Breast cancer detection using phase contrast diffuse optical tomography

Abstract

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.

Automated breast cancer classification using near-infrared optical tomographic images

“…16 Our initial clinical results demonstrate that phase-contrast DOT combined with conventional DOT offers considerably improved sensitivity and specificity compared to that by using conventional DOT alone. 13 In addition, our results show that cellular density and size derived from the scattering spectra can characterize the nature of breast lesions more accurately than the scattering property or scattering amplitude/scattering power. Initial results in 14 breast abnormalities show that malignant tumors can be differentiated from benign lesions with high accuracy, 14 meaning that phase contrast and cellular density/ size together with the functional parameters can provide a more complete spectrum with much improved sensitivity and specificity for accurate characterization of breast lesions.…”

“…As discussed in Ref. 13, it is impossible to distinguish the malignant from the benign cases by just visually examining both absorption and scattering images. However, our automated classification procedure can achieve reasonable classification results using both absorption and scattering coeffi- Fig.…”

“…Using the aforementioned method to classify the images visualized by the MATLAB PDE toolbox, the statistics of the visual examination results over these 35 breast masses ͓biopsy confirmed 11 invasive carcinomas ͑malignant group͒ and 24 benign lesions ͑benign group͔͒ are presented in Table 1. 13 While the results shown in Table 1 are promising, the visual examination process has several drawbacks. First, it is time consuming, because the technician has to manually create MATLAB files to visualize the images.…”

“…These systems have been used to evaluate the potential of our approach through a series of studies designed to quantify the imaging contrast in the normal and abnormal breast and to provide initial assessments of the operating characteristics of the imaging systems for diagnostic decisionmaking in the setting of screen-detected breast lesions. [10][11][12][13][14] Specifically, both absorption and scattering properties of breast tissues can be obtained to sensitively distinguish between normal and abnormal breast tissues. Cysts can be clearly differentiated from solid tumors based on these two properties alone.…”