Article:
Magnetic resonance imaging (MRI) is a type of scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of the body. An MRI scanner is a large tube that contains powerful magnets. You lie inside the tube during the scan. An MRI scan can be used to examine almost any part of the body, including the: brain and spinal cord bones and joints breasts heart and blood vessels internal organs, such as the liver, womb or prostate gland The results of an MRI scan can be used to help diagnose conditions, plan treatments and assess how effective previous treatment has been. What happens during an MRI scan? During an MRI scan, you lie on a flat bed that is moved into the scanner. Depending on the part of your body being scanned, you will be moved into the scanner either head first or feet first. The MRI scanner is operated by a radiographer, who is trained in carrying out X-rays and similar procedures. They control the scanner using a computer, which is in a different room to keep it away from the magnetic field generated by the scanner. You will be able to talk to the radiographer through an intercom and they will be able to see you on a television monitor throughout the scan. At certain times during the scan, the scanner will make loud tapping noises. This is the electric current in the scanner coils being turned on and off. You will be given earplugs or headphones to wear. It is very important that you keep as still as possible during your MRI scan. The scan will last between 15 and 90 minutes, depending on the size of the area being scanned and how many images are taken. 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. The MRI scan is used to investigate or diagnose conditions that affect soft tissue, such as: Tumours, including cancer Soft tissue injuries such as damaged ligaments Joint injury or disease Spinal injury or disease Injury or disease of internal organs including the brain, heart and digestive organs. The MRI scan provides clear and detailed images of soft tissue. However, it can’t ‘visualise’ bone very well, since bone tissue doesn’t contain much water. That is why bone injury or disease is usually investigated with regular x-ray examinations rather than MRI scanning.