Complications of a CT scan The CT scan is a very safe procedure. Some people who have an injection of
CT scans use X-rays, which produce ionizing radiation. Research shows that this kind of radiation may damage your DNA and lead to cancer. But the risk is still very small -- your chances of developing a fatal cancer because of a CT scan are about 1 in 2,000. But radiation's effect adds up over your lifetime.
The amount of radiation is greater than you would get during a plain X-ray because the CT scan gathers more-detailed information. The low doses of radiation used in CT scans have not been shown to cause long-term harm, although at much higher doses, there may be a small increase in your potential risk of cancer.
Risks of CT Scan
Radiation exposure during pregnancy may lead to birth defects. If contrast dye is used, there is a risk for allergic reaction to the dye.
There is no recommended limit on how many computed tomography (CT) scans you can have. CT scans provide critical information.
Does any radiation stay in the body after an imaging exam? After a radiographic, fluoroscopic, CT, ultrasound, or MRI exam, no radiation remains in your body. For nuclear medicine imaging, a small amount of radiation can stay in the body for a short time.
Since the test uses quite strong radiations, people often worry about the risk of developing cancer from it. While there are things to be aware of, the risk of radiation exposure related cancer is quite low. CT scans are generally worth the risks associated with radiation exposure due to its multiple benefits.
The effective doses from diagnostic CT procedures are typically estimated to be in the range of 1 to 10 mSv. This range is not much less than the lowest doses of 5 to 20 mSv received by some of the Japanese survivors of the atomic bombs.
Newer scanners will adjust the radiation exposure automatically and reduce the exposure. Repeated CT scans should be avoided, and certainly if the scans are being repeated only because the physician does not have access to the images from a recent CT scan.
The typical CT radiation dose is 10 to 20 millisieverts (mSv), which is associated with a lifetime risk of fatal cancer of approximately one per 2,000 CT scans.
Delayed adverse reactions to radiographic contrast media are usually cutaneous (reported incidence varies from 1% to 23%) and include rash, skin redness, and skin swelling, sometimes associated with nausea, vomiting, and dizziness, that begin 1 hour or longer (usually 6–12 hours) after the administration of the ...
The U.S. Food and Drug Administration estimates that the extra risk of any one person developing a fatal cancer from a typical CT procedure is about 1 in 2,000. MRIs do not use ionizing radiation, so there is no issue of raising cancer risk. But they take much longer to complete than CTs.
Drinking fluids not only replenish your body but also helps flush out the contrast dye if you received a CT with contrast. The contrast dye used with a CT is not harmful.
When the CT scan is over, you can resume normal activities. If you had intravenous contrast, you should drink at least eight glasses of water throughout the day to help flush the contrast out of your body. Your doctor will receive the results within 48 hours.
Unlike X-rays and CT scans, MRIs don't use any radiation. At Johns Hopkins, we've developed very fast, high-resolution MRIs that can be done in 10 minutes or less. An MRI scanner is a highly specialized machine and may not be available in some imaging facilities or emergency rooms at other hospitals.
CT scans generally involve higher radiation doses than other imaging tests. The radiation exposure can range from 2 to 10 millisieverts (mSv) per dose, depending on the type of CT scan and the body part being imaged. Some complex CT scans or repeated scans may result in higher radiation exposure.
After the Procedure
Otherwise, there is no special type of care required after a CT scan of the chest. You may resume your usual diet and activities unless your physician advises you differently.
Chronic back pain or an injury to the spine are among the most common reasons to have a CT scan. A doctor may also order a spinal CT scan to: Evaluate spinal fractures. Assess the condition of the spine before and after surgical procedures.
It uses powerful X-rays, a form of radiation, to create detailed pictures of the inside of your body. Some people worry about getting this test because radiation is known as a possible cause of cancer. Know that the chances of getting cancer from a CT scan are very low.
That can help them identify tumors, bleeding, blood clots, infection, fractures, and many other problems. You may need a CT scan if you are having unexplained dizziness or headaches. You may also need one if you recently suffered from a stroke or blow to the head.
CT scans are far quieter and do not cause hearing problems compared with MRIs. CT scans are also preferable among those who are claustrophobic or anxious because the machine is more open and the X-ray device circles around the patient. The main disadvantage to having a CT scan is that it exposes your body to radiation.
Wash your hands, face, and parts of your body that were uncovered at a sink or faucet. Use soap and plenty of water. If you do not have access to a sink or faucet, use a moist wipe, clean wet cloth, or a damp paper towel to wipe the parts of your body that were uncovered. Pay special attention to your hands and face.
After the scans, the research did show an increase in DNA damage in cells, as well as cell death. There was also increased expression of genes involved in the repair or death of cells, the study found. Most cells damaged by the CT scan were repaired, the researchers said, but a small percentage of them died.