Magnetic resonance imaging (MRI) is a scan used for a medical imaging procedure. An MRI uses a magnetic field and radio waves to take pictures of the body’s interior. An MRI is used to investigate or diagnose conditions such as tumours, joint or spinal injuries or diseases, soft tissue injuries or diseases of internal organs such as the brain or heart.
Magnetic resonance imaging (MRI) is a scan used for a medical imaging procedure. It uses a magnetic field and radio waves to take pictures inside the body. It is especially helpful to collect pictures of soft tissue such as organs and muscles that don’t show up on x-ray examinations.
One way to think of an MRI scan is a water ‘x-ray’ (although no actual x-rays are involved). Normal x-rays image calcium, so they are good to see bones. MRI scans image water, which makes them very useful because all tissues of the body contain various amounts of water. This allows high-resolution pictures of many organs and tissues to be taken that are invisible to standard x-rays.
The MRI scan consists of a table that slides into a large cylinder. Inside the cylinder is a magnet that, when operated, creates a powerful magnetic field.
Soft tissue contains water molecules and the magnetic field acts upon microscopic substances (called protons) found in water. The magnetised protons in the soft tissue send out an echo in response to the MRI scan’s radio waves. A computer then organises these echoes into images.
The MRI scan operator (radiographer) can take cross-sectional images of the patient’s body from almost any angle.