Development of a Visible–Near Infrared Projected Multispectral Imaging System for Intraoperative Breast Tumor Margin Assessment

A visible–near infrared (VIS–NIR) projected multispectral imaging (Proj-MSI) system consisting of an MSI subsystem and a compact projector for intraoperative breast tumor margin assessment was developed. MSI with an average spectral resolution of 24 nm was realized through sequential illumination of 26 sets of VIS–NIR light-emitting diodes and synchronized single NIR-sensitive camera image capture. Rapid (~1 min) tumor margin delineation revealed significantly (p < 0.01, Student's t-test) reduced reflectivity associated with breast tumor. Speeded-up robust features algorithm-based field of view calibration allowed the MSI identified tumor margins to be projected directly onto the breast-conserving surgery (BCS) surgical cavity with a projection error of < 1 mm. Besides, the projected tumor margin boundaries were outlined using Indian ink to simulate breast tumor removal, demonstrating the potential of the Proj-MSI system developed for intraoperative tumor margin assessment during BCS.