Excitation spectroscopy in multispectral optical fluorescence tomography: methodology, feasibility and computer simulation studies

Molecular probes used for in vivo optical fluorescence tomography (OFT) studies in small animals are typically chosen such that their emission spectra lie in the 680–850 nm wavelength range. This is because tissue attenuation in this spectral band is relatively low, allowing optical photons even from deep sites in tissue to reach the animal surface and consequently be detected by a CCD camera. The wavelength dependence of tissue optical properties within the 680–850 nm band can be exploited for emitted light by measuring fluorescent data via multispectral approaches and incorporating the spectral dependence of these optical properties into the OFT inverse problem—that of reconstructing underlying 3D fluorescent probe distributions from optical data collected on the animal surface. However, in the aforementioned spectral band, due to only small variations in the tissue optical properties, multispectral emission data, though superior for image reconstruction compared to achromatic data, tend to be somewhat redundant. A different spectral approach for OFT is to capitalize on the larger variations in the optical properties of tissue for excitation photons than for the emission photons by using excitation at multiple wavelengths as a means of decoding source depth in tissue. The full potential of spectral approaches in OFT can be realized by a synergistic combination of these two approaches, that is, exciting the underlying fluorescent probe at multiple wavelengths and measuring emission data multispectrally. In this paper, we describe a method that incorporates both excitation and emission spectral information into the OFT inverse problem. We describe a linear algebraic formulation of the multiple wavelength illumination-multispectral detection forward model for OFT and compare it to models that use only excitation at multiple wavelengths or those that use only multispectral detection techniques. This study is carried out in a realistic inhomogeneous mouse atlas using singular value decomposition and analysis of reconstructed spatial resolution versus noise. For simplicity, quantitative results have been shown for one representative fluorescent probe (Alexa 700®) and effects due to tissue autofluorescence have not been taken into account. We also demonstrate the performance of our method for 3D reconstruction of tumors in a simulated mouse model of metastatic human hepatocellular carcinoma.

[1]  Eric L. Miller,et al.  Imaging the body with diffuse optical tomography , 2001, IEEE Signal Process. Mag..

[2]  R. Leahy,et al.  Digimouse: a 3D whole body mouse atlas from CT and cryosection data , 2007, Physics in medicine and biology.

[3]  R. Tsien,et al.  The Fluorescent Toolbox for Assessing Protein Location and Function , 2006, Science.

[4]  Anuradha Godavarty,et al.  Fluorescence-enhanced optical tomography of a large tissue phantom using point illumination geometries. , 2006, Journal of biomedical optics.

[5]  M J Eppstein,et al.  Fluorescence-enhanced optical imaging of large phantoms using single and simultaneous dual point illumination geometries. , 2004, Medical physics.

[6]  Anne Koenig,et al.  In vivo mice lung tumor follow-up with fluorescence diffuse optical tomography. , 2008, Journal of biomedical optics.

[7]  S. Cherry In vivo molecular and genomic imaging: new challenges for imaging physics. , 2004, Physics in medicine and biology.

[8]  Vasilis Ntziachristos,et al.  Fluorescence optical tomography with a priori information , 2007, SPIE BiOS.

[9]  C. Bouman,et al.  Fluorescence optical diffusion tomography. , 2003, Applied optics.

[10]  Shimon Weiss,et al.  Advances in fluorescence imaging with quantum dot bio-probes. , 2006, Biomaterials.

[11]  Vasilis Ntziachristos,et al.  Looking and listening to light: the evolution of whole-body photonic imaging , 2005, Nature Biotechnology.

[12]  S L Jacques,et al.  In vivo determination of optical properties of normal and tumor tissue with white light reflectance and an empirical light transport model during endoscopy. , 2005, Journal of biomedical optics.

[13]  Andrew K. Dunn,et al.  A Time Domain Fluorescence Tomography System for Small Animal Imaging , 2008, IEEE Transactions on Medical Imaging.

[14]  Vasilis Ntziachristos,et al.  Performance of the red-shifted fluorescent proteins in deep-tissue molecular imaging applications. , 2008, Journal of biomedical optics.

[15]  B. Pogue,et al.  Spectrally resolved bioluminescence optical tomography. , 2006, Optics letters.

[16]  Vasilis Ntziachristos,et al.  Volumetric tomography of fluorescent proteins through small animals in vivo. , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[17]  S. Gambhir,et al.  Molecular imaging in living subjects: seeing fundamental biological processes in a new light. , 2003, Genes & development.

[18]  Vasilis Ntziachristos,et al.  Would near-infrared fluorescence signals propagate through large human organs for clinical studies? , 2002, Optics letters.

[19]  L. O. Svaasand,et al.  Boundary conditions for the diffusion equation in radiative transfer. , 1994, Journal of the Optical Society of America. A, Optics, image science, and vision.

[20]  Zeng-chen Ma,et al.  Metastatic models of human liver cancer in nude mice orthotopically constructed by using histologically intact patient specimens , 2005, Journal of Cancer Research and Clinical Oncology.

[21]  Richard M. Leahy,et al.  A method for atlas-based volumetric registration with surface constraints for optical bioluminescence tomography in small animal imaging , 2007, SPIE Medical Imaging.

[22]  Wolfgang Bangerth,et al.  Non-contact fluorescence optical tomography with scanning patterned illumination. , 2006, Optics express.

[23]  J. Ripoll,et al.  Visualization of antitumor treatment by means of fluorescence molecular tomography with an annexin V-Cy5.5 conjugate. , 2004, Proceedings of the National Academy of Sciences of the United States of America.

[24]  R. Hoffman,et al.  Models of human metastatic colon cancer in nude mice orthotopically constructed by using histologically intact patient specimens. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[25]  Andreas H Hielscher,et al.  Optical tomographic imaging of small animals. , 2005, Current opinion in biotechnology.

[26]  Arridge,et al.  Optical tomography in the presence of void regions , 2000, Journal of the Optical Society of America. A, Optics, image science, and vision.

[27]  Vasilis Ntziachristos,et al.  Shedding light onto live molecular targets , 2003, Nature Medicine.

[28]  R. Leahy,et al.  Fast iterative image reconstruction methods for fully 3D multispectral bioluminescence tomography , 2008, Physics in medicine and biology.

[29]  B. Chance,et al.  Optical method. , 1991, Annual review of biophysics and biophysical chemistry.

[30]  Michael E Phelps,et al.  Technology Insight: novel imaging of molecular targets is an emerging area crucial to the development of targeted drugs , 2008, Nature Clinical Practice Oncology.

[31]  Vasilis Ntziachristos,et al.  Experimental fluorescence tomography of tissues with noncontact measurements , 2004, IEEE Transactions on Medical Imaging.

[32]  B. Rice,et al.  Three-dimensional reconstruction of in vivo bioluminescent sources based on multispectral imaging. , 2007, Journal of biomedical optics.

[33]  R. Weissleder,et al.  Experimental three-dimensional fluorescence reconstruction of diffuse media by use of a normalized Born approximation. , 2001, Optics letters.

[34]  Shi Ke,et al.  Comparison of visible and near-infrared wavelength-excitable fluorescent dyes for molecular imaging of cancer. , 2007, Journal of biomedical optics.

[35]  Vasilis Ntziachristos,et al.  The inverse source problem based on the radiative transfer equation in optical molecular imaging , 2005 .

[36]  K. Paulsen,et al.  Spatially varying optical property reconstruction using a finite element diffusion equation approximation. , 1995, Medical physics.

[37]  Jie Tian,et al.  MicroCT-guided Bioluminescence Tomography Based on the Adaptive Finite Element Tomographic Algorithm , 2006, 2006 International Conference of the IEEE Engineering in Medicine and Biology Society.

[38]  S. Arridge Optical tomography in medical imaging , 1999 .

[39]  Richard M Levenson,et al.  Autofluorescence removal, multiplexing, and automated analysis methods for in-vivo fluorescence imaging. , 2005, Journal of biomedical optics.

[40]  Kathryn E. Luker,et al.  Optical Imaging: Current Applications and Future Directions , 2007, Journal of Nuclear Medicine.

[41]  S. Arridge,et al.  Optical imaging in medicine: II. Modelling and reconstruction , 1997, Physics in medicine and biology.

[42]  Stefan Andersson-Engels,et al.  Fluorescence spectra provide information on the depth of fluorescent lesions in tissue. , 2005, Applied optics.

[43]  V. Chernomordik,et al.  Time Resolved Fluorescence Lifetime Imaging System For In Vivo Characterization of Tumors , 2007, LEOS 2007 - IEEE Lasers and Electro-Optics Society Annual Meeting Conference Proceedings.

[44]  Alexander D Klose,et al.  Fluorescence tomography with simulated data based on the equation of radiative transfer. , 2003, Optics letters.

[45]  M S Patterson,et al.  Imaging of fluorescent yield and lifetime from multiply scattered light reemitted from random media. , 1997, Applied optics.

[46]  Jacques Neefjes,et al.  Fluorescent probes for proteolysis: Tools for drug discovery , 2004, Nature Reviews Drug Discovery.

[47]  C A Thompson,et al.  Frequency domain modeling of reradiation in highly scattering media. , 1997, Applied optics.

[48]  Guillaume Bal,et al.  Transport- and diffusion-based optical tomography in small domains: a comparative study. , 2007, Applied optics.

[49]  E. Hoffman,et al.  In vivo mouse studies with bioluminescence tomography. , 2006, Optics express.

[50]  Wolfgang Bangerth,et al.  Fully adaptive FEM based fluorescence optical tomography from time-dependent measurements with area illumination and detection. , 2006, Medical physics.

[51]  M. Schweiger,et al.  A finite element approach for modeling photon transport in tissue. , 1993, Medical physics.

[52]  Jenghwa Chang,et al.  Imaging of fluorescence in highly scattering media , 1997, IEEE Transactions on Biomedical Engineering.

[53]  M. Defrise,et al.  Image reconstruction. , 2006, Physics in medicine and biology.

[54]  V. Chernomordik,et al.  Fluorescence Lifetime Imaging System for in Vivo Studies , 2007, Molecular imaging.

[55]  V. Ntziachristos Fluorescence molecular imaging. , 2006, Annual review of biomedical engineering.

[56]  B. Rice,et al.  In vivo imaging of light-emitting probes. , 2001, Journal of biomedical optics.

[57]  Brian W. Pogue,et al.  Mathematical model for time-resolved and frequency-domain fluorescence spectroscopy in biological tissues. , 1994, Applied optics.

[58]  Dario Fasino,et al.  An inverse Robin problem for Laplace's equation: theoretical results and numerical methods , 1999 .

[59]  Bin Chen,et al.  Fluorescence Imaging in Vivo: Raster Scanned Point-Source Imaging Provides More Accurate Quantification than Broad Beam Geometries , 2004, Technology in cancer research & treatment.

[60]  J. Culver,et al.  Time-dependent whole-body fluorescence tomography of probe bio-distributions in mice. , 2005, Optics express.

[61]  R. Anderson,et al.  The optics of human skin. , 1981, The Journal of investigative dermatology.

[62]  S. Nie,et al.  In vivo cancer targeting and imaging with semiconductor quantum dots , 2004, Nature Biotechnology.

[63]  Stefan Andersson-Engels,et al.  Spatially varying regularization based on spectrally resolved fluorescence emission in fluorescence molecular tomography. , 2007, Optics express.

[64]  John McGhee,et al.  Radiative transport-based frequency-domain fluorescence tomography , 2008, Physics in medicine and biology.

[65]  R. Weissleder,et al.  Charge-coupled-device based scanner for tomography of fluorescent near-infrared probes in turbid media. , 2002, Medical physics.

[66]  Paul E. Kinahan,et al.  PET Image Reconstruction , 2005 .

[67]  Ge Wang,et al.  Multispectral Bioluminescence Tomography: Methodology and Simulation , 2006, Int. J. Biomed. Imaging.

[68]  B. Wilson,et al.  The propagation of optical radiation in tissue I. Models of radiation transport and their application , 1991, Lasers in Medical Science.

[69]  Vasilis Ntziachristos,et al.  Accuracy of fluorescent tomography in the presence of heterogeneities:study of the normalized born ratio , 2005, IEEE Transactions on Medical Imaging.

[70]  J. P. Robinson,et al.  An excitation wavelength-scanning spectral imaging system for preclinical imaging. , 2008, The Review of scientific instruments.

[71]  Bernd J Pichler,et al.  A hyperspectral fluorescence system for 3D in vivo optical imaging , 2006, Physics in medicine and biology.

[72]  A. Joshi,et al.  Adaptive finite element based tomography for fluorescence optical imaging in tissue. , 2004, Optics express.

[73]  R. Weissleder,et al.  In vivo imaging of tumors with protease-activated near-infrared fluorescent probes , 1999, Nature Biotechnology.

[74]  Germund Dahlquist,et al.  Numerical methods in scientific computing , 2008 .

[75]  Vasilis Ntziachristos,et al.  Surface Reconstruction for Free-Space 360 $^{\circ}$ Fluorescence Molecular Tomography and the Effects of Animal Motion , 2008, IEEE Transactions on Medical Imaging.

[76]  R. Leahy,et al.  Hyperspectral and multispectral bioluminescence optical tomography for small animal imaging , 2005, Physics in medicine and biology.

[77]  A. Chatziioannou,et al.  Tomographic bioluminescence imaging by use of a combined optical-PET (OPET) system: a computer simulation feasibility study , 2005, Physics in medicine and biology.

[78]  J. Ripoll,et al.  Free-space propagation of diffuse light: theory and experiments. , 2003, Physical review letters.

[79]  Ge Wang,et al.  A finite-element-based reconstruction method for 3D fluorescence tomography. , 2005, Optics express.

[80]  Germund Dahlquist,et al.  Numerical Methods in Scientific Computing: Volume 1 , 2008 .

[81]  Vasilis Ntziachristos,et al.  IMAGING SCATTERING MEDIA FROM A DISTANCE: THEORY AND APPLICATIONS OF NONCONTACT OPTICAL TOMOGRAPHY , 2004 .

[82]  Anuradha Godavarty,et al.  Fluorescence-enhanced optical tomography using referenced measurements of heterogeneous media , 2003, IEEE Transactions on Medical Imaging.

[83]  Vasilis Ntziachristos,et al.  Noncontact optical imaging in mice with full angular coverage and automatic surface extraction. , 2007, Applied optics.

[84]  A. Welch,et al.  A review of the optical properties of biological tissues , 1990 .

[85]  A. Chaudhari Hyperspectral and multispectral optical bioluminescence and fluorescence tomography in small animal imaging , 2007 .

[86]  Robert M. Hoffman,et al.  Orthotopic Metastatic Mouse Models for Anticancer Drug Discovery and Evaluation: a Bridge to the Clinic , 2004, Investigational New Drugs.