PROCEEDINGS ARTICLE | February 13, 2007
Proc. SPIE. 6434, Optical Tomography and Spectroscopy of Tissue VII
KEYWORDS: Breast, Refractive index, Breast cancer, Tumors, Tissues, Scattering, Light scattering, Reconstruction algorithms, Absorption, Diffuse optical tomography
In this report, a phase-contrast diffuse optical tomography system, which can measure the refractive indices
of human breast masses in vivo, is described. To investigate the utility of phase-contrast diffuse optical
tomography (PCDOT) for differentiation of malignant and benign breast masses in humans, and to compare
PCDOT with conventional diffuse optical tomography (DOT) for analysis of breast masses in humans. 35
breast masses were imaged in 33 patients (mean age = 51 years; range 22-80 years) using PCDOT. Images
characterizing the tissue refractive index, absorption and scattering of breast masses were obtained with a
finite element-based reconstruction algorithm. The accuracies of absorption and scattering images were
compared with images of refractive index in light of the pathology results. Absorption and scattering images
were unable to accurately discriminate benign from malignant lesions. Malignant lesions tended to have
decreased refractive index allowing them to discriminate from benign lesions in most cases. The sensitivity,
specificity, false positive value, and overall accuracy for refractive index were 81.8%, 70.8%, 29.2%, and
74.3%, respectively. Overall we show that benign and malignant breast masses in humans demonstrate
different refractive index and differences in refractive index properties can be used to discriminate benign
from malignant masses in patients with high accuracy. This opens up a new avenue for improved breast
cancer detection using NIR diffusing light.
