Molecular what?

By Greg Freiherr, Editor, gfreiherr@cmp.com

A lot of imaging today seems to revolve around molecules. It's easy to assume this is a good thing. The term "molecular imaging" just naturally conjures up a feeling of precision. It's as though our technology has made a huge leap forward, and now, after a century of trying, we're getting down to the molecular bedrock of health and disease.

Much of this progress, it seems, has been made in just the last few years. Before then, molecular imaging didn't come up much. Looking back at SCAN stories, I didn't find a single mention before 1998. The same was true for Diagnostic Imaging magazine, which published its first story about molecular imaging that year.

Molecular imaging popped up the next year in only two DI stories (none in SCAN). But then something happened. In 2000, it went gangbusters: 13 stories mentioned molecular imaging in DI that year (one in SCAN). The next year saw 39 stories in DI and 15 in SCAN.

If molecular imaging was a brand new modality, I'd say this was significant. The fact that it's not is reason to worry. This term is actually the antithesis of itself. Rather than adding precision, its use blurs our understanding. When somebody says molecular imaging, I have to ask what they mean.

Is it MR spectroscopy? PET? Are gamma cameras involved? How about optical coherence tomography? Or its cousin, diffusion optical tomography? CT is getting into the act, characterizing plaques according to the risk of heart attack. The only modalities that have yet to jump in are ultrasound and radiography/fluoroscopy, and I expect their time is coming.

Modalities soon will have to be capable of molecular imaging to be considered state of the art. Already this year, 26 DI and 12 SCAN stories (bump it up a little higher if you count this issue) have mentioned molecular imaging. Not surprisingly, a lot of people who use this term aren't really sure what it means.

Not long ago, a company rep described one product but not another as involving molecular imaging. Then he said both products involved molecular imaging, and concluded that only one really involved it but the other probably would soon.

We need to take a step back before this gets totally out of control. Let's not forget that the big vendors in our industry all have extensive portfolios of consumer products. If we don't draw the line now, can molecular toasters and light bulbs be far behind?