Neuroimaging with MRI at 3T is superior for nearly every application in the brain and spine, and it is certainly inferior for none. The technique has unique strengths for performing vascular work and functional brain imaging, but there is nothing that a 3T MR scanner can't do better than a 1.5T machine.

While 3T poses technical challenges, such as an increased specific absorption rate (SAR), tools are available to master them. The only major deterrent to more widespread 3T use—its fundamentally higher cost—is dissipating as clinical imaging centers make a strong financial case for the technology.

"Over the last four to five years, 3T MRI has become more and more common in the clinical practice setting," said Dr. Lawrence Tanenbaum, director of MRI at Mount Sinai School of Medicine in New York City.

Nearly all academic medical centers have one or more 3T scanners, he said, noting that the trend is toward making 3T MRI the standard of care.

"Although the Deficit Reduction Act has slowed implementation a bit, fortunately for people who want to see 3T succeed, the law came fairly late in the process, after the adaptation of 3T was inherent to what everybody was doing in clinical practice," he said.

Perhaps the biggest emerging area for 3T MRI is the shift toward volumetric imaging. Just as CT went to volumetric imaging with center slices, borne on multichannel scanners, that could be constructed in any plane in 2D and 3D, volumetric imaging is available now for MR scanning.

Volumetric imaging's dependence on the slice thickness and resolution that can be created from source data makes it more feasible at 3T than at lower fields because 3T is more powerful and generates more signal, Tanenbaum said.