MRI (Magnetic Resonance Imaging) uses a magnetic field to help produce images. The strength of the magnetic field is critical to how clearly the image comes out. The units for magnetisim is the Tesla. When it comes to MRI there are three classifications for magnet strength.
Low Field (Commercially known as Open MRI)- Usually 0.2 Telsa. Open MRI machines were designed to create a larger opening for obese and highly claustraphobic patients. The trade-off between the larger opening on an Open MRI is lower magnet strength which creates lower resolution images when compared to a high-field MRI. Manitoba does not use Open MRI.
High-Field MRI- 1.5 Telsa. This is generally agreed upon as the standard of care by radiologist and physicians. While the bore is smaller, these machines consistantly produce diagnostic quality images. In cases of less than severe claustraphobia patients are usually encouraged by their doctor to take a sedative and use High-Field before they are directed to an open mri machine. All but one of the MRI units in Manitoba and the majority of the MRIs across the U.S. are 1.5 T.
Ultra High-Field MRI- 3 Telsa. This is considered a research grade MRI. They produce the sharpest images and can complete sequences the fastes. For this reason they are often used by universities for nurological research however they are also applied in clinical settings. Cost of the equipment reduces access to these machines.