Linked Life Data

10938778

Source:http://linkedlifedata.com/resource/pubmed/id/10938778

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2000-9-5
pubmed:abstractText
We employ photon migration to image absorbing objects embedded in a turbid medium. For improved resolution, we use early arriving photons (a few hundred picoseconds in excess of the time of flight), a regime in which the diffusion approximation breaks down. Our image reconstruction method is based on extension of x-ray computed tomography (CT) to the optical regime. The CT algorithm must be generalized to take into account the distributions of photon paths. We express the point spread function (PSF) in terms of the Green's function for the transport equation. This PSF then provides weighting functions for use in a generalized series expansion method of x-ray CT. Experiments were performed on a turbid medium with scattering and absorption properties similar to those of human breast tissue. Multiple absorbers were embedded into the medium to mimic tumors. Coaxial transmission scans were collected in two projections, and the early-time portions were analyzed. Through accurate modeling, we could remove the blurring associated with multiple scattering and obtain high-resolution images. Our results show that the diffusion approximation PSF is inadequate to describe the early arriving photons. A PSF incorporating causality is required to reconstruct accurate images of turbid media.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1083-3668
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
144-54
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Optical computed tomography in a turbid medium using early arriving photons.
pubmed:affiliation
Laser Biomedical Research Center, G. R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge 02139, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't