Fall 2004 Volume 16, Number 4	Touting the Tiptop 3T Outpatient's new scanner is the last word for imagining brain subtleties and more.
	The new 3T (for tesla) MRI in Hopkins' Outpatient Center harbors such a strong magnetic field that it could tug the snaps off a jacket. It could jiggle the metallic particles in permanent eyeliner. But most important about the higher field-strength is the fact that it brings new clarity to images of brain and spinal cord.
"We're getting significantly improved MR angiograms of the brain," says neuroradiology director David Yousem, M.D., Ph.D., who helped usher in the device that began operation last spring. The scanner's higher resolution improves ability to detect aneurysms, vascular stenoses, multiple sclerosis plaques and subtle tumors. Three tesla MR scanners aren't common in the Baltimore-Washington area-only two or three exist. The Kennedy Krieger Institute has had a research 3T imaging scanner for two years; in that time its radiologists and neurologists honed it for novel studies on a variety of brain disorders. This newest machine, however, is the first in the area to do clinical imaging. It's taken time to develop the specialized coils and MR pulse sequences that will let it perform under more demanding, high-volume patient use. So far, the scanner has been used mostly for neuro-imaging. That's because only brain or spinal cord-adapted surface coils-the localized antennas that relay signals-have been available. Coils for other body areas are getting finishing touches from the maker, Philips Electronics. "We're absolutely cutting edge," says Yousem, "and it's a good feeling." Plans are under way to replace the hospital's other 1.5T scanners. Beyond the realm of traditional scanning, the 3T machine also lends itself to functional MRI (fMRI). Its strength brings new ability to detect shifts in blood supply that signal higher or lower tissue activity-the hallmark of fMRI-and greatly increase surgical accuracy. "Say there's unexpectedly high brain activity posterior to a tumor," says Yousem. "You'd suspect that's an eloquent area and change your tumor approach." Improved MR spectroscopy is another benefit. Clinicians may, for example, follow healing of a brain infection by monitoring changes in levels of key molecules. A unique use may come with diffusion tensor imaging, a technique nurtured by neuroradiologist Susumu Mori, M.D., to map white matter fiber tracts in the brain (see this winter's Brainwaves.) It's currently the only way to do this in living patients. Diffusion tensor imaging should help define tumors as well as tell how broadly white matter has degenerated in diseases like ALD (see page 6) or multiple sclerosis. Patients entering the scanner suite will find it both attractive and user-friendly. And the machine itself has a broader "tunnel" than other 3Ts available, Yousem says, "so there's less of an issue with claustrophobia." Also, the control room has multiple video monitors to report on the MRI room. Operators can see patients from head to toe. "Not having the usual glass window between the two rooms allows us to stop leaks in the magnetic field," Yousem explains, "and gives the best quality image."