Magnetic resonance imaging (MRI) is a non-invasive imaging technique used in hospitals and clinics to produce detailed soft tissue anatomical images through emission and absorption of energy of the radiofrequency range of the electromagnetic field by employing powerful magnets that produce a strong magnetic field around the area to be imaged without exposing the body to ionized radiation. A traditional MRI scan (closed/high field), which typically takes between 20 and 60 minutes, involves the patient lying inside a tightly enclosed and narrow tube. Between 1% and 15% of all patients scheduled for magnetic resonance imaging suffer from claustrophobia and cannot be imaged or they require sedation to complete the scan. Also, large persons cannot fit into the tube aperture.
Open MRI scanners are an alternative to conventional scanners. In an open MRI, the patient is positioned between two plates with the option of standing or sitting for some types of examination. It allows large and claustrophobic or anxious patients to be scanned properly. Because of the easy access to the patient, they are also useful in image-guided interventions and intraoperative imaging.
Compared to closed-MRI scanners, open MRI-scanners have weaker magnetic fields and lower volume and uniformity of the gradient magnetic field, affecting image quality, though this can be partially compensated with extended examination, but longer times may increase the likelihood of motion artefacts and reduce patient throughput.