Recent Survey Highlights Dangers of CT Scan Overuse

A recent survey released by Consumer Reports suggests that Americans may be subject to the overuse of CT scans, potentially increasing the risk of various types of cancers.

Computed tomography (CT) scans are imaging tests used for diagnostic purposes, such as when an infection or tumor is suspected. Doctors can use CT scans to evaluate blood vessels, muscles, bones, and more. The technology uses x-rays to create pictures. However, CT scans use a great deal more radiation than do x-rays.

Studies substantiate concerns

One study by researchers from UC San Francisco determined that one typical chest CT scan is the equivalent of approximately 100 x-rays of the chest. These figures can fluctuate widely, depending on the hospital, the scanner, and the doctor. In some cases, CT scans can use the equivalent amount of radiation as 440 x-rays. The sheer dosage of radiation combined with the potential for one patient to undergo many CT scans over a lifetime has healthcare advocates concerned about the link to cancer development.

As Consumer Reports notes, the use of CT scans in the U.S. has climbed at a quick pace. Currently, doctors order about 85 million scans each year, a three-fold increase since 1993. Researchers assessing the dangers of CT scan overuse determined that with the number of scans performed in 2007 alone, 29,000 diagnoses of cancer could result. This study was published in the Archives of Internal Medicine.

In many cases, CT scans do provide valuable information for doctors and patients. However, a growing body of research suggests that doctors do not need to set the radiation dosage on the scanners as high as they typically are. A 2009 study published in the Archives of Internal Medicine evaluated scans conducted at hospitals in the San Francisco area. It determined that the average radiation dose used for scans of the abdomen and pelvic regions was 66 percent higher than needed.

Radiation exposure in the hospital is particularly troubling for a certain demographic: children. The youngest of patients are especially vulnerable to the effects of radiation and are at a higher risk of developing cancer. However, researchers have found that children are often exposed to the same high dosage of radiation that adults are exposed to.

Hospital ratings reflect worrisome trend

The dosage of radiation isn’t the only concern expressed by researchers. Often, doctors are in the habit of ordering “double scans.” That is, they’ll order a traditional CT scan of a body part such as the abdomen. Afterward, they may order a second CT scan of the same body part with the use of contrast dye to provide a better image. Researchers suggest that this practice isn’t necessary in most cases and unnecessarily exposes patients to additional radiation within a short period of time. In fact, in only about one percent of cases are double scans found to be useful.

Consumer Reports has compiled hospital ratings to reflect which institutions are in the practice of frequently ordering double scans. They considered a double scan incidence rate of five percent or less as ideal and only 30 percent of hospitals surveyed made the cut-off. When doctors do order double scans, the most common body part scanned is the abdomen, followed by the chest.

Reduucing hospital radiation exposure

Patients can act as their own advocates to guard against the potential dangers of the overuse of CT scans. They can question the doctor about what the potential benefits of the CT scan are versus the potential drawbacks. In addition to asking whether the scan is strictly necessary, they can discuss the dosage of radiation and whether it could be lower. It may be possible to prevent a double scan by inquiring about undergoing a scan with contrast dye first. Additionally, getting a second opinion from a different doctor is always an option for patients.