Magnetic Resonance Imaging (MRI) is a powerful diagnostic tool that allows physicians to see detailed images of the inner tissues and structures of the human body using a combination of magnets and a strong magnetic field. MRI technology is safe, non-invasive, and, unlike traditional x-ray or CT scanning, completely free of radiation.
The MRI machine itself resembles a large tunnel with a moveable table that can slide into the tube. The patient lies on the table and the table is moved into the tunnel to perform the scan.
The tunnel houses two large electromagnets and a strong radio frequency (RF) generator. First, the magnets generate a power magnetic field around the patient. The patient is then subject to a rapidly pulsating radio frequency (RF) field — this pulsing creates a thumping or hammering sound within the tunnel.
The basic principles which make MRI scanning possible are well-established.
The human body is largely made up of water molecules. These water molecules are made up of two hydrogen atoms and one oxygen atom, and at the heart of each atom lies a proton. Protons, like magnets, have a natural north and south pole. Protons also react in a strong magnetic field, just like a magnet, by aligning their north-south poles with that field.
When the patient enters the MRI, the magnetic field is turned on. This aligns all the protons in the hydrogen atoms in the patient’s body in one direction. The RF generator is then rapidly pulsed on and off. This pulsing causes the protons to rapidly spin out of and then back into magnetic re-alignment with the magnetic field.
Sensors within the MRI machine are able to measure the amount of energy released when the protons realign with the magnetic field. This amount of energy and the time it takes the protons to realign differs between different molecules and is used to determine what kind of tissue is being examined. Powerful computers in the MRI machine then use this information to create highly detailed images of the area of the patient’s body that is being scanned.
MRI scans have become an invaluable diagnostic tool capable that can help physicians diagnose and treat patients with an unequaled level of precision not available with other medical imaging technologies.
At Hampton Roads Orthopaedics & Sports Medicine, we use an Upright MRI machine that is designed to be more comfortable for the patient. If you suffer from claustrophobia, back pain, arthritis, or have any other condition that may limit your ability to lie in a traditional MRI machine, we can accommodate your needs. Our team of providers are ready to answer any questions you may have about this and other diagnostic tools.