Have you ever heard of a nuclear medicine department in a hospital? When we walk into a hospital, we all know about internal medicine and surgery, and we also know about laboratory and radiology departments, and we know which department to go to when we need to see a doctor. But when it comes to nuclear medicine, many people may not have heard of it. What does nuclear medicine do? Does it examine diseases or treat diseases? What kind of diseases can be diagnosed and treated? Nuclear medicine is a department that uses nuclear medicine technology to diagnose and treat diseases. However, due to the economic backwardness of our country, nuclear medicine departments are mostly concentrated in large hospitals, and few small hospitals have nuclear medicine departments. What is nuclear medicine? Nuclear medicine is a science of diagnosing and treating diseases by using drugs marked with radionuclides, which is a product of medical modernization and the application of nuclear technology in the field of medicine. Nuclear medicine is an emerging discipline that is developing very rapidly. Radionuclide tracer technology is the most basic technology of nuclear medicine. What is included in nuclear medicine? Nuclear medicine consists of two major components: nuclear diagnosis and nuclear therapy. Among them, nuclear diagnosis includes nuclear imaging, non-imaging functional examination and in vitro radioimmunoassay. What are the nuclear examinations? It includes γ-photography, SPECT, PET, PET/CT imaging, etc. What are γ-photography, SPECT, PET, and PET/CT? γ-photography, SPECT, PET, PET/CT are both the names of the examinations and the equipment used to perform them. γ-photography is done by γ-camera, which is an imaging equipment to detect the distribution of radionuclides in the body, and can understand the static distribution of radioactive drugs in the body, as well as the dynamic change process of radioactive drugs in the body, and the systemic distribution of radioactive drugs. SPECT is tomographic imaging based on γ-photography, PET is ECT for detecting positronic radiopharmaceuticals, and PET/CT is CT positioning function introduced on the basis of PET. What is SPECT examination? It is actually a γ camera with one or more probes rotating 360° around a patient’s organ, acquiring a frame at certain angles during the rotation, then superimposing the images and reconstructing them into cross-sectional, coronal, sagittal or any desired tomographic or sectional images of the organ in different directions. SPECT can perform both planar and dynamic (functional) imaging of organs. What is a PET test? PET, or Positron Emission Computed Tomography, is the most advanced medical technology in the world. PET is one of the most advanced medical imaging devices in the world, and is the most advanced medical imaging technology that can perform functional and metabolic imaging of the human body at the cellular and molecular levels. The application of PET in clinical medicine is mainly focused on three major fields: malignant tumor, neurology and cardiovascular system. What is PET/CT examination? PET/CT, the most advanced positron emission tomography and advanced high-resolution multi-row spiral CT, is a large functional metabolic and molecular imaging diagnostic device that combines the functions of PET and CT at the same time, achieving the true sense of complementary advantages (1+1>2). The diagnostic accuracy of PET/CT is significantly better than that of PET alone or multi-row CT, which is an epoch-making milestone in the history of medical imaging diagnostic technology. At the same time, PET/CT is one of the most important high technologies in the international life sciences (brain function, gene and protein function imaging diagnosis) research and its clinical application. What diseases can be examined by nuclear medicine? It can understand the function of major organs such as heart, kidney, liver, gallbladder and thyroid gland; it can understand the blood perfusion of heart muscle, brain, lung and other organs; it can understand and determine the existence of tumor and lymphatic metastasis and bone metastasis, etc. All the functions, blood flow and metabolism of organs and tissues concerned. Different tests are done to understand different functional and metabolic purposes using different kinds of radiopharmaceuticals, and the labeled radionuclides are often very few. There are more types of imaging in nuclear medicine than in any other imaging method. There are static and dynamic imaging; local and whole-body imaging; planar and tomographic imaging; early and delayed imaging; positive and negative imaging; and various interventional imaging. Nuclear medicine imaging is very different from CT, MR, B-ultrasound and other imaging examinations, and is fundamentally different. Nuclear medicine imaging depends on the blood flow, cell function, cell number, metabolic activity and drainage of organs or tissues, and is a kind of functional imaging, supplemented by the observation room of anatomical changes. A very safe nuclear medicine examination? It can be said that it is very safe. There are three main factors that cause unsafe imaging examinations: 1 is the influence of the chemical composition of the imaging agent, contrast agent, contrast agent and other drugs, mainly allergic reactions and toxic reactions; 2 is the radiation caused by radioactivity; 3 is the damage and pain caused by the operation process and even danger when conducting the examination. The nuclide tracer technology is very sensitive, and the chemical composition of the radioactive drugs used is so small that it is almost negligible, so it will not cause any allergic and toxic reactions. Secondly, the nuclide used in nuclear diagnosis mainly emits gamma rays, which are characterized by strong penetrating ability and little damage to the body. For example, the absorbed dose of bladder urinary reflux imaging in nuclear medicine is only 1% of that of X-ray cystography, and X-ray is safe for patients, not to mention nuclear medicine imaging. The procedure of nuclear medicine examination is only intravenous or oral administration of radioactive drugs, which is often very small, without the damage and pain and risk caused by intubation and other operations. Nonetheless, nuclear medicine has strict requirements and regulations to further reduce the occurrence of adverse reactions. Nuclear medicine tests can save patients money Nuclear medicine functional measurements are about a few dozen dollars, imaging tests are mostly a few hundred dollars, but there are also tests that cost several thousand dollars or even about ten thousand dollars, which intuitively feels very expensive indeed. The price depends largely on the cost. Whether such an expensive test is worth it or not depends on how useful it is in the overall diagnostic and treatment process and whether it ultimately saves or costs the patient money. For example, whole body bone imaging in nuclear medicine is a very sensitive method for early detection of tumor bone metastasis, and it costs several hundred dollars to do one. However, it can detect bone metastasis at an early stage and can avoid unnecessary surgeries. The expense of reducing unnecessary surgery is far greater than the expense of doing bone imaging. Not to mention the surgery that should not be done, the damage caused to the patient is immeasurable. Another example is that many patients with coronary artery disease avoid unnecessary catheter interventions when they have nuclear medicine myocardial perfusion imaging. Nuclear medicine exams cost about$2,000, and catheter interventions often cost tens of thousands of dollars. And reducing the risk of restenosis due to catheterization and the occurrence of restenosis after the procedure is even more critical to the patient’s prognosis. Therefore, the cost of the test cannot be measured simply by the cost of the test, but usually by the “value for money”. Rather than saying whether the test is expensive, we should consider whether it is worthwhile. Radionuclide therapy is an important part of nuclear medicine. Radionuclide therapy is a drug that is introduced into the patient’s body by oral or intravenous injection. This drug is different from ordinary drugs, it is a drug containing radionuclides, like a missile, which can be gathered wherever it is pointed, and the radionuclides in the diseased tissue will emit a kind of ray to kill the diseased cells, thus achieving the purpose of treating the disease. The major difference between radiation therapy and ordinary radiation therapy is that the source of radiation in the latter is a radiation device, and the radiation is irradiated from outside the body to the diseased tissue in the body, so radiation therapy is also called external radiation therapy. The radionuclide in internal irradiation therapy is completely different from the type of radiation used for imaging, and is characterized by strong killing power and short range, which can only kill the diseased tissues within 2~3mm without affecting the surrounding normal tissues, just like a missile directed to destroy the target.