Magnetic Resonance Imaging (MRI / NMRI)

Magnetic resonance imaging (MRI), also referred to as NMRI, is a non-invasive test physicians use to diagnose medical conditions without exposing the patient to ionising radiation, unlike conventional X-ray or CT scanning. It works by placing the patient in a powerful magnetic field, generated by passing electric current through wire coils inside the scanner, while additional coils send and receive radio-frequency pulses. These radio pulses temporarily re-align hydrogen atoms that occur naturally throughout the body's tissues, without producing any chemical change; as the hydrogen atoms then relax back to their normal alignment, they emit small amounts of energy that vary depending on the type of tissue they are located in. The scanner detects this emitted energy and a computer processes the signals into a series of images, each representing a thin slice of the body, which can be examined from different angles, transmitted digitally, printed, or interpreted directly by a radiologist. Because the electric current used to generate the magnetic field never touches the patient, and no ionising radiation is involved, MRI is considered very safe for repeated use. MRI is particularly good at distinguishing diseased (abnormal) tissue from normal tissue, often better than X-ray, CT or ultrasound, which is why it is the preferred choice for evaluating soft tissues and blood vessels - for example, visualising torn ligaments in joints such as the wrist, ankle or knee. Clinically, MRI of the body is used to evaluate organs of the chest and abdomen, pelvic organs including the bladder and repr …