Medical MRI scanner Magnetic resonance<unk>  (MRI) is in general a safe technique, although injuries may occur as a result of failed<unk>  procedures or human error. During the last 150 years, thousands of papers focusing on the effects or side effects of magnetic or radiofrequency fields have been published. They can be categorized as incidental and physiological. Contraindications to MRI include most cochlear implants and cardiac pacemakers, shrapnel and metallic foreign bodies in the eyes. The<unk>  of MRI during the first trimester of pregnancy is uncertain, but it may be preferable to other options. Since MRI does not use any ionizing radiation, its use generally is favored in preference to CT when either modality could yield the same information. (In certain cases, MRI is not preferred as it may be more expensive, time-consuming and claustrophobia-exacerbating).
Safety of magnetic resonance imaging
Physics of magnetic resonance imaging
Instruments used in gastroenterology
Diagnosis of hearing loss
Sex differences in humans
Pain in animals
Causes of cancer pain
Instruments used in urology