title: Rapid determination of oxygen saturation and vascularity for cancer detection.
abstract: A rapid heuristic ratiometric analysis for estimating tissue hemoglobin concentration and oxygen saturation from measured tissue diffuse reflectance spectra is presented. The analysis was validated in tissue-mimicking phantoms and applied to clinical measurements in head and neck, cervical and breast tissues. The analysis works in two steps. First, a linear equation that translates the ratio of the diffuse reflectance at 584 nm and 545 nm to estimate the tissue hemoglobin concentration using a Monte Carlo-based lookup table was developed. This equation is independent of tissue scattering and oxygen saturation. Second, the oxygen saturation was estimated using non-linear logistic equations that translate the ratio of the diffuse reflectance spectra at 539 nm to 545 nm into the tissue oxygen saturation. Correlations coefficients of 0.89 (0.86), 0.77 (0.71) and 0.69 (0.43) were obtained for the tissue hemoglobin concentration (oxygen saturation) values extracted using the full spectral Monte Carlo and the ratiometric analysis, for clinical measurements in head and neck, breast and cervical tissues, respectively. The ratiometric analysis was more than 4000 times faster than the inverse Monte Carlo analysis for estimating tissue hemoglobin concentration and oxygen saturation in simulated phantom experiments. In addition, the discriminatory power of the two analyses was similar. These results show the potential of such empirical tools to rapidly estimate tissue hemoglobin in real-time spectral imaging applications.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America.
authors.forename: Fangyao
authors.initials: F
authors.lastname: Hu
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America.
authors.forename: Karthik
authors.initials: K
authors.lastname: Vishwanath
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America.
authors.forename: Justin
authors.initials: J
authors.lastname: Lo
authors.affiliation: Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina, United States of America.
authors.forename: Alaattin
authors.initials: A
authors.lastname: Erkanli
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America.
authors.forename: Christine
authors.initials: C
authors.lastname: Mulvey
authors.affiliation: Division of Otolaryngology-Head and Neck Surgery, Duke University Medical Center, Durham, North Carolina, United States of America ; Section of Otolaryngology-Head and Neck Surgery, Veterans Administration Medical Center, Durham, North Carolina, United States of America.
authors.forename: Walter T
authors.initials: WT
authors.lastname: Lee
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina, United States of America.
authors.forename: Nimmi
authors.initials: N
authors.lastname: Ramanujam
mesh_terms: D000465:Algorithms; D001943:Breast Neoplasms / Q000098:blood supply / Q000175:diagnosis / Q000378:metabolism; D003198:Computer Simulation; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006258:Head and Neck Neoplasms / Q000098:blood supply / Q000175:diagnosis / Q000378:metabolism; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D009369:Neoplasms / Q000098:blood supply* / Q000175:diagnosis* / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000175:diagnosis / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D019047:Phantoms, Imaging; D011874:Radiometry / Q000295:instrumentation / Q000379:methods*; D002583:Uterine Cervical Neoplasms / Q000098:blood supply / Q000175:diagnosis / Q000378:metabolism; D002578:Uterine Cervical Dysplasia / Q000098:blood supply / Q000175:diagnosis / Q000378:metabolism
chemical_list: D006454:Hemoglobins; D010100:Oxygen