How often should lung CT be done?
On this issue, everyone is more concerned about two points:
The first point is the radiation angle. Is there any radiation hazard if you do too many lung CT scans?
The second point is the discovery of lung cancer. How often can lung CT be done to help us detect early-stage lung cancer earlier?
Next, I will talk to you about lung CT from the above two points. Let’s look at the first point first, about lung CT radiation.
First of all, let’s talk about whether there is any radiation in lung CT? I think everyone knows this. As long as a lung CT is taken, there will be radiation.
Why?
You may have no objection to X-rays and chest X-rays containing radiation. But some people still don’t know much about lung CT.
In fact, the radiation source of CT is also X-ray!
So we say that this is also irradiated with X-rays. Why are there two types of examinations, X-rays and CT? Sometimes even after some patients take a chest X-ray, we will ask them to take another one. CT?
Why is this?
Actually, this is the difference between X-ray and CT. You can understand it this way, we think of our chest as a piece of bread. When we take X-rays, we actually flatten the piece of bread on the chest into a whole piece;
But CT is different. It is like using a knife to cut the "bread" on our chest layer by layer, into many "pieces", and look at them in layers.
Obviously, CT can see more clearly, because it does not overlap. It shows us a cross-sectional image, layer by layer, allowing us to see more clearly and densely. The resolution is higher, which is ten times higher than our chest X-ray. Therefore, CT can display the detailed information of our lesions more completely and thoroughly.
So, sometimes the reason why our doctors ask patients to take CT scans after taking chest X-rays is because sometimes we find problems or suspect problems after taking chest X-rays, but we can’t 100% % Confirmed and confirmed, a clearer CT will be chosen at this time.
Why not just go to CT?
First, CT is more expensive than X-rays;
Second, some diseases can be diagnosed by taking X-rays, so there is no need to over-treat;
Third, from the perspective of radiation, if you think about it, taking a CT scan is equivalent to taking several X-rays. Naturally, the radiation from one CT scan is stronger than one X-ray scan!
According to this, CT radiation is relatively strong, how often should a person do it?
First of all, when we say that CT radiation is relatively strong, it is for X-rays. Taking one CT is equivalent to taking 300 chest X-rays, but this does not mean that there is no limit to our CT radiation dose!
For example, our country now requires that a chest X-ray be taken at 0.3 mGy. Generally, for a CT scan, the dose is 8 mGy, but this is not necessarily the case. It depends on the location where you take the shot and the specific lesions.
Now our CT machines have made great progress and can control the shooting dose through mA automatic dose control.
For example, in some parts, it is thicker, so we have to increase the dose, and the radiation will definitely be larger. For example, if there is air in our lungs, where there is a lot of air, it will penetrate more easily, and it will automatically reduce a little, and pass through. This technology, in fact, our CT examination is not as scary as everyone thinks. After using this technology, the dose has been greatly reduced. Basically, one shot is 4-5mGy!
How often should it be done?
Although CT radiation has been reduced a lot, after all, one shot is still equivalent to 100 chest X-rays. Therefore, from a health perspective, we recommend that CT examinations be used scientifically!
For example, if it is purely for physical examination, then we say that once a year is enough, but if you find that there is a problem, then you can take it twice a year;
But if you say If you really need to diagnose and treat the disease, then it is wrong for us to stick to the principle of CT radiation hazards and CT taking once a year. At this time, we have to weigh the pros and cons, because there are many diseases that are not ours. It is enough to take one or two pictures to see if there are any changes. We must conduct dynamic observation to see if there are any changes. For example, for the most common pulmonary nodules, we need to follow them up regularly. Sometimes we may need to take pictures several times a year. Times, this is actually possible! And for the cancer patients we are talking about, undergoing chemotherapy, they may need to be photographed every other month!
So, from a radiation perspective, how often a lung CT scan is better must be determined based on the purpose of your examination and the needs for disease diagnosis and treatment. There is no guarantee that it must be one year. Once or no more than twice a year is better! Next, let’s look at the second point. From the perspective of detecting lung cancer, we say how often lung CT can help us detect early-stage lung cancer earlier?
First of all, let’s talk about whether lung CT can detect lung cancer? What kind of results should we pay attention to, which may be lung cancer?
The answer is definitely yes! As I mentioned above, lung CT has two advantages: one is that there is no overlap in the images and it is a layered display; the other is that the density resolution is high. Therefore, basically all lung lesions can be seen, including inflammation, tuberculosis, and other lesions, including tumors. It’s just that it cannot diagnose lung cancer. The diagnosis requires further examination and biopsy!
What kind of results should we pay attention to, may it be lung cancer?
As we all know, tumors are basically a nodule or a spherical shadow. This is a relatively common outline. Then we need to look at the specific shape, that is, whether the nodule will look like this. Burr
or such a lobulation sign
or whether there will be pleural traction sign
or such a bronchial sign, etc.
These are actually relatively common malignant characteristics of nodules. The more there are, the higher the degree of malignancy, and the greater the possibility of lung cancer!
How often is better to take photos?
As I said before, it depends on the specific situation. The most important thing is based on the results of your last X-ray. Therefore, you must keep the CT X-rays you usually take and bring them with you every time you go to the doctor. Only through comparison can we doctors make better judgments!
If you just go for a physical examination and take a lung CT for the first time to see if there is lung cancer, then if the results are normal, then just check it once a year!
But if you say you have found pulmonary nodules, we are not saying that as soon as we see a patient with pulmonary nodules, we recommend that he have a CT scan once a month. It is scientific to do such intensive examinations. guide.
For example, if your pulmonary nodule is just a nodule less than 6mm, you don’t need to worry too much. Just check it once a year or start taking pictures every six months. If there is still no change, change it to one year. Just take a look at it during the physical examination!
But if you are a high-risk group for lung cancer, it is recommended to have a reexamination every 3-6 months.
Then based on the results, a professional doctor will tell you whether you need to continue re-examination in the future and how often you need to take pictures. This requires professional advice, not just what you want!
In summary, for early screening of lung cancer through CT, it must be a process of taking a film, discovering problems, reexamining, and then judging based on the reexamination results, and then deciding how often to take another scan. Individual follow-up schedules are different, because nodules are likely to be different. Some people may be solid, some may be subsolid, and some may be ground glass, and they must be treated differently.
At the same time, it does not mean that re-examination is okay. All nodules do not need to be treated. Like some high-risk nodules just mentioned above, sometimes even though there is no change, we sometimes do it to prevent accidents. After doing some evaluation, I made a relatively aggressive surgical decision to cut it out!
Everyone must remember that there are two doors that can block lung cancer: one is to quit smoking; the other is our lung CT screening!
If you still have any questions about lung CT and lung cancer, you can leave a message below. I insist on using words that everyone can understand and the most original coding method to bring you the best and most comprehensive , the most practical health science popularization. If you think it’s good, you can follow “Medical Detective” and forward it to benefit more people around you!