A dual-mode simultaneous bilateral optical imaging system for breast cancer detection

System design, performance characteristics and representative clinical findings are described for a second generation dynamic near-infrared optical tomography breast imager that examines both breasts simultaneously under conditions of rest and controlled provocation. Novel elements of the system include incorporation of high-density optical sensing heads (8192 channels) that include feedback-controlled force-sensing articulating members, their capacity to conform to a wide range of breast sizes, and the ability to perform opto-mechanical scans in the seated position. The new sensor heads employ a set of stepper linear motors to adjust the applied force with high spatial selectivity and rapid response time, and strain gauges to provide for active control. A user interface has been developed to support two different modes of sensing head control. In both modes, optical measurements from all sensing channels are continuously recorded. In all, the developed system provides three sets of measurements: optical, applied force, and deformation. The high sensor density combined with fine articulation supports exploration of the hemodynamic response of the breast under a wide range of protocols together with measures of Young's modulus and quasi-elastic plastic deformation. Representative clinical findings obtained from healthy and tumor breasts at rest and during controlled provocations are presented.