Nuclear Medicine & Radiology: A Whole New Integrated World

The development of molecular imaging has not only had a profound impact on medical practice and imaging, but on the relationship between the two established specialties of radiology and nuclear medicine.

On the one hand, the relationship has long been seen to be a cooperative one. “Really, radiology and nuclear medicine have been working together ever since 1971 [when the American Medical Association officially recognized nuclear medicine as a medical specialty],” says SNM President Michael Graham, MD, PhD. “And most nuclear medicine departments—though not all—are part of radiology departments, so we work with radiologists every day.”

On the other hand, changes over the last decade or so—particularly the development of hybrid technologies such as PET/CT and SPECT/CT—have further intertwined and complicated the relationship between radiology and nuclear medicine. Yet Graham, who also is professor of radiology and director of nuclear medicine at the University Of Iowa Carver College Of Medicine in Iowa City, believes these developments have led to an even closer integration of the two specialties.

For example, according to Graham, there has been—on both sides of the specialty divide—a mutual effort to become better educated. “Both SNM and a number of radiological societies have put together a number of courses for radiologists on PET/CT imaging and the same organizations have put together courses for nuclear medicine physicians to learn about anatomical imaging,” says Graham.

The Radiological Society of North America (RSNA) is “probably the most active radiological organization that is presenting a lot of educational material on molecular imaging,” says Graham. And a look at the education offerings relating to molecular imaging at this year’s RSNA annual meeting confirms Graham’s observations—dozens of molecular imaging-related topics were on the agenda.

This shift towards placing more emphasis on molecular imaging in RSNA’s (and other organization’s) educational offerings was one of the recommendations made by a group of scientists and physicians who met for a “summit”—convened by RSNA and SNM—on molecular imaging back in 2005. “It was held to try and reconcile the different perspectives on molecular imaging,” says former RSNA President Brian Lentle, MD, professor emeritus and former head of the Department of Radiology at the University of British Columbia in Vancouver, who co-authored a report on the results of the summit that ran in both The Journal of Nuclear Medicine and Radiology in 2005. “RSNA immediately went ahead and developed a molecular imaging group that has been quite effective and since then there has been a greater presence in molecular imaging at the annual meeting.”

While there is plenty of evidence that the relationship between the two specialties has been collaborative and cooperative, circumstances have muddled that relationship as well. “Radiology has encountered turf issues in multiple areas over the years,” says Graham, and Lentle observes that while the two specialties live together in multiple imaging departments, “it’s never quite been that marriage made in heaven that it should be.”

Lentle believes it has to do with perspective—the fact that radiologists “typically look at structure and nuclear medicine physicians look at how things work.

“You would think that working together you could gather the best possible information,” adds Lentle. “And I think that’s true—that’s what PET/CT is all about.” Instead, PET/CT has, Lentle observes, muddied the line between radiology and nuclear medicine in a way that contributes to talk about “turf wars” between the two specialties.

Graham acknowledges that while issues like PET/CT create concerns about turf, the relationship between nuclear medicine and radiology is “more cooperative than that.” For example, he points out that there aren’t any identifiable large clinical or reimbursement opportunities in molecular imaging that could create a significant amount of competition between the specialties. He also posits that if there was such an overwhelming concern with turf, then radiologists and nuclear medicine physicists would be climbing all over each other in the area of magnetic resonance (MR) spectroscopy, an area that hasn’t developed as rapidly as most observers would have suggested, Graham says. The specialized technique requires a lot of personal involvement with patient acquisition, and thus it isn’t widely used. Interpretation is often difficult and confusing since similar spectral patterns can mimick various diseases. It does occasionally provide supportive evidence to diagnosis but there has been a gradual shift away from spectroscopy due to this lack of specificity.

MR spectroscopy falls within the area of functional imaging, which is what nuclear medicine does. The problem, says Graham, is that nuclear medicine physicians have few opportunities to use the technique. “It’s not to say it’s not used at all,” he says, “but it is underutilized because of its funny position between the two specialties. It’s just the opposite of a turf war.”

Still, the awkward PET/CT issue is still somewhat of a sticking point in the relationship between the two sides, Graham says, as long as nuclear medicine physicians lack the skills to read CT and radiologists have to defer to nuclear medicine physicians in reading PET. “Two people have to read the thing,” he says, “and it makes everything much more complex in terms of getting the work done. That’s why it is so important for radiologists to become competent in PET and nuclear medicine physicians in CT.”

The ramifications of developing these multidisciplinary competencies transcend issues involving workflow and patient care and treatment, but reimbursement issues as well. “Which, in turn, means being credentialed,” Graham points out. And there is a change in the way residents are being trained in nuclear medicine and radiology, says Graham. “We are insuring that our nuclear medicine residents get four months of experience in CT while they are in their nuclear medicine program, so they will get the experience they need to get credentialed when they complete the program,” he says.

Going forward, Graham believes the accomplished molecular imaging physician of the future will be dual-board certified in both nuclear medicine and radiology. “I’m pushing for that,” says Graham. “We have a joint task force between SNM and ACR [American College of Radiology] that is addressing the future training of nuclear medicine physicians and this is one of the pathways that is very much on the agenda.”

What Graham would like to see established is an “interleaved” radiology/nuclear medicine training program that would take five years to complete and would include two years of nuclear medicine training and three years of radiology. “But it would be heavily interleaved so that at the conclusion of the program the resident would truly be up to speed in both areas,” says Graham. “In terms of board requirements for both the American Board of Nuclear Medicine and the American Board of Radiology, this fits in with their requirements very nicely. So there are no requirement for changing the rules, just a matter of implementing this so there is a way to schedule it so that it fits in with existing radiology and nuclear medicine training programs.

“Lentle agrees that a focus on training and education will help to further integrate the two specialties, but also suggests that the passage of time will help as well. “Physicians who’ve grown up with PET/CT are getting used to talking across specialty barriers,” Lentle says. “And as my generation moves out into retirement and younger people come into the field…time and education will have their own effect.”