Advances In Imaging Technology

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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.

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 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, 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 obese are often less accurate in general than for people of average weight.

Using Imaging for Routine Screening — the Pros and Cons

A topic that’s spurred interest — and debate — is screening apparently healthy people for cancer, heart disease, and other problems. Sophisticated imaging tests can sometimes detect disease in very early stages, long before a person shows any other symptoms.

So given the obvious benefits, why isn’t everyone in America being screened? It turns out that there are some real drawbacks to routine screening.

First of all, imaging has risks. Many tests involve exposure to small amounts of radiation or radioactive material. While the odds that this could cause harm are low, they still exist, says Eversman.

The other problem is that screening can detect abnormalities that don’t actually need any treatment. But once the doctor sees them, further tests must be ordered to make sure that these abnormalities are harmless. So people may need a number of tests or even surgery — and suffer a lot of anxiety – only to discover that they didn’t need treatment!

“There are a lot of nonspecific abnormalities,” says Hillman. “For instance, an enormous number of people have nodules in their chests. But only a fraction of them actually turn out to be cancer.” Universal screening could lead to a lot of unnecessary and risky tests and procedures.

Even in apparently healthy people who really do have a disease, screening may not always help.

“Catching the disease early and stopping it would be great,” says Hillman. “But lots of times, that doesn’t happen. You find the disease earlier, you treat it earlier, but the outcome is the same and the person dies anyway.” Early detection helps many people, of course. But it doesn’t always make a difference. For those who aren’t helped, it leads to tests, treatments, and intense distress much earlier than someone who wasn’t screened.

Smarter Use of Imaging for Screening

As for now, no one recommends routine high-tech screening for everyone.

“The American College of Radiology does not endorse whole body screening of healthy people,” says Eversman. “It probably shouldn’t be done, since there’s no proof that it saves lives or even improves them.”

“I think it’s fair to say that at this point, the only cancer screening that we know to work in reducing the death rate is mammography,” Hillman tells WebMD. “Everything else is undergoing testing or completely unproven.”

But experts are trying to figure out how to use screening as a tool for people at higher risk of certain diseases. Lewin also says that as imaging exams become safer and more accurate, the pros of screening may outweigh the cons.

“As MR screening continues to improve, and as we lower the dose of radiation with CT, routine screening will make sense for a bigger and bigger proportion of people,” he tells WebMD.

Imaging Moved Into the Operating Room

Soon, imaging tests may not only be used to diagnose disease. They may also become a key part of some medical procedures. During minimally invasive surgery, imaging will allow surgeons to see inside the body better, to improve treatment — and minimize complications.

“Minimally invasive surgery and new imaging technologies are developing hand in hand,” says Lewin.

“MRI in particular — but also other technologies, like ultrasound — may have the ability to monitor a surgery in real time,” says Hillman. “They could potentially detect when all of a tumor was removed, or when a surgeon was accidentally beginning to harm normal tissue.”

Lewin says that using MRI during brain surgery is already helping. “The studies are still being done,” he says. “But I’ve seen that combining the surgeon’s with MR improves the operation. Because the human eye, even with a microscope, just can’t see what an MR can see.”

Eversman says that CT scans are starting to be used to create computer-generated models of the heart for use during surgery. “During the operation, the 3D model is shown on a screen, and it moves and rotates to show where the surgeon currently is in the heart,” he tells WebMD. “It’s a great innovation.”

Experts say that imaging will become even more detailed and focused in the future.

“In the next 20 years, imaging technology is going to focus on the molecular and cellular levels,” says Hillman. “Instead of only seeing the gross anatomy like we do now, we’re going to be looking at metabolism and physiology.” He says that PET scanning is the first step in this direction.

In general, imaging technology is certain to become faster and more accurate. More combination devices — like the CT/PET scan — are inevitable. “There are some prototype PET/MR scanners now,” says Hillman. “And people are talking about CT/MR scanners.” Fusing different imaging techniques will allow doctors to get a much fuller understanding of a person’s condition.

“In our lifetimes, I don’t think that we will reach the technology of Star Trek, where you can wave a wand over someone and instantly diagnose them,” says Eversman. “But step by step, we’re getting there.”