefficient 2.4cm1) was discernable in both the sinograms and the reconstructed images. In the f-ADOPT system, fluorescent line targets <1cm in diameter embedded in a 2cm thick scattering medium (reduced scattering coefficient 0.8cm1) were discernable in both the sinograms and the reconstructed images. The proposed method could be used as the basis to construct an optical tomographic scanner for simultaneous absorption and fluorescence-based imaging of biological specimens (i.e., up to 7mm across).

© 2009 Optical Society of America

Full Article  |  PDF Article
More Like This
Image contrast enhancement in angular domain optical imaging of turbid media

Fartash Vasefi, Bozena Kaminska, Glenn H. Chapman, and Jeffery J. L. Carson
Opt. Express 16(26) 21492-21504 (2008)

Contrast and resolution analysis of iterative angular domain optical projection tomography

Eldon Ng, Fartash Vasefi, Bozena Kaminska, Glenn H. Chapman, and Jeffrey J.L. Carson
Opt. Express 18(19) 19444-19455 (2010)

Characterization of an angular domain fluorescence optical projection tomography system for mesoscopic lymph node imaging

Veronica C. Torres, Chengyue Li, Wei Zhou, Jovan G. Brankov, and Kenneth M. Tichauer
Appl. Opt. 60(1) 135-146 (2021)

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Figures (7)

You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Equations (1)

You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Login to access Optica Member Subscription

Select as filters


Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All Rights Reserved