PET-CT (positron emission computed tomography)It is an advanced medical imaging technology that combinesPositron emission tomography (PET)andComputed tomography (CT)has the advantage of being able to simultaneously provideFunctional metabolic informationandPrecise anatomical positioning. It is mainly used for early diagnosis, staging and efficacy evaluation of tumors, cardiovascular diseases and neurological diseases. The content will focus on its principles, clinical applications, advantages and limitations, and list mainstream manufacturers and equipment models.

How PET-CT worksBased on the metabolic distribution of radioactive tracers (such as fluorodeoxyglucose, FDG) in the human body. The PET part generates metabolic images by detecting gamma rays released by tracers, while the CT part provides high-resolution anatomy. After the two are combined, doctors can pinpoint abnormal metabolic areas. For example, due to high metabolism, tumor cells will take up a large amount of FDG, showing "highlight" signals in the image. This technology significantly improves the detection rate of small lesions and is especially valuable in early cancer screening.

clinical applicationIn recent years, PET-CT has become the “gold standard” for tumor diagnosis and treatment. In addition to being used for staging and efficacy monitoring of lung cancer, lymphoma, etc., it can also evaluate myocardial survival rate and brain metabolic changes in Alzheimer's disease. Compared with traditional imaging, its advantage is that it can obtain both functional and structural information in one scan, reducing missed diagnoses. However, it should be noted that the radiation dose is high (about 2 times that of CT) and expensive (a single examination costs about 8,000-12,000 yuan), and the indications need to be strictly controlled.

technical limitationsIncluding insufficient sensitivity for some low-metabolizing tumors (such as prostate cancer) and the timeliness of tracer preparation (half-life only 110 minutes). Currently, the world’s major manufacturers includeSiemens (Siemens Biograph series),General Electric (GE Discovery Series)andPhilips (Philips Vereos series). Domestic United Imaging Medical (uMI series) has also gradually emerged, and its equipment performance is close to the international level.

Taken together, PET-CT is an important breakthrough in modern medical imaging, but its application needs to weigh the costs and benefits. In the future, with the advancement of tracer research and development and artificial intelligence image analysis, its accuracy and popularity are expected to be further improved. Patients should choose the examination plan rationally under the guidance of their doctor.

Quote sources:
1. "Nuclear Medicine and Molecular Imaging" (People's Medical Publishing House, 2020)
2. "PET-CT Clinical Operation Guidelines" by the Nuclear Medicine Branch of the Chinese Medical Association
3. Technical white papers published by manufacturers (official websites of Siemens, GE, etc.)
4. Medical device data from the National Medical Products Administration