The market for 3T MRI is undoubtedly growing. Five years ago, few sites were using a 3T scanner for anything other than research. Now the higher field strength devices can be found in many clinical radiology departments and outpatient imaging clinics across the U.S. Clinical 3T is making inroads in Europe, too, though at a pace commensurate with its smaller MR base.

Few doubt the ability of 3T to reveal exquisite detail on brain MR imaging. The argument for higher field strength scanning of small joints also appears cut and dried. The true test of 3T, however, is whether it can excel in areas of interest to general radiology. This level of acceptance may only be a matter of time, according to evidence gathered from the maturing technology.

Difficulties in maintaining field homogeneity over a wide area have traditionally restricted 3T MRI studies to small fields-of-view. Increasing the magnetic field strength means more eddy currents, more distortion, and less field uniformity. These problems can, in theory, be countered by increasing the scanner's bore and diameter.