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Investigating the temporal evolution of the cerebral hemodynamic response using diffuse optical tomography /Siegel, Andrew M. January 2004 (has links)
Thesis (Ph.D.)--Tufts University, 2004. / Adviser: David A. Boas. Submitted to the Dept. of Electrical Engineering. Includes bibliographical references (leaves 407-416). Access restricted to members of the Tufts University community. Also available via the World Wide Web;
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Adaptive finite element methods for fluorescence enhanced optical tomographyJoshi, Amit 30 October 2006 (has links)
Fluorescence enhanced optical tomography is a promising molecular imaging
modality which employs a near infrared fluorescent molecule as an imaging agent
and time-dependent measurements of fluorescent light propagation and generation.
In this dissertation a novel fluorescence tomography algorithm is proposed to reconstruct
images of targets contrasted by fluorescence within the tissues from boundary
fluorescence emission measurements. An adaptive finite element based reconstruction
algorithm for high resolution, fluorescence tomography was developed and validated
with non-contact, planewave frequency-domain fluorescence measurements on
a tissue phantom. The image reconstruction problem was posed as an optimization
problem in which the fluorescence optical property map which minimized the
difference between the experimentally observed boundary fluorescence and that predicted
from the diffusion model was sought. A regularized Gauss-Newton algorithm
was derived and dual adaptive meshes were employed for solution of coupled photon
diffusion equations and for updating the fluorescence optical property map in
the tissue phantom. The algorithm was developed in a continuous function space
setting in a mesh independent manner. This allowed the meshes to adapt during
the tomography process to yield high resolution images of fluorescent targets and to accurately simulate the light propagation in tissue phantoms from area-illumination.
Frequency-domain fluorescence data collected at the illumination surface was used
for reconstructing the fluorescence yield distribution in a 512 cm3, tissue phantom
filled with 1% Liposyn solution. Fluorescent targets containing 1 micro-molar Indocyanine
Green solution in 1% Liposyn and were suspended at the depths of up to 2cm
from the illumination surface. Fluorescence measurements at the illumination surface
were acquired by a gain-modulated image intensified CCD camera system outfitted
with holographic band rejection and optical band pass filters. Excitation light at
the phantom surface source was quantified by utilizing cross polarizers. Rayleigh
resolution studies to determine the minimum detectable sepatation of two embedded
fluorescent targets was attempted and in the absence of measurement noise, resolution
down to the transport limit of 1mm was attained. The results of this work
demonstrate the feasibility of high-resolution, molecular tomography in clinic with
rapid non-contact area measurements.
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Ultrasound-modulated optical tomography in soft biological tissuesSakadzic, Sava 17 September 2007 (has links)
Optical imaging of soft biological tissues is highly desirable since it is nonionizing
and provides sensitive contrast information which enables detection of physiological
functions and abnormalities, including potentially early cancer detection. However,
due to the diffusion of light, it is dificult to achieve simultaneously both good spatial
resolution and good imaging depth with the pure optical imaging modalities.
This work focuses on the ultrasound-modulated optical tomography - a hybrid
technique which combines advantages of ultrasonic resolution and optical contrast.
In this technique, focused ultrasound and optical radiation of high temporal co-herence are simultaneously applied to soft biological tissue, and the intensity of the
ultrasound-modulated light is measured. This provides information about the optical
properties of the tissue, spatially localized at the interaction region of the ultrasonic
and electromagnetic waves.
In experimental part of this work we present a novel implementation of high-resolution ultrasound-modulated optical tomography that, based on optical contrast,
can image several millimeters deep into soft biological tissues. A long-cavity confocal
Fabry-Perot interferometer was used to detect the ultrasound-modulated coherent
light that traversed the scattering biological tissue. Using 15-MHz ultrasound, we
imaged with high contrast light absorbing structures placed 3 mm below the surface
of chicken breast tissue. The resolution along the axial and the lateral directions with respect to the ultrasound propagation direction was better than 70 and 120ùm, respectively. This technology is complementary to other imaging technologies,
such as confocal microscopy and optical-coherence tomography, and has potential for
broad biomedical applications.
In the theoretical part we present various methods to model interaction be-tween the ultrasonic and electromagnetic waves in optically scattering media. We first extend the existing theoretical model based on the diffusing-wave spectroscopy
approach to account for anisotropic optical scattering, Brownian motion, pulsed ul-trasound, and strong correlations between the ultrasound-induced optical phase in-crements. Based on the Bethe-Salpeter equation, we further develop a more general
correlation transfer equation, and subsequently a correlation diffusion equation, for
ultrasound-modulated multiply scattered light. We expect these equations to be
applicable to a wide spectrum of conditions in the ultrasound-modulated optical tomography of soft biological tissues.
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Magneto-motive detection of nanoparticles and hemoglobinOh, Jung Hwan 28 August 2008 (has links)
Not available / text
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Μελέτη και εφαρμογές της οπτικής τομογραφίαςΑναγνωστόπουλος, Δημήτριος 21 January 2009 (has links)
Η οπτική τομογραφία διάχυσης είναι μια πρόσφατη μέθοδος απεικόνισης που χρησιμοποιεί φωτόνια κοντά στο φάσμα των υπερύθρων για τον υπολογισμό ορισμένων ιδιοτήτων των ιστών και η οποία ανακατασκευάζει τρισδιάστατες εικόνες βάση αυτών.
Σε αυτή τη διπλωματική εργασία αναλύονται πρόσφατες μελέτες που έχουν πραγματοποιηθεί γύρω από τη νέα αυτή τεχνική, οι οποίες περιλαμβάνουν μια ιστορική αναδρομή στην εξέλιξή της, τις προσπάθειες μαθηματικής βελτίωσης των τεχνικών χαρακτηριστικών της, καθώς και πειραματικές εφαρμογές της στην παρακολούθηση εγκεφαλικών βλαβών σε νεογνό, στην ανταπόκριση μιας ασθενούς με καρκίνο του μαστού στη χημειοθεραπεία και στην πορεία ασθενών με ρευματοειδή αρθρίτιδα.
Τα πορίσματα αυτής της εργασίας οδηγούν στο συμπέρασμα ότι σε μετέπειτα χρόνια μετά από βελτιώσεις στην τεχνολογία και στην επεξεργασία των σημάτων, η DOT θα αποδειχθεί μια χρήσιμη μέθοδος διάγνωσης και παρακολούθησης πολλών ασθενειών. / Diffuse optical tomography (DOT) is a recent imaging method which uses near-infrared photon emission in order to measure certain tissue properties, and processes them to reconstruct 3-D images.
In this project, we analyze five studies on this method which include: a historic overview, the efforts of mathematical optimization of its technical features as well as some of the clinical trials using it, such as the observation of a neonate with brain lesions, the response of a breast-cancer patient to chemotherapy and the progress of patients suffering from rheumatoid arthritis.
Based on this project’s conclusions, after several years and several improvements in its features and data-processing, DOT will prove to be a useful diagnostic and observational method for many illnesses.
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Frequency resolved cell sizes using optical coherence tomographyGoya, Jaren M (Jaren Minoru) January 2006 (has links)
Thesis (M.S.)--University of Hawaii at Manoa, 2006. / Includes bibliographical references (leaves 50-51). / xi, 51 leaves, bound ill. 29 cm
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Development of high-resolution optical tomography with a larger-size projection acquisitionHuang, Hsuan-Ming January 2007 (has links)
Thesis (M.S.)--University of Missouri-Columbia, 2007. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on November 11, 2008) Includes bibliographical references.
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Statistical modeling and structured regularization for fluorescence molecular tomography a dissertation /Hyde, Damon Eliot. January 1900 (has links)
Thesis (Ph. D.)--Northeastern University, 2008. / Title from title page (viewed May 21, 2009). Graduate School of Engineering, Dept. of Electrical and Computer Engineering. Includes bibliographical references (p. [138] - 156).
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The characterization of retinal nerve fiber layer thickness in normal, high-tension and normal-tension glaucoma using optical coherence tomographyMok, Kwok-hei. January 2005 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2005. / Title proper from title frame. Also available in printed format.
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Magneto-motive detection of nanoparticles and hemoglobinOh, Jung Hwan, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
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