How to reduce radiation in CT examination
Every time we go to the CT room, there is always a trace of uneasiness in our hearts, just like meeting each other’s parents for the first time. If the baby wants to take photos, parents will be even more frightened.
What is CT?
Let’s put it this way. X-rays flatten people. Ultrasound is like knocking before picking watermelon. MRI is shaking and looking again. And CT, great, cut people into pieces and look at them carefully. And the slice thickness is < 1 mm. So, how does CT work? The CT imaging process is very complex and professional. I’m afraid you don’t understand it. Simply put, the machine sends out X-rays, penetrates the human body and reaches the processor to form an image.
CT has two ways
Ordinary plain scan: just lie on the CT machine and complete the scan in a few seconds;Enhanced scanning: on the basis of plain CT, iodine contrast agent is injected intravenously. Iodine contrast agent will run to the tissues and organs of the whole body with the blood circulation.
After playing iodine contrast agent, you can observe the condition of diseased tissue and compare it with surrounding normal tissue to see if there is any lesion. In a word, enhanced scanning can see more and more clearly. For patients who come to see a doctor for the first time, the doctor does not know what the condition is, and may ask them to do an ordinary CT examination first.
If ordinary CT can see the lesion and make a definite diagnosis, there is no need for enhanced CT. However, if ordinary CT can not see very clearly, or the results are not sure of the diagnosis, enhanced CT is needed. It should be reminded that few people will have different degrees of adverse reactions to the iodine contrast agent injected by enhanced scanning. Therefore, please read the iodine contrast enhancement consent carefully. Drink plenty of water before and after enhancement. The iodine contrast agent will be discharged with urine, and it will be completely emptied in 24 hours.
No, don’t panic. Since the X-ray emitted by the machine penetrates the human body, will it do great harm to the human body? The harm of CT mainly comes from ionizing radiation produced by X-ray. Ionizing radiation can destroy some macromolecular structures in the human body, damage cells, and thus damage the human body. In fact, there is no need to do CT. There is radiation in many things in life. Just ask if you panic?
Dose of 0.1 mSv for 20 hours by plane; 20 cigarettes per day, 0.5-2 mSv per year; Subway security passengers may receive a dose of < 0.01 mSv per year; The natural background (background) radiation dose received by each person every year is about 2 mSv.
So, do a CT, what is the probability of cancer?
From animal experiments, unless exposed to long-term and high-dose irradiation, the probability of canceration and bone marrow suppression is very low. How to explain that Madame Curie died of aplastic anemia (bone marrow suppression)? That’s because she deals with radioactive materials all day. Long-term and large-scale exposure to radioactive materials is equivalent to taking CT all the time. So, don’t panic when it comes to radiation. Just count the CT you do. You know it’s safe.
What tests are CT used for
Some people may ask, now that the technology is so developed, since CT has more or less radiation, why not just Ko it? This is really impossible. Under the guidance of doctors, the amount of CT radiation is within the safe range, and CT has a wide range of applications. It has unparalleled advantages in the examination of the head, lungs, limbs and other parts——
Maxillofacial and neck: maxillofacial tumors, fractures, inflammation, etc., such as orbital lesions, sinus cancer, nasopharyngeal carcinoma, middle ear mastoid lesions, thyroid diseases, neck masses, etc;
Head:Cerebral trauma, cerebral hemorrhage, cerebral infarction, vascular malformation, brain tumor, abnormal brain development, etc. CT is the first choice for the diagnosis of acute cerebral infarction, cerebral hemorrhage and craniocerebral trauma;
Chest: various tumors, tuberculosis, inflammation, bronchiectasis, pulmonary abscess, atelectasis, pneumothorax, fracture, esophageal foreign body and various variations of lung, pleura and mediastinum;
Abdomen and pelvis: it is mainly used for the diagnosis of liver, gallbladder, pancreas, spleen, peritoneal cavity and retroperitoneal space, as well as the diseases of urinary and reproductive system, and the display of the location and causes of intestinal obstruction. It has important reference value for the display of gastric cancer, colon cancer and its invasion of extraluminal structures and distant metastases;
Skeletal system: skull and spine micro fractures, intervertebral disc lesions, spinal canal stenosis, bone tumors, bone tuberculosis and inflammation, and can carry out three-dimensional imaging and multi-sided imaging of the diseased parts.
Is there any way to reduce radiation?
During CT, you can shorten the contact time as much as possible – remove metal objects
Before entering the CT room, the doctor will prompt to remove metal objects. Some women even need to take off their underwear. What do you think? Let you take it off, just because during the examination, do not let metal objects interfere with the examination results, form a shadow, and affect the correct judgment of the doctor;
Make preparations for the examination in advance: during the CT examination of the stomach, it is recommended to drink more water to fill the stomach and improve the examination effect;
Cooperate with the doctor to shorten the examination time: during CT examination, the doctor will put forward some requirements and require the patient’s cooperation, such as prompting the need to inhale and hold breath.
Of course, CT is essentially an X-ray machine, which has higher requirements in terms of radiation protection. Unless special needs, repeated unnecessary review is not allowed. After inspection, we can reduce the impact of radiation by drinking green tea, eating more fresh vegetables and fruits, such as carrots, oranges, tomatoes and apples, as well as kelp, laver, black fungus and other anti radiation foods.
Pregnant women had better not do CT before 12 weeks, and then it will be determined according to their condition; Babies need to choose low-dose CT scanning; Patients with hyperthyroidism should choose enhanced CT scan carefully.