Magnetic resonance imaging systems: evaluation of 1.5-Tesla systems

Magnetic resonance imaging (MRI) systems manipulate magnetic fields and radio-frequency signals to create diagnostic images of human anatomy. An MR system is an essential clinical tool, but the cost of buying and installing one is high, so it's crucial that hospitals choose a model carefully. The selection process is made more complex by the numerous options available: different field strengths, gradient systems, coils, and channels, to name just a few. Also, some systems are better than others at facilitating specialized imaging, such as breast and cardiac studies. Our Evaluation is intended to help clarify the choices. We tested three 1.5-tesla systems from three suppliers--GE, Siemens, and Toshiba. We rate the systems for two different uses: inpatient imaging (performed in hospitals) and outpatient imaging (most often performed in imaging centers). For inpatient facilities, which are likely to have less responsive patients and to treat more complex medical problems, the most important purchase considerations will be patient positioning features, advanced imaging capabilities, and system integration. For outpatient facilities, the ability to perform routine exams efficiently and comfortably will be most important. We also provide separate ratings for each system's ability to meet the needs of three specialized applications--breast imaging, cardiac imaging, and functional MRI.