Rapid determination of oxygen saturation and vascularity for cancer detection

• Published in: PloS one Vol. 8; no. 12; p. e82977
• Main Authors: Hu, Fangyao, Vishwanath, Karthik, Lo, Justin, Erkanli, Alaattin, Mulvey, Christine, Lee, Walter T, Ramanujam, Nimmi
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 16.12.2013; Public Library of Science (PLoS)
• Subjects: Algorithms; Anemia; Biology; Biomedical engineering; Biopsy; Breast Neoplasms - blood supply; Breast Neoplasms - diagnosis; Breast Neoplasms - metabolism; Cancer; Cancer therapies; Cervical cancer; Cervical Intraepithelial Neoplasia - blood supply; Cervical Intraepithelial Neoplasia - diagnosis; Cervical Intraepithelial Neoplasia - metabolism; Computer Simulation; Diagnosis; Early Detection of Cancer - methods; Empirical analysis; Engineering; Estimation; Female; Head and neck; Head and Neck Neoplasms - blood supply; Head and Neck Neoplasms - diagnosis; Head and Neck Neoplasms - metabolism; Hemoglobin; Hemoglobins - analysis; Humans; Imaging systems; Linear equations; Mathematical models; Medical diagnosis; Medical prognosis; Medical screening; Mimicry; Monte Carlo simulation; Morphology; Neoplasms - blood supply; Neoplasms - diagnosis; Neoplasms - metabolism; Neovascularization, Pathologic - diagnosis; Neovascularization, Pathologic - metabolism; Nonlinear equations; Oncology; Optical properties; Optics; Otolaryngology; Oxygen; Oxygen - metabolism; Oxygen Consumption - physiology; Oxygen content; Oxygen saturation; Phantoms, Imaging; Physics; Physiology; Radiation therapy; Radiometry - instrumentation; Radiometry - methods; Reflectance; Saturation; Spectra; Spectrum analysis; Tissue analysis; Tissues; Uterine Cervical Neoplasms - blood supply; Uterine Cervical Neoplasms - diagnosis; Uterine Cervical Neoplasms - metabolism; North Carolina; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0082977

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.