A multimodal sono-contrast NIR spectroscopy system for breast cancer Diagnosis: System design and safety considerations

This paper presents a novel multimodal imaging system, which combines optical spectroscopy, ultrasonography and acoustic radiation force (ARF) for improving diagnosis of breast cancer based on noninvasive interrogation of vasculature. System design including both hardware and software is described in detail. Patient safety related considerations are also addressed in this paper. Calibrations and tests have been performed accordingly. Based on safety guidelines, the maximum exposure to skin for laser was controlled within 0.2 W·cm^-2; exposure from ARF fields were maintained below the FDA diagnostic limit (0.72 W·cm^-2), and electrical leakage was controlled below 300 μA. This multimodal system has the potential to improve tumor detection by deploying ARF to produce a measurable difference in the dynamic behavior of the tissue blood supply environment as interrogated by optical spectroscopy, which was demonstrated to be highly diagnostic in a murine tumor model. Pilot clinical study is being carried out.