CT scans use ionizing radiation to create transverse body images, providing more details than X -rays.
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Computed tomography diagnose the afflictions of tumors with kidney stones at potentially deadly diseases and injuries, such as aneurysms and blood clots leading to a stroke.
But the radiation issued by this essential diagnostic tool can cause more harm than that before and could possibly be responsible for around 5% of all cancers diagnosed in the United States in a single year, A new study finds.
“Medical imagery has potential advantages,” said the radiologist Dr Rebecca Smith-BindmanProfessor of epidemiology at the University of California in San Francisco, and principal author of the study published Monday Jama internal medicine. “It also has potential damage, and it is really important to balance them.”
A long time ago, scientists have established that the ionizing radiation issued by computed tomographyor CT scan, analyzes increase the risk of cancer. However, since 2007, the use of imaging technique has increased by 35%, according to the study, partly due to the growth of what Smith-Bindman and his colleagues call “a low-value image, potentially useless”.
Their new research, based on the projections of hospitals of 20 American states, estimate that 103,000 cancer diagnoses, or 5% of all cancers, could result from 93 million scans carried out in the United States in 2023 only.
“There is nothing that you can do about the radiation you have already been exposed. But you want to limit future exposure to cases when you really need it,” said Smith-Bindman.
Some analyzes may add any diagnostic value, she said. In addition, the quantity of radiation that a scan emits fluctuates largely and can be much higher than necessary with the operator, not the machine, making the difference, she said. The dose in a scanning installation can be 50 times stronger than another.
Dr. Dana Smetherman, chief executive officer of the American College of Radiologists, praised the study to raise awareness of the question of the risk of radiation. Some people are unaware, for example, that ultrasounds and MRIs do not emit radiation and that computed tomography is, she said.
“As radiologists, we always want patients to be informed and feel comfortable asking the questions:” Tell me more about this test, what is involved, what will you show you? “” Said Smetherman, who was not involved in research.
Resonate a declaration From the American College of Radiology after the release of the study, she stressed that the projection of the study of cancer diagnostics from computed tomography was based on statistical modeling, and not on the real results of patients.
There are no published studies directly linking CT scans to cancer, the declaration indicates. “Americans should not give up the necessary and vital medical imaging and continue to discuss the advantages and risks of these exams with their health care providers,” he continues.
Computed tomography use ionizing radiation to create transverse images inside the body. Analyzes can reveal more details than conventional X -rays and are precise, fast and relatively inexpensive.
At the national level, new CT cancer projections put them on equal with other well -known risk factors at the scale of cancer population, such as alcohol and obesity, Publisher’s note The support of the study underlines the study. Smoking remains the main contributor to American cancers, causing 19%, followed by excess body weight at 7.6%and 5%alcohol consumption, Smith-Bindman said.
To reduce exposure to radiation, study authors and editorial changes to changes in current practices.
The safest way to eliminate exposure to the radiation from computed tomography is to stop making those of low value. However, efforts to restrict them, including an initiative by the American Board of Internal Medicine Foundation called Choose wisely This was launched in 2012, said Smith-Bindman said.
She thinks that the greatest opportunity to reduce the risk of computed tomography is to optimize the dose used in each scan.
“We can absolutely try to reduce all of these excessive doses,” she said. “We need the membership of doctors and hospitals.”
She says that patients can try to reduce their risk of cancer by chatting with their doctors how important it is to obtain a particular analysis and how they could Receive such a small dose of radiation from a scan if necessary.
The University of California in San Francisco, is organizing a website called Know your dose In an effort to allow patients to ask questions about the amount of radiation they receive from analyzes.
A brain analysis, according to the website, can issue as little radiation as 200 dental x -rays or up to 1,600. The dose of radiation from an abdominal scan for a suspected renal stone can be as low as 100 dental x -rays or up to 8,000. Renal calculations can also sometimes be diagnosed with ultrasounds, which do not issue the website.
One of the reasons for striking differences in radiation emissions is that sometimes patients are scanned only once, and other times they are scanned several times. Several images are often useless, said Smith-Bindman.
Although they and others have been Press federal standards For doses, there is none.
Under one Health insurance measurement tool Released in January, hospitals and imaging facilities share information on the quantity of influence that their scanners emit. Based on the information, Smith-Bindman and his colleagues develop a quality measure for computed tomography. So far, she said, a third of the scans exceed the objectives of their tests.
“We need patients to ask their doctors:” Can you use a low dose when you scan me? “” Smith-Bindman said. “It’s crazy that patients have to ask for it, but it’s really really successful.”
Ronnie Cohen is an independent writer in the San Francisco Bay region.