Indocyanine green emits near-infrared light after illumination because it binds plasma proteins. Specialized cameras detect this emitted signal and convert it into a visual display that can be interpreted during the operation. Because imaging occurs while surgery is underway, the technique supplies dynamic rather than delayed information about structures and tissue behavior.
Plasma-protein binding enables indocyanine green to produce a detectable near-infrared fluorescent signal after illumination. That signal can then be captured by specialized imaging equipment and displayed for the surgical team. This mechanism supports visualization of circulation-related information, including blood flow and tissue perfusion, while the procedure is in progress.
Intravenous administration introduces indocyanine green through the circulation, whereas local administration places it at a selected operative region. Using either route allows the imaging approach to be adapted to the information being sought. In both cases, specialized illumination and camera systems detect the resulting fluorescence for real-time surgical visualization.
The workflow requires illumination that excites the dye, together with a specialized camera capable of detecting near-infrared emission. The camera presents the signal visually during the operation, allowing the surgical team to examine blood flow, tissue perfusion, lymphatic drainage, or selected anatomical structures without ionizing radiation.
Its applications center on decisions where visualizing circulation or anatomy matters. Surgeons can assess organ and tissue viability, identify vessels and bile ducts, map lymphatic drainage, and guide tumor or reconstructive procedures. These uses make the method relevant when operative planning must incorporate immediate information about perfusion, drainage, or anatomical location.
Unlike imaging that relies on ionizing radiation, intraoperative ICG fluorescence provides optical feedback during the operation without that form of radiation. Its value lies in showing changing blood flow, perfusion, or drainage as surgery proceeds, so clinicians can incorporate observed information into decisions about tissue viability and anatomical guidance in the operative setting.