Siemens Healthcare's newly installed CEO passed around his brain to attendees at the Radiological Society of North America's annual conference in Chicago last week - well, a plastic replica of his brain.

In a talk celebrating new advances in imaging technology, especially as it relates to understanding the brain, Dr. Gregory Sorensen, a neuro-radiologist who took the reins at Siemens' health care business in the spring, had his daughter pass around a copy of his brain. The model was created by a 3-D printer based on his own brain scan.

"We brain imagers have just had a blast in the last couple of decades," he said during his talk, RSNA's annual Eugene P. Pendergrass lecture.

In the talk, called "Mechanistic Imaging—MR-PET, 7 TESLA MRI and Beyond," he outlined how new technology such as the recently launched hybrid PET-MR scanners and yet-to-be commercially available 7-T MRIs could aid in fighting the scourge of "misdiagnosis," which he characterized as one of the big health care challenges of the coming decade.

While surgical and medication errors have made headlines - Sorensen cited the case of Betsy Lehman, a newspaper columnist who died in 1994 after accidentally receiving a chemotherapy overdose - misdiagnosis is also a serious problem. About 40,000 to 80,000 patients die every year in U.S. hospitals because of misdiagnosis, he said. (The numbers come from a 2002 Journal of the American Medical Association article.) And improving diagnoses is where new imaging technologies, of course, really stand to make a difference.

Unraveling the brain

Another area that could benefit by new technologies is the brain. Sorensen noted that it has some unique challenges: for one, it's the only organ where there's no histological trace for many disorders, he said. (A slide of brain matter under the microscope won't reveal evidence for most psychiatric problems, for instance.) Also, many experts can't agree even on how many cell types make up the brain.

Plus, the global health and economic toll from neurological and psychiatric disorders is immense. For instance, Sorensen said the world's leading culprit for disability-adjusted life years lost is depression (cardiovascular disease comes in at number two). And at least six of the top 10 global health threats involve the brain - from alcoholism to traffic accidents.

But in imaging, progress is being made. For example, scientists have developed imaging algorithms to generate mathematical models of the brain, "smoothing" out the coils to allow doctors to better assess the thickness of certain regions. With this, for example, scientists have shown that some areas, such as the temporal lobe, experience greater loss of thickness than is normal for aging in those with Alzheimer's disease.

Brain imaging techniques also have possibly more frivolous uses. Sorensen brought up a recent study showing that people with many friends on Facebook have more neurons in a certain region of their brain.

"If you're a more social person, you develop more social neurons," he said, adding that he's reminded by his wife that he has "exactly four social neurons."

7-T MRI, PET-MR

Two promising new technologies include 7-T MRI and PET-MR. PET-MR is already on the market: Siemens' Biograph mMR, the first fully integrated such scanner, received Food and Drug Administration clearance earlier in the year, while Philips Healthcare announced at the show that its dual-scanner unit also got FDA's OK.

This technology, which Sorensen said was being used in cancer research, has already passed what he dubbed the "phone call test" - that is, people around the country are calling him and asking about it. And he foresees an especially strong demand from the "dose-conscious pediatric community," as swapping out CT for MRI for attenuation correction could result in lower radiation doses to children during scanning.

7-T MRI is further away from the clinic. GE, Siemens and Philips all make 7-T scanners, but all are in the investigational stage, and none has been cleared by the FDA. Still, Sorensen said early work on 7-T has shown it's promising for brain research. For example, there's evidence that cerebral arteries that are invisible on 1.5-T scanners can be seen on 7-T, and that doctors might be able to better see micro-bleeds. It also could be useful in picking out brain lesions in multiple sclerosis patients.

Of course, 7-T MRI is also a money-eater. Literally, in the case of a video Sorensen showed, in which a rolled-up dollar bill was actually drawn towards the 7-T's bore, because of the device's powerful magnet.

"We said the 7-T just sucks up money," Sorensen joked.