People usually have four misunderstandings about taking
X-rays: they believe that radiation is harmful to the human body and insist on not taking X-rays even if they are sick; metal is not in the way; both sides of the human body must be taken; and the effect of taking pictures while standing or lying down is Same. The doctor reminded that taking X-rays is the most common imaging examination, and there is no need to misunderstand it.
Misunderstanding 1: Radiation is harmful to the human body, so we insist on not taking X-rays even when we are sick.
According to doctors, the X-ray dose received during an upright chest radiograph is 0.12 mSv, which is about 1/20,000 of the maximum single dose that can cause damage to the human body. Therefore, an ordinary The degree of harm is not great, so there is no need to worry too much. "People often say that medicines have three types of poisons. Any medicine has adverse reactions and toxic side effects, but as long as the medicine is used correctly and its dosage is mastered, the medicine can exert its maximum effect and serve patients." The doctor gave an example, such as You can get vitamin D from basking in the sun, but too much exposure to the sun can cause skin cancer. In addition, there are also many electrical appliances in our lives that emit radiation. Should we just abandon them? The key is how to use it.
Misunderstanding 2: It doesn’t matter if it’s not metal
With the continuous improvement of popular culture and medical knowledge, people gradually realize that metal and high-density items can hinder the penetration of X-rays, such as metal buttons, necklaces, jade pendants, bras, etc. Patients generally cooperate with doctors to remove them, but Paint patterns on knee pads, plasters, quilts, and clothes will all affect the penetration of X-rays and even leave images on X-rays, making it difficult for doctors to make a diagnosis. For example, Ms. Wang, a patient, took an X-ray with her baby who had a cold and fever. She was worried that taking off the sweater would aggravate the baby's cold. Ms. Wang refused to take off the baby's clothes no matter what. The child's chest X-ray, which was already difficult to diagnose, had a lot of artifacts due to the interference of a few sweaters, so it had to be re-taken.
Misunderstanding 3: Both sides of the human body must be photographed
If the camera we usually use takes pictures of the left side of the face, it cannot see the right side. But X-ray is different. It is penetrating and can clearly see the substantive content inside. Therefore, if the limb bones and spine are photographed in a lateral position, it will be fine. It's not like the lungs are divided into left and right lungs, so once there is a problem on either side, the X-ray film needs to be placed on that side. The purpose is to make the diseased side more clearly displayed on the X-ray film to reduce magnification. For example, Mr. Li accidentally fell and injured the right side of his calf. When he went to the hospital to take a picture, the doctor only took one side view. Mr. Li thought that the other side was not taken and insisted on taking a picture of the other side.
Misunderstanding 4: Shooting while standing has the same effect as shooting while lying down
There is no difference in the effect of shooting while standing and shooting while lying down. This is a misunderstanding. Take chest photos as an example. The purpose of taking photos standing up is to make the heart shadow natural under the action of gravity, and to expand the lungs when inhaling. The chest photo can reduce the blurring of the heart and reduce the magnification rate of the heart. Due to the increase in projection distance, the shoulder blades on both sides are projected outside the lung field and the magnification rate of the chest is reduced. This effect cannot be achieved when shooting while lying down. Therefore, when it is time to stand for the photoshoot, the patient should insist on standing or sitting even with the support of relatives and friends. Of course, flexibility is necessary when life is at stake.
7 things to know about radiology examinations
1. Go on an empty stomach
You cannot eat or drink before some medical imaging examinations, such as upper gastrointestinal barium meal examinations, PET/CT, and DSA examinations. In addition, patients with suspected intestinal obstruction, intestinal perforation, acute pancreatitis, and those undergoing CT angiography or suspected of having stones should not eat or drink before the examination. Some patients not only cannot eat before the examination, but also drink laxatives or take an enema from the anus to empty the intestines of feces. This is called intestinal preparation to avoid affecting the diagnosis of urinary system stones or the effect of barium enema. . When taking plain abdominal X-rays, bowel preparation must also be performed when there is gas in the intestinal cavity that affects the diagnosis or when fecal stones are suspected.
2. Remove foreign matter
When you plan to go to the medical imaging department for medical imaging examination, the first thing you have to do is to remove all foreign objects in the imaging area to prevent foreign object artifacts from hindering imaging diagnosis. For example, before you do a chest X-ray, you need to remove necklaces, jade pendants, buttons, zippers, bras, and even clothes with painted words and paintings on them. Likewise, remove necklaces, buttons, and belts when photographing the pelvis. If it is an MRI examination, these metal foreign objects can not only seriously affect the image quality, but also generate a certain amount of heat and burn your skin during the examination. Therefore, it is best to wear cotton clothing when doing medical imaging tests. It is better to wear white clothes, avoid black or dark gray, so that the doctor can take pictures of the center line for you.
3. Cooperate with the doctor
When taking a chest X-ray, the doctor will give instructions to inhale and hold your breath, and you must follow them. The purpose of inhaling is to fill the lungs with air to create good contrast, and to hold the breath is to avoid movement blur artifacts caused by breathing movements. Breath-holding during CT and MRI examinations of the chest and abdomen is not only to reduce motion blur artifacts, but also to avoid changes in the scanning level caused by irregular breathing, which may lead to missed lesions. Therefore, during the examination, you must follow the doctor's instructions and perform relevant actions.
4. Eat and drink enough
In addition, there are also some medical imaging tests that require eating and drinking. For example, for CT examination of the abdomen, the amount and time of drinking water are very particular. During upper abdominal CT examination, you have to drink 300 ml of diluted contrast agent, and the examination can be carried out shortly after drinking. When performing a CT examination of the kidneys, the total amount of water drunk in batches reaches 800 ml, and it takes 20 minutes to wait for the examination. When doing prostate, bladder and gynecological ultrasound examinations, you also need to drink plenty of water and make sure your bladder is full before conducting the examination.
5. Pay attention to the order
It is precisely because some examinations require eating and drinking, while other examinations require fasting, so there is a sequence when doing these medical imaging examinations at the same time. Usually, examinations that do not require eating, drinking, or injections can be performed first, while examinations that require eating, drinking, or even injections must be performed later. Otherwise, once the order of inspections is reversed, and the inspections that should be done later are done first, then the inspections that should be done earlier will have to wait a week.
6. Follow-up work
After the medical imaging examination is completed, you are not done. You still have a lot of aftermath work to do. For example, when you have been injected with contrast agent for X-ray imaging or enhanced CT scan and contrast imaging during the examination, you must rest in the lounge for 15 minutes before leaving the medical imaging department to prevent the occurrence of allergic reactions. After returning home, you need to change clothes, take a shower, and remove radioactive contamination. Another point is to drink more tea to promote metabolism and excretion.
7. Remember the taboos
Indiscriminate medical imaging examinations can also cause adverse consequences, even death. Therefore, you should keep in mind the contraindications associated with medical imaging tests. More importantly, you should truthfully report your situation to the doctor, such as whether you have a history of allergies, including allergies to penicillin or allergies to foods with high iodine content such as kelp. This will tell the doctor whether he or she can perform an imaging test on you. If you have a pacemaker or have shrapnel, metal implants, insulin pumps, etc. in your body, these are contraindications for magnetic resonance imaging.
