have you ever skipped meals for the first half of the day? Have you ever had the experience of pouring water before inspection?
required reading before MRI
MRI is the most effective imaging diagnostic method for the diagnosis of diseases such as brain and spinal cord, which can detect tumors, cerebral infarction, cerebral hemorrhage, brain abscess, cerebral cysticercosis and congenital cerebral vascular malformation at an early stage, and also determine the types and causes of hydrocephalus. Patients often have a headache with pleural effusion. If you want to know whether the pleural effusion is blood or water, you should also check it according to the magnetic resonance imaging.
although the word "nuclear" is used in nuclear magnetic resonance, it has nothing to do with the radiation that everyone is worried about. Since MRI is not harmful to patients' health, why are there more precautions in MRI than in CT?
because the magnetic field in the nuclear magnetic resonance chamber is too strong.
In the nuclear magnetic resonance examination room, everyone can understand the instrument as "a big magnet". Many well-known metal objects are forbidden to be brought into the magnetic vibration chamber. Valuables such as glasses with a big gold chain and a big gold watch with gold edges are symbols of status and wealth. If you bring them into the nuclear magnetic room, they will be attracted to the big magnet and cannot be taken off. The watch will also change its accuracy under the action of a "big magnet".
There are also some metals (except titanium alloy used in surgery) that are difficult to disassemble, such as gold teeth, heart stents and IUDs. If you carry these non-detachable objects into the nuclear magnetic room with high field strength, it may cause local bleeding due to the attraction of the instrument, which will seriously threaten life safety.
Therefore, for the sake of property safety and personal safety, you must hand it in truthfully and inform the imaging doctor before doing nuclear magnetic resonance imaging.
Besides these well-known metal objects, if you have tattoos for examination, you should also pay attention!
The tattoo mentioned here refers to the one containing heavy metals in a small workshop. These heavy metal components will also react with the magnetic field, causing skin irritation or burns. Before doing MRI, doctors usually ask patients if they have tattoos, which is also to ensure the personal safety of patients. Of course, it doesn't mean that all patients with tattoos can't have an MRI, but still look at the materials. Black tattoos, most of which are carbon powder substances, so they do not contain metal components; However, due to the limitation of the current production process of tattoo pigments, color pigments will contain "metal components", but qualified dyes do not contain "heavy metals", which has little impact on nuclear magnetism. So it's best to find out whether the material you tattooed on your body is "safe" and then actively communicate with the imaging doctor.
You must read before CT examination
You can't eat before examination, and you need to drink water before examination ...
Everyone seems to be used to these problems. Sometimes, even if the CT examination is scheduled for five or six in the afternoon the next day, you can bear to be hungry this time, and you can drink water for brunch.
is that what you did? Whether to eat or drink water before the inspection, first of all, we must find out why, and never starve for nothing!
"fasting is necessary for CT". The main purpose of the doctor's order not to eat is to avoid allergic reactions. When doing CT, especially enhanced CT, it may lead to allergic reaction. After eating, it may cause vomiting, and the vomit may be sucked back into the trachea, causing choking or obstruction, which is dangerous.
however, it's not good to skip meals for a long time, because skipping meals and having no energy may increase the possibility of allergic reactions. The correct posture of not eating should be not eating for 3-4 hours before the examination. If it is five or six o'clock in the afternoon, you can have lunch normally, just don't eat for 3-4 hours before CT.
after eating, let's look at drinking water. Not all CT scans have to drink water until they are full.
why do some CT need to drink water? Drinking water is to support your hollow organs, so that the "instrument" can see more clearly, that is, better imaging, which is beneficial for doctors to check. CT examination of digestive tract organs, such as stomach, esophagus, small intestine and bladder, is a typical examination that needs drinking water. (ps: Tumors will not be supported by drinking water)
Some CT examinations are supported without drinking water, such as thyroid CT examination and chest CT examination of lung cancer/pulmonary nodules. There is absolutely no need to drink so much water before the examination, because water has no effect on these organs during the examination.
besides drinking plenty of water, there is another way to support yourself with qi. Patients bring a bottle of soda or coke, which tastes better than water, and don't need to drink too much. After half a bottle or a bottle, carbonic acid enters the human body and becomes carbon dioxide. Without burping, it will also play the same role as a large amount of water, making the imaging clearer.
PET-CT must be read before examination
compared with conventional CT, PET-CT is more sensitive and informative, because it has more pet items, and it can detect the parts with high glucose metabolism in the whole body through glucose-labeled FDG, which are often tumor lesions for tumor patients. Therefore, PET-CT is a functional examination.
There are two types of patients who need extra attention when doing PET-CT: diabetic patients with poor blood sugar control are not suitable; Patients with claustrophobia are not suitable, because PET-CT examination needs to scan in a narrow space for about 2 minutes.
Other precautions for PET-CT:
1. Stop taking all unnecessary drugs and aminophylline and other vasodilators 4-6 hours before the examination (please follow the doctor's advice in special cases).
2. those who have had barium meal examination or barium enema within 7 days before the examination need to be cleared of barium in the intestine before they can be examined.
3. Patients with chronic diseases: If you take drugs to control chronic diseases for a long time, please take them with you on the day of examination. Please follow the doctor's advice on the time and method of taking drugs orally.
4. Diabetic patients: (1) Please consult a doctor before the examination to determine the fasting schedule, the usage of oral hypoglycemic drugs or insulin; (2) Take hypoglycemic drugs with you during the examination, and actively inform doctors and nurses of the types, dosages and usage of hypoglycemic drugs currently being used.