1.5 Tesla magnetic resonance imaging scanner versus 3.0 Tesla magnetic resonance imaging scanners

Magnetic resonance imaging (MRI) is a tool used for the diagnosis and evaluation of various diseases and indications. An MRI scanner emits a strong magnetic field that aligns the nucleic spin orientation of atoms in the body and uses radio frequency fields to systematically alter the alignment of this magnetization. As the alignment is altered, the nuclei produce a rotating magnetic field that can be detected by the scanner and used to construct an image of the scanned area. The magnetic field strength that is most commonly used for MRI is 1.5 Tesla (T), but increasingly more powerful magnet strengths such as 3.0 T are available. Increasing magnet strength to 3.0 T has the potential to improve the signal-to-noise ratio (SNR) compared to 1.5 T due to an increased signal detected from tissue with relatively less increase in background noise, which can improve spatial and temporal resolution. Contrast agents such as gadolinium may be administered intravenously to the patient prior to imaging in order to further improve visibility of body structures at any magnetic field strength. Improved resolution of scanned images at higher magnetic field strengths such as 3.0 T may improve the accuracy or confidence with which a diagnosis is made compared with lower magnetic field strengths. While there are potential advantages of using 3.0 T MRI regarding resolution, there are potential disadvantages of higher magnetic field strengths including increased susceptibility to artifacts, increased vigilance required for patient screening with regards to implanted devices, increased risk of adverse events such as dizziness, and increased cost of equipment purchase, installation, maintenance and operation. The purpose of this review is to assess the diagnostic accuracy, reliability, diagnostic impact, clinical impact, and cost-effectiveness of 3.0 T MRI compared with 1.5 T MRI, as well as guidelines for the use of 3T MRI. This review is focused on specific clinical indications: epilepsy, brain tumours, stroke, musculoskeletal imaging,