Portable near-infrared diffusive light imager for breast cancer detection

• Published in: Journal of Biomedical Optics 2004-05, Vol.9 (3), p.504-510
• Main Authors: Chen, Nan Guang, Huang, Minming, Xia, Hongjun, Piao, Daqing, Cronin, Edward, Zhu, Quing
• Format: Article
• Language: English
• Subjects: Algorithms; avalanche photodiodes; breast cancer; Breast Neoplasms - diagnosis; Breast Neoplasms - diagnostic imaging; diffusive imaging; dynamic range; Equipment Design; Female; Humans; Image Enhancement - instrumentation; Image Enhancement - methods; Middle Aged; optical switches; Reproducibility of Results; Sensitivity and Specificity; Spectrophotometry, Infrared - instrumentation; Spectrophotometry, Infrared - methods; Subtraction Technique; Tomography, Optical - instrumentation; Tomography, Optical - methods; Ultrasonography, Mammary - instrumentation; Ultrasonography, Mammary - methods
• ISSN: 1083-3668; 1560-2281
• DOI: 10.1117/1.1695410

We present a frequency-domain near-infrared optical tomography system designed for breast cancer detection, in conjunction with conventional ultrasound. It features fast optical switching, three-wavelength excitations, and avalanche photodiode as detectors. Laser diodes at 660, 780, and 830 nm are used as light sources and their outputs are distributed sequentially to one of nine source fibers. An equivalent 130-dB isolation between electrical signals from different source channels is achieved with the optical switches of very low crosstalk. Ten detection channels, each of which includes a silicon avalanche photodiode, detect diffusive photon density waves simultaneously. The dynamic range of an avalanche photodiode is about 20 to 30 dB higher than that of a photomultiplier tube, thus eliminating the need for multistep system gain control. The entire system is compact in size and fast in data acquisition (less than 2 sec for a complete scan). Calibration and the clinical experiment results are presented in the paper. ©