| What is MRI? | | | | An MRI scan is a painless radiology technique |
| | | | that has the advantage of avoiding x-ray |
| MRI stands for "Magnetic resonance imaging | | | | radiation exposure. There are no known side |
| and was formerly referred to as magnetic | | | | effects of an MRI scan. |
| resonance tomography or "MRT" in scientific | | | | |
| circles. MRI was originally marketed by big | | | | Things to know before an MRI scan. |
| corporations such as GE as a non-invasive | | | | |
| method used to render images of the inside of | | | | The benefits of an MRI scan relate to its |
| an object. | | | | precise accuracy in detecting structural |
| | | | abnormalities of the body. |
| MRI should not be confused with the NMR | | | | |
| spectroscopy technique used in chemistry, | | | | A. Patients who have any metallic materials |
| although both are based on the same | | | | within the body must notify their physician |
| principles of nuclear magnetic resonance. In | | | | prior to the examination as well as inform |
| fact MRI is NMR applied to the signal from | | | | the MRI staff. Metallic chips, materials, |
| water to acquire spatial information in place | | | | surgical clips, or foreign material |
| of chemical information about molecules. The | | | | (artificial joints, metallic bone plates, or |
| same equipment can be used for both imaging | | | | prosthetic devices, etc.) can significantly |
| and spectroscopy. The scanners used in | | | | distort the images obtained by the MRI |
| medicine have a typical magnetic field | | | | scanner. |
| strength of 0.2 to 3 Teslas. | | | | |
| | | | B. Patients who have heart pacemakers, metal |
| An MRI (or magnetic resonance imaging) scan | | | | implants, or metal chips or clips in or |
| is a radiology technique that uses magnetism, | | | | around the eyeballs cannot be scanned with an |
| radio waves, and a computer to produce images | | | | MRI because of the risk that the magnet may |
| of body structures. The MRI scanner is a tube | | | | move the metal in these areas. |
| surrounded by a giant circular magnet. The | | | | |
| patient is placed on a moveable bed that is | | | | C. Similarly, patients with artificial heart |
| inserted into the magnet. The magnet creates | | | | valves, metallic ear implants, bullet |
| a strong magnetic field that aligns the | | | | fragments, and chemotherapy or insulin pumps |
| protons of hydrogen atoms, which are then | | | | should not have MRI scanning. |
| exposed to a beam of radio waves. This spins | | | | |
| the various protons of the body, and they | | | | During the MRI scan, patients lie in a closed |
| produce a faint signal that is detected by | | | | area inside the magnetic tube. Some patients |
| the receiver portion of the MRI scanner. The | | | | can experience a claustrophobic sensation |
| receiver information is processed by a | | | | during the procedure. |
| computer, and an image is produced. The image | | | | |
| and resolution produced by MRI is quite | | | | D. Therefore, patients with any history of |
| detailed and can detect tiny changes of | | | | claustrophobia should make known this |
| structures within the body. For some | | | | condition to the medical practitioner who is |
| procedures, contrast agents, such as | | | | requesting the test, as well as the |
| gadolinium, are used to increase the accuracy | | | | radiological staff at the center when the |
| of the images. | | | | scan is being performed. |
| | | | |
| What are some uses of MRI? | | | | E. The staff at the center can administer a |
| | | | mild sedative prior to the MRI scan to help |
| MRI is primarily used in medical imaging to | | | | alleviate any feelings of claustrophobia. |
| demonstrate pathological or other | | | | |
| physiological alterations of living tissues. | | | | F. It is normal and expected that the MRI |
| MRI also has uses outside of the medical | | | | staff will remain during MRI scan. |
| field, such as detecting rock permeability to | | | | Furthermore, there is usually a means of |
| hydrocarbons and as a non-destructive testing | | | | communication with the staff in the form of a |
| method to characterize the quality of | | | | buzzer held by the patient which can be used |
| products such as produce and timber. | | | | for contact if the patient cannot tolerate |
| | | | the scan. |
| An MRI scan can be used as an extremely | | | | |
| accurate method of disease detection | | | | What happens after the scan? |
| throughout the body. In the head, trauma to | | | | |
| the brain can be seen as bleeding or | | | | After the MRI scanning is completed, the |
| swelling. Other abnormalities often found | | | | computer generates visual images of the area |
| include brain aneurysms, stroke, tumors of | | | | of the body that was scanned. These images |
| the brain, as well as tumors or inflammation | | | | can be transferred to film (hard copy). A |
| of the spine. Neurosurgeons use an MRI scan | | | | radiologist then interprets the images of the |
| not only in defining brain anatomy but in | | | | body and the interpretation is transmitted to |
| evaluating the integrity of the spinal cord | | | | the practitioner who originally requested the |
| after trauma. It is also used when | | | | MRI scan. At this point the practitioner can |
| considering problems associated with the | | | | then discuss the results with the appropriate |
| vertebrae or intervertebral discs of the | | | | individuals. |
| spine. An MRI scan can evaluate the structure | | | | |
| of the heart and aorta, where it can detect | | | | The Future of MRI technology! |
| aneurysms or tears. It provides valuable | | | | |
| information on glands and organs within the | | | | Scientists are developing newer MRI scanners |
| abdomen, and accurate information about the | | | | that are smaller and more portable. These new |
| structure of the joints, soft tissues, and | | | | scanners can be most useful in detecting |
| bones of the body. Often, surgery can be | | | | infections and tumors of the soft tissues of |
| deferred or more accurately directed after | | | | the hands, feet, elbows, and knees. The |
| knowing the results of an MRI scan. | | | | functionality and application of these |
| | | | scanners to medical practice is currently |
| What are the risks of an MRI scan? | | | | being researched and tested. |
| | | | |