Technological aspects and early clinical experiences are arousing great enthusiasm over magnetic resonance imaging (MRI). However, influences such as regulation, reimbursement, and increasing competition also are playing important roles in determining the diffusion of this new technology. Of these considerations, competition among providers seems the most important. Competition related to MRI is manifested as direct competition over MRI services, using MRI to improve a provider's strategic position and competition among specialties. In making decisions concerning MRI acquisition and operation, providers are drawing upon their experiences with computed tomography (CT) to help them determine when would be the best time for acquisition, how to decide whether acquisition is appropriate, and how best to acquire, operate, and market the technology.