title: Congruent MRI and near-infrared spectroscopy for functional and structural imaging of tumors.
abstract: We present a combined near-infrared diffuse optical spectroscopy (DOS) and Magnetic Resonance Imaging (MRI) system for the study of animal model tumors. A combined broadband steady-state and frequency domain optical spectroscopy apparatus was integrated with the MRI. The physiological properties of tissue rendered by MRI, including vascular volume fraction and water, were compared with chromophore concentrations as determined from the parameters obtained by optical measurements. DOS measurements provided oxy-hemoglobin, deoxy-hemoglobin, and water concentration locally in tumors. A method for co-registration of the information obtained by both modalities was developed. Using Monte Carlo simulations, the optically sampled volume was superimposed on the MR images, illustrating which tissue structure was probed optically. Finally, two optical contrast agents, indocyanine green (ICG) and methylene blue (MB), were employed and their kinetics were measured by DOS system from different locations on the tumor and compared with Gd-DTPA enhancement maps obtained from MRI.
authors.affiliation: John Tu and Thomas Yuen Center for Functional Onco-Imaging, University of California Irvine, Irvine, California 92697, USA. ggulsen@uci.edu
authors.forename: Gultekin
authors.initials: G
authors.lastname: Gulsen
authors.forename: Hon
authors.initials: H
authors.lastname: Yu
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Orhan
authors.initials: O
authors.lastname: Nalcioglu
authors.forename: Sean
authors.initials: S
authors.lastname: Merritt
authors.forename: Frederic
authors.initials: F
authors.lastname: Bevilacqua
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Durkin
authors.forename: David J
authors.initials: DJ
authors.lastname: Cuccia
authors.forename: Ryan
authors.initials: R
authors.lastname: Lanning
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Tromberg
mesh_terms: D000818:Animals; D004396:Coloring Agents / Q000494:pharmacology; D003287:Contrast Media / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D007208:Indocyanine Green / Q000494:pharmacology; D007700:Kinetics; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008751:Methylene Blue / Q000494:pharmacology; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D010100:Oxygen / Q000378:metabolism; D011859:Radiography; D051381:Rats; D011916:Rats, Inbred F344; D013053:Spectrophotometry / Q000379:methods*; D013997:Time Factors
chemical_list: D004396:Coloring Agents; D003287:Contrast Media; D004791:Enzyme Inhibitors; D007208:Indocyanine Green; D010100:Oxygen; D008751:Methylene Blue