Doctor’s Tip: Do you really need that CT scan?
The University of California, Berkeley’s July Wellness Letter contained an important article: “Should You Worry About CT Scans?”
X-rays were invented some 120 years ago, and they clearly improved doctors’ diagnostic capability. CT scans were invented in the 1970s, and improved diagnostic capability considerably more. I can’t imagine practicing medicine in the days before X-rays, but was in training in the 1960s and early 1970s, before CTs, which were a boon to both patients and doctors.
However, there are downsides to this technology, the most serious one being radiation exposure, cost being another. Soon after X-rays were in common use, they were found to cause hair loss and burns in patients and in personnel who performed them. In spite of that, X-rays were used for conditions such as enlarged tonsils.
Those of us my age (75) recall going to a Buster Brown shoe store and putting our feet in a fluoroscopic X-ray machine to determine shoe fit. After decades, the seriousness of radiation exposure became apparent, and protection was offered to patients, doctors and techs. We now know that radiation causes dangerous free radicals and cancer-causing DNA damage.
CT stands for computed tomography. These scans create several cross-sectional images, and involve many times more radiation than simple X-rays. CT scans are used to diagnose conditions such as heart disease, cancer, the cause of abdominal and pelvic pain, kidney stones and injuries.
According to the Berkeley article, “CT scans of the abdomen and pelvis tend to produce the most radiation, averaging 100 to 200 times more than a simple chest X-ray, 1,500 times more than dental X-rays, and 200,000 times more than airport scanners.” Other types of imaging that utilize high levels of radiation include nuclear cardiac stress tests, fluoroscopy and PET scans.
Radiation is cumulative over a lifetime, and is particularly damaging to infants and children, even more so in the fetus. Radiation from diagnostic studies is thought to cause about 2 percent of new cancer cases in the U.S. A paper published in a respected medical journal in 2009 claimed that CT scans done in 2007 were projected to cause 29,000 extra cases of cancer and eventually 14,500 deaths. Unfortunately, Americans are exposed to at least six times more radiation from medical imaging (mostly CT) than we were three decades ago. According to the Berkeley Wellness Letter, it’s thought that a third to half of CT scans may be unnecessary.
According to Consumer Reports, here are the factors that contribute to overuse of CT scans:
• Financial incentives: We have a health-care system that rewards providers for ordering lots of tests. Some physicians and most hospitals own radiology equipment or diagnostic centers, and when CT is easily available, it’s used.
• Fear of lawsuits, which may account for 35 percent of diagnostic imaging.
•Physicians who don’t understand the amount of radiation CT scans cause, the dangers associated with that radiation or that other types of radiation-free imaging such as ultrasound and MRI may be just as adequate.
• Misinformed patients: Fewer than one in six patients in a Consumer Reports survey said their doctors had warned them about radiation risks or that there were safer alternatives.
• Patient demand: Many patients insist on an X-ray or CT scan.
• Lack of regulation: Unlike mammography, there are no federal radiation limits or universal standards for CT imaging.
What can you do? Here’s what Consumer Reports and the Berkeley Wellness Letter recommend:
• Ask if the CT scan is really necessary, will improve your health and if a radiation-free alternative is an option.
• Check credentials for the imaging facility and the tech.
• Get the right dose for your size. The smaller and thinner you are, the lower the radiation dose you need. Children require much smaller doses, but according to Consumer Reports they are often given adult doses.
• Ask for the lowest effective dose, make sure the scan is limited to the body part in question and that adjacent areas are shielded. The radiation dose of a CT scan can vary even within the same hospital, and a 2013 JAMA Pediatrics study claimed that cutting the highest doses could cut in half the number of future radiation-related cancers.
• If the recommended CT scan is a repeat of a previous one you’ve had, ask why it needs to be repeated.
• Ask your doctor if the facility has a financial interest in the CT scanner, and if so, get a second opinion.
• Avoid total body scans, which often result in what doctors call “incidentalomas.” A scan shows a small shadow, which is almost always an incidental finding of no significance, but to be 100 percent certain instead of 99.9 percent, additional imaging or even biopsies are ordered.
• Avoid cone-beam CT dental X-rays, especially in children.
Remember that in many cases, CT scans are appropriate and necessary and can be lifesaving. But they should be used with caution, and your provider is obligated to discuss the pros and cons and alternative options. If you do need a scan but will have a large out-of-pocket expense, check prices at different facilities including Grand Junction (both St. Mary’s and Community Hospital) and Denver.
Dr. Feinsinger, who retired from Glenwood Medical Associates after 42 years as a family physician, now has a nonprofit Center For Prevention and Treatment of Disease Through Nutrition. He is available for free consultations about heart attack prevention and any other medical concerns. Call 970-379-5718 for an appointment. For questions about his columns, email him at firstname.lastname@example.org.
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