Optical imaging is widely used in clinical medicine. It has the advantages of harmless, non-invasive, high sensitivity and multi object imaging in vivo. With the continuous development and innovation of fluorescent developer, fluorescence imaging is becoming a tool for navigation in surgery.
Fluorescence imaging technology can real-time identify and identify target structures and tissues in surgery, provide accurate and accurate target images for surgeons, and guide accurate operation.
生物体内具有大量的血红蛋白、水和脂质，在650 nm-900 nm的光谱范围内吸收系数较低，该波段成为生物体的光学窗口。
There are a large amount of hemoglobin, water and lipid in the organism, and the absorption coefficient is low in the spectral range of 650 nm-900 nm. This band becomes the first optical window of organism.
Near infrared fluorescence imaging uses the near infrared excitation light source to irradiate the fluorescence molecules, which excites the photon signals with different spectral characteristics, and then the signals are captured by the camera for imaging. Because of the long wavelength of near infrared light, it is in the first window of biological optics, absorbs less and penetrates deeply, so as to improve the imaging depth.
At present, the application technology of indocyanine green based on near infrared fluorescent agent is becoming more and more mature. The developer has been approved by FDA and CE. It has been widely used in many fields, such as tissue perfusion, tumor location, sentinel lymph node detection and so on.
The fluorescent developer, indocyanine green, binds to plasma proteins by intravenous injection and releases different wavelengths of fluorescence through the excitation of near infrared light at about 805 nm wavelength.
The imaging system processes the captured fluorescence signal through the algorithm, and displays the high definition white light, the fluorescence or the superposition image on the screen in real time. Compared with the traditional organic dyes, the real-time fluorescent display method has higher contrast and better recognition effect on target tissues, and avoids dye dispersion in the later stage of surgery.
At present, near infrared fluorescence imaging technology to achieve real-time display of the fluorescent image during operation, and according to the operation needs of fast switching mode, as an important role in the operation of navigation, help patients accurate and fast operation. At present, the technology is mainly used:
The development of lymph nodes in endometrial cancer, cervical cancer, early ovarian cancer and perineal cancer
Urologic surgery: renal tumor markers, prostatectomy, and prostatic lymph node development
Department of hepatobiliary surgery: liver tumor boundary markers, extrahepatic bile duct angiography, liver segmental angiography
Gastrointestinal surgery: perfusion of the stomach, esophagus and intestine, contrast of gastric and intestinal lymph nodes
Department of thoracic surgery: lymph node development and pulmonary angiography
Cardiac surgery: in situ coronary artery bypass grafting and On pump coronary artery bypass grafting
Breast surgery: sentinel lymph node localization in breast cancer, prevention of lymphedema in breast cancer radical mastectomy, and observation of blood flow in breast reconstruction flap
Plastic surgery and vascular surgery: the measurement of perforator perfusion range, the selection of optimal perforator, the detection of microcirculation, the location of perforator, and the blood perfusion imaging of skin and tissue