Image processing algorithms to facilitate and enhance sentinel node detection using a hand-held gamma ray camera in surgical breast cancer staging

We have developed a miniature scintillation camera to be used in surgical cancer staging. The availability of such a compact hand-held gamma camera may in certain cases improve localization of the sentinel lymph node and reduce the duration of a surgical breast cancer staging procedure. We have investigated image processing algorithms applied to planar images that may improve node detection capabilities for breast cancer staging. We have also studied contrast enhancement methods that may be able to identify nodes that would otherwise be missed. Exposure duration for a given camera position can be adaptively shortened or increased by using an optical flow algorithm to estimate camera motion with respect to the current frame. By determining if the camera is in motion or not, the exposure time may be increased to allow more image counts to accumulate at a given camera position. Adaptive exposure time may improve the ease of use of the hand-held camera, and allow regions of interest to be imaged more effectively. We feel that these image processing techniques can improve the utility of a hand-held gamma ray imager for sentinel lymph node detection during breast cancer staging.