Laser optoacoustic imaging system for detection of breast cancer

We designed, fabricated and tested the laser optoacoustic imaging system for breast cancer detection LOIS-64, which fuses optical and acoustic imaging techniques in one modality by utilizing pulsed optical illumination and ultrawide-band ultrasonic detection of resulting optoacoustic OA signals. The system was designed to im- age a single breast slice in craniocaudal or mediolateral projection with an arc-shaped array of 64 ultrawide-band acoustic transducers. The system resolution on breast phantoms was at least 0.5 mm. The single-channel sensitivity of 1.66 mV/Pa was estimated to be suffi- cient for single-pulse imaging of 6t o 11 mm tumors through the whole imaging slice of the breast. The implemented signal processing using the wavelet transform allowed significant reduction of the low- frequency LF acoustic noise, allowed localization of the optoacous- tic signals from tumors, and enhanced the contrast and sharpened the boundaries of the optoacoustic images of the tumors. During the pre- liminary clinical studies on 27 patients, the LOIS-64 was able to visu- alize 18 out of 20 malignant lesions suspected from mammography and ultrasound images and confirmed by the biopsy performed after the optoacoustic tomography OAT procedure. © 2009 Society of Photo