Recent advances in imaging technology -- like CT scans, MRIs, PET scans, and other techniques -- have had a huge impact on the diagnosis and treatment of disease.
"Advances in imaging over the last five years have revolutionized almost every aspect of medicine," says Jonathan Lewin, MD, chairman of the department of radiology at Johns Hopkins School of Medicine in Baltimore.
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More detailed imaging is allowing doctors to see things in new ways. Imaging can provide early and more accurate diagnoses. In some cases, it might even lead to better and more successful treatment.
"Just about every field of medicine is using imaging more than they used to," says William Eversman, MD, chairman of radiology at the Mayo Clinic in Scottsdale, Ariz. "I'm not saying that the physical exam is a dying art. But doctors are coming to see just how valuable and accurate these tests can be."
Four Big Advances in Imaging
There have been many improvements to imaging technology in recent years. Here are a few that experts singled out as especially significant. While these are becoming more common, keep in mind that the newest technology may not be available yet at your local hospital.
"CT angiography is one of the greatest advances in imaging," says Lewin.
Just a few years ago, an angiography -- an examination of the blood vessels -- could only be done by inserting a catheter into an artery. In the procedure, contrast material -- a substance that makes it easier to see tissue in an X-ray -- is injected through the catheter. Then an X-ray is taken of the area to look for blockages, internal bleeding, or other problems. Catheter angiography can take up to several hours. It often requires sedatives and sometimes a night in the hospital. It also has risks, like a small chance of blood clots or bleeding.
"The newest CT scans allow a completely noninvasive way to get the same information as an invasive catheter angiography," says Lewin.
In a CT angiography, the doctor just injects the contrast material into the arm and takes a CT scan. The arteries in the lungs, kidneys, brain and legs can then be examined. The whole process takes just 10-25 minutes. It's safer, faster, and cheaper than the traditional way.
CT angiography hasn't completely replaced the old technique. For example, traditional angiography is still commonly used to evaluate heart arteries for blockages.
Imaging Tests Instead of Exploratory Surgery
One of the biggest changes in the use of imaging, says Hillman, is that it has largely replaced exploratory surgery.
"In the past, we had to do surgery just to see what was going on inside the body," says Hillman. "But CT scans, MR scans, and ultrasound have become so good that they have largely done away with the need for the surgical approach."
PET (positron emission tomography) scanning is not new. But it has become increasingly important in recent years, particularly since it was combined with CT scanning in one device.
"PET scanning has been around for a long time," says Hillman, who is also a professor of radiology at the University of Virginia. "But for years no one was sure just what to do with it."
PET scans are a type of "nuclear medicine." The name is unnerving. But "nuclear" refers to the small dose of radioactive material that you are injected with before the test. The amount of radiation exposure is similar to what you would get from a standard X-ray.
Unlike many other imaging technologies, PET scans aren't designed to look at organs or tissue. Instead, they can image biological functions, like blood flow or glucose metabolism. "PET is able to pick up the metabolic changes associated with cancer much earlier than you could see tumors or other physical changes in the organs," says Lewin.
PET/CT scans give a doctor a broader view of a person's condition.
"By fusing PET and CT," says Lewin, "you get to see both the metabolic information of PET and the anatomic detail of CT at once. It's a big advance."
"Digital mammography for breast cancer screening is a significant leap forward," says Lewin. "It gives us a much higher level of detail than older technology."
Digital mammograms produce similar results to traditional mammograms, which use X-rays and film. But the digital approach has several advantages. Bruce J. Hillman, MD, chairman of the American College of Radiology Imaging Network, notes that digital mammograms are easier and faster to perform. And since they are digital, it's very easy for a doctor to send the images instantly to other experts or medical centers.
Early studies showed that digital mammography worked as well as traditional mammography in detecting breast cancer. A 2005 study published in The New England Journal of Medicine found digital mammography was actually more accurate for some women. This includes women who were under 50, women with dense breast tissue, premenopausal women, and women who were around the age of menopause.