CT SCANNING

By admin
March 07, 2012

As an informed consumer, what you should know about medical radiation.

by Mary Meek

There is no question that the advent of CT (computed axial tomography) technology has revolutionized the way physicians are able to diagnose illness and injury. Where once invasive, exploratory surgery was often the only way to determine what is happening to a patient internally, CT scans have made it possible to examine soft tissue structures and bones inside the body, quickly, painlessly and with ever improving clarity. No doubt countless thousands of lives are saved each year because the technology is available, especially in the emergency room. In fact, between 1996 and 2007 (according to a review of hospital data) the use of CT scans in the emergency room increased 330 percent.

What is a CT Scan?
So the explosion in the use of diagnostic CT scans is a win-win situation – right? Not so fast. Before we tout CT technology the best thing since penicillin, we need to look at how CTs work. CT scans use iodizing radiation generated from a source that is rotated around the body to create 3 dimensional images of the internal organs and bones. While radiation also is used for a standard X-ray, the degree of radiation exposure from a CT scan is much greater, an estimated 100 – 800 times that of a chest X-ray. Since iodizing radiation is a known carcinogen, it is important to limit exposure whenever possible.

While one CT scan is not going to cause you to develop cancer, over time radiation exposure can build up. Over a lifetime, especially for children who undergo repeated CT scans, the cumulative effect can be serious. That is why it’s crucial for us to know the facts and be aware of both the considerable benefits of CT technology and of the potential dangers.

Not all radiation exposure is equal.
We are all exposed to small amounts of radiation daily from soil, rocks, building materials, air, water, and even from the sun. This is called background radiation. To determine the degree of radiation we receive from medical tests it is compared to the amount we receive daily from background radiation. Because different tissues and organs have varying sensitivity to radiation exposure, the actual radiation risk to various parts of the body from an X-ray or CT procedure varies. The chart below gives some examples of the differences in radiation exposure by type of procedure and body part. The range is striking, when compared to a day of naturally occurring background radiation.

Pros
We know that CT scans give doctors a glimpse into what is going on inside the body that was not possible before the technology was developed, often allowing physicians to treat their patients more effectively, and ultimately saving lives. We also know that studies have shown that the increase in the use of CT scans in emergency rooms actually has helped to reduce the number of patients admitted to the hospital unnecessarily.

Cons
There is no doubt that long-term over-exposure to iodizing radiation can be dangerous. With CT scanning, as with any new technology, there is potential for harm if stringent guidelines are not followed when it comes to the application, intensity and frequency of use. Overuse of CT scanning can also drive up costs to the healthcare system. In 2008, The New York Times reported that over 150,000 CT scans were conducted.

How the FDA is working to make imaging safer.
To address these concerns, in February of last year, the FDA announced the formation of a cooperative with the purpose of reducing unnecessary radiation exposure. Through this initiative the FDA and its partners hope to:

  • Promote safe use of medical imaging devices
  • Support informed clinical decision making
  • Increase patient awareness.

Imaging exams should be conducted only when medically justified. When such exams are conducted, patients should be exposed to an optimal radiation dose – no more or less than what is necessary to produce a high-quality image. In other words, each patient should get the right imaging exam, at the right time, with the right radiation dose.

Be a health-wise consumer.
Given the positive benefits of CTs and other imaging exams, how can you become a scan-savvy consumer of medical radiation? Image Wisely, an organization sponsored by the ACR and RSNA which is working to reduce, and ultimately eliminate unnecessary ionizing radiation exposure, advises that patients begin by talking to their healthcare providers, and asking the following questions before receiving a medical scan:

  • How will this exam improve my care?
  • Are there alternative imaging exams that don’t use radiation?

Additionally, as a wise healthcare consumer you can guard against overexposure to radiation by making the attending physician aware that you do not want to be subjected to repeated scans without discussing pros and cons first. Of course, in an emergency situation, it is always prudent to listen to the best council of your physician, given the importance of timely action.

When it comes to medical radiation, as with any product or service, it is our responsibility as consumers to educate ourselves as thoroughly as possible, about the benefits and dangers of the technology. For more information about CT scans and other imaging technology visit www.imagewisely.org.

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