Use of SPY to identify areas of poor perfusion prior to reconstruction. The colorized SPY image of the left breast (Panel A) shows a region of low fluorescence (dark blue), corresponding to the nipple-areola complex (NAC). Numbers reflect quantification of absolute fluorescence values. Based on clinical judgment of tissue viability (including appearance of skin and presence of bleeding at tissue edge), the area identified by SPY was not removed. Following reconstruction (Panel B), the NAC appears dusky inferior to the incision. Ultimately, the NAC region identified by SPY as having poor perfusion developed necrosis (Panel C) and required return to the OR for debridement and removal of the NAC (Panel D).