Overview of PET-CT.
Types of tumors that can be detected by PET-CT
Tumors of various parts of the body, such as colon tumors, lung tumors, liver tumors, pancreatic tumors, gastric tumors, lymphomas, etc.
2.Features of PET-CT examination:
The whole body is all-round, high sensitivity, good resolution, clear image and other characteristics.
3.Principle:
According to the characteristics of rapid tumor growth and metabolism and large uptake of glucose, metabolic analysis can be used to distinguish benign and malignant tumors with high accuracy.
PET-CT examination.
One, two, three, four, you know?
One can't. Can't eat ..
Fasting after 10 p.m. the night before the test (except plain water).
Because the imaging agent used in the examination is 18F-FDG, which is a glucose analogue, it distinguishes normal tissue cells from normal tissue cells by having more glucose uptake and higher metabolism in the lesion. Therefore, it is necessary for the subject to be tested under the condition of low blood sugar, otherwise the increase in blood sugar caused by eating will directly affect the uptake of the imaging agent by the lesion tissue, thereby affecting the examination results.
Two should be less. 1. Talk less
Try to talk as little as possible after the imaging agent is injected.
Speaking requires the use of multiple facial muscles, and if the patient talks too much before the examination, it will lead to an increase in glucose consumption and metabolism in the muscles, causing excessive uptake of imaging agents in normal tissues, resulting in artifacts that affect the diagnosis.
2. Move around less
Try to exercise as little as possible after the imaging agent is injected.
Frequent walking will cause "pseudoglucose" to accumulate too much in muscle tissue, and it is impossible to judge whether it is an increase in muscle metabolism caused by activity or an increase in metabolism caused by lesions, which will affect the accuracy of the examination.
Three is not in a hurry. 1. The examination and waiting should not be urgent
Before the examination, the doctor will ask for a detailed medical history, review the patient's previous medical history records, imaging tests, etc., all in order to better understand the physical condition of the examinee. Because the disease will continue to change, the imaging manifestations of the same disease are not exactly the same, and some of them are the same imaging manifestations but may be different diseases, which requires doctors to understand the relevant disease development process and conduct a comprehensive analysis.
After the injection of the imaging agent, it is necessary to rest for 40-60 minutes, which is to allow the lesion to fully absorb the drug and achieve the best display effect.
2. The inspection process should not be rushed
PET-CT is a comprehensive examination of the whole body and takes about 15-20 minutes. In order to see the lesion more clearly, some subjects also need to be on the machine a second time, and through the changes in the image of the two scans before and after, they can make a more accurate diagnosis of the disease.
3. The inspection report should not be urgent.
After the PET-CT examination, thousands of images will be generated, and the imaging doctors need to analyze these thousands of images one by one to get the examination results, and in order to ensure the accuracy of the examination results, experts will also be invited to review the examination results. Therefore, it is usually not possible to get a full report immediately after the examination.
Fourth, pay attention. 1. Explain the medical history
If the subject has a history of diseases, such as diabetes, tumors, surgery or drug allergies, etc., they need to inform the doctor accurately and bring their previous medical information;
If you are pregnant or breastfeeding, you should also inform your doctor of your condition in advance so that the doctor can deal with it accordingly.
2. Make an appointment
PET-CT examination is special, the imaging agent used is pre-ordered every day, and temporary patients generally do not have extra medicine to do.
3. Drink plenty of water
The imaging agent used in PET-CT examination will be excreted with urine after entering the body of the examinee, so it is necessary to drink plenty of water after the examination to accelerate the metabolism of radioimaging agent in the body and make it expel as soon as possible, and under normal circumstances, all metabolism can be completed in one day.
4. Do not wear metal jewelry and wear clothing containing metal
During PET-CT examination, do not wear clothes with metal ornaments, and take out metal objects on your body, such as belts, keys, mobile phones, watches, necklaces, jewelry, coins, etc., before the examination, so as to prevent obstruction of the examination site and cause missed diagnosis.