Real-Time AHO imaging refers to visualizing tracer movement without the requirement to stop and process the tissue. The potential advantage here is that the variable of time between tracer introduction and tissue processing for non-real-time assessment is avoided. For the most part, real-time techniques have focused on small and clinically available tracers (fluorescein, indocyanine green (ICG), or trypan blue) using more clinical and surgical techniques. This is likely because clinical assessment of AHO in patient care would be better real-time since non-real-time methods rely so much upon pathological and histological methods.