Illustration of the use of SPY to assist in the design of transverse abdominus musculocutaneous (TRAM) flap for breast reconstruction in two patient cases. Panel A shows a schematic illustration of the best perfused tissue in the TRAM flap for Case 1. This flap was designed based on the corresponding SPY image (Panel C), which demonstrated good perfusion in zone 1, clearly definable and in contrast to the poor perfusion across the midline in zone 3. In contrast, Panel B shows the schematic flap design for the TRAM flap in Case 2 based on the SPY image (Panel D), which demonstrated good perfusion in zone 1 and to a clearly definable point in zone 3 (dotted line). Lateral to this point in zone 3, fluorescence on SPY remained poor, indicating areas of relative ischemia and potential tissue loss. This information was originally published in Can J Plast Surg 2011;19(1):e1-e5.