Hyperspectral SFDI, J. Biomedical Optics Publication By Mohammad Torabzadeh

Posted on July 3, 2019 by rrowland

We introduce a method for quantitative hyperspectral optical imaging in the spatial frequency domain (hs-SFDI) to image tissue absorption (μa) and reduced scattering ( μs′) parameters over a broad spectral range. The hs-SFDI utilizes principles of spatial scanning of the spectrally dispersed output of a supercontinuum laser that is sinusoidally projected onto the tissue using a digital micromirror device. A scientific complementary metal–oxide–semiconductor camera is used for capturing images that are demodulated and analyzed using SFDI computational models. The hs-SFDI performance is validated using tissue-simulating phantoms over a range of μa and μs′ values. Quantitative hs-SFDI images are obtained from an ex-vivo sample to spatially resolve concentrations of oxy-, deoxy-, and met-hemoglobin, as well as water and fat fractions. Our results demonstrate that the hs-SFDI can quantitatively image tissue optical properties with 1000 spectral bins in the 580- to 950-nm range over a wide, scalable field of view. With an average accuracy of 6.7% and 12.3% in μaand μs′, respectively, compared to conventional methods, hs-SFDI offers a promising approach for quantitative hyperspectral tissue optical imaging.

Published in the Journal of Biomedical Optics July 2019, by Mohammad Torabzadeh

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Measuring Whole Breast Radiation, MHSRS 2018 Poster Presentation By Anais Leproux

Posted on August 13, 2018 by lebc

Radiotherapy is a critical component in the treatment of breast cancers (1).  During radiation therapy, patients develop varying degrees of erythema with some developing dry or moist desquamation. Additionally, patients can develop permanent discoloration of the skin and thickening of the breast tissue (2). Quantifying radiation-induced skin changes during and after radiation is challenging, since standardized scoring systems (RTOG Radiation Morbidity Scoring Scheme and CTCAE v.4) are subjective and provide only a qualitative evaluation of the skins visual appearance (3).  Additionally, there is currently no predictor for patients who develop more severe Grade 3 and 4 acute and late toxicities. Having a non-invasive quantitative technique to reproducibly and objectively measure acute and late radiation-induced skin changes is needed in the clinic.

The objectives of this study are to characterize radiation-induced skin changes during and after whole breast radiation using a contact-less operator-independent optical imaging device, Spatial Frequency Domain Imaging (SFDI). A reliable and quantitative method of risk assessment for radiation induced skin reactions would help in individualizing the management and care of patients undergoing radiotherapy. In the long term, it could also provide oncologists with a relatively simple, risk-free bedside tool that can help inform medical decisions on radiation protocols (such as dose, frequency and duration) thereby minimizing unnecessary skin toxicity while providing adequate treatment efficacy.

Presented at Military Health System Research Symposium, August 2018

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