Sources of Absorption and Scattering Contrast for Near-Infrared Optical Mammography

Albert E Cerussi,Andrew J Berger,Frederic Bevilacqua,Natasha Shah,Dorota Jakubowski,John Butler,Randall F Holcombe,Bruce J Tromberg

doi:10.1016/s1076-6332(03)80529-9

Abstract

Rationale and Objectives Near-infrared (NIR) diffuse optical spectroscopy and imaging may enhance existing technologies for breast cancer screening, diagnosis, and treatment. NIR techniques are based on sensitive, quantitative measurements of functional contrast between healthy and diseased tissue. In this study, the authors quantified the origins of this contrast in healthy breasts. Materials and Methods A seven-wavelength frequency-domain photon migration probe was used to perform noninvasive NIR measurements in the breasts of 28 healthy women, both pre- and postmenopausal, aged 18–64 years. A diffusive model of light transport quantified oxygenated and deoxygenated hemoglobin, water, and lipid by their absorption signatures. Changes in the measured light-scattering spectra were quantified by means of a “scatter power” parameter. Results Substantial quantitative differences were observed in both absorption and scattering spectra of breast as a function of subject age. These physiologic changes were consistent with long-term hormone-dependent transformations that occur in breast. Instrument response was not adversely affected by subject age or menopausal status. Conclusion These measurements provide new insight into endogenous optical absorption and scattering contrast mechanisms and have important implications for the development of optical mammography. NIR spectroscopy yields quantitative functional information that cannot be obtained with other noninvasive radiologic techniques.

Highlights

MethodsA seven-wavelength frequency-domain photon migration probe was used to perform noninvasive NIR measurements in the breasts of 28 healthy women, both pre- and postmenopausal, aged 18 – 64 years
Substantial quantitative differences were observed in both absorption and scattering spectra of breast as a function of subject age
These physiologic changes were consistent with long-term hormone-dependent transformations that occur in breast

Summary

Methods

A seven-wavelength frequency-domain photon migration probe was used to perform noninvasive NIR measurements in the breasts of 28 healthy women, both pre- and postmenopausal, aged 18 – 64 years. The instrument probe, slightly larger than a US probe (Fig 1), was the only item placed in contact with the subject. It consisted of a sealed APD module and an optical fiber placed 22 mm from the APD. The probe was placed on the breast with minimal pressure and only the force of gravity; no compression was used. In this configuration, we estimate that the mean sampling depth was approximately 1 cm below the skin. Error bars in the figures and tables represent the standard deviations (SDs) of repeated measurements

Results

Discussion

Conclusion