in a New Era for Radiology Imaging
photo of a MR image made
with the new Toshiba MR
shows the latest in Non-Contrast
Imaging -- as this image
was made without injecting
any contrast media dye.
The new MR has the latest
in Noise Reduction Technology that significantly reduces
exam noise. And this means
KDMC patients will receive
the quietest MR available.
"The Toshiba Titan
MR is a dramatic improvement
over other traditional MR
systems, as it offers the
largest and widest bore
available with a significant
reduction in noise,"
says Kelly Smith, KDMC Radiology
MRI - Magnetic Resonance Imaging MRI (magnetic resonance imaging) is a diagnostic tool that examines tissue water and fat. Unlike x-ray based techniques, MRI uses a magnet and radio waves to produce images of normal and pathologic tissues. The technique has proven very valuable for the diagnosis of a broad range of conditions in all parts of the body. MRI is being used to evaluate cancer, heart and vascular disease, stroke, joint, and musculoskeletal disorders.
MRI requires specialized equipment and expertise and allows evaluation of some body parts that may not be as visible with other radiology procedures. MRI is a relatively safe imaging technique; however, it is not for all patients. The MRI staff carefully screens all patients prior to entry inside the MRI work area. Patients who have these situations may not be candidates for MRI:
heart pace makers
heart pacing wires
implanted tens units
implanted metal plates
Some tattoos and permanent eyeliner may cause discomfort. Most other surgical pins, screws, rods, artificial heart valves and vascular stents that have been in place six-eight weeks are okay. Dental work, braces, or other metal close to the area of interest will cause image artifacts. Any object that might degrade the MRI images will have to be removed (such as hairpins, jewelry, medication patches, eyeglasses, hearing aids, and any removable dental work).
What to Expect
The MRI staff will ask about drug allergies and document a medical/surgical history. If there is a chance of pregnancy, the MRI technologist should be informed. Some patients may require a mild sedative to overcome claustrophobic feeling. This should be obtained from the referring physician prior to arrival. If sedatives are used, the patient will need someone to drive them home. Please ask the staff any questions that you may have.
How does MRI work?
MRI is a unique imaging method because, unlike the usual X-Ray, Nuclear Medicine, and even CT scanning, it does not rely on ionizing radiation. Instead radio waves are directed at protons, the nuclei of hydrogen atoms, in a strong magnetic field. The protons are first excited and then relaxed emitting radio signals, which can be computer processed to form an image. In the body, protons are most abundant in the hydrogen atoms of water - the "H" of H 2 O -- so that an MRI image shows the differences in the water content in body organs or tissues (even different types of tissue within the same organ). For example the gray and white matter of the brain can easily be distinguished with MRI. Each MRI procedure has its own protocol which demonstrates contrast differences and shows a cross-section image of the body part.
How is the MRI exam performed?
The technologist will complete a medical history form and answer any questions. The patient will lie on a sliding table and be positioned comfortably usually on their back. Patients are offered earplugs to reduce the loud tapping or knocking noise during the imaging phases. If indicated IV contrast is injected via small needle in a vein in the hand or lower arm. MRI equipment (coil) is place near the body part or region of interest. The MRI table will slide into the bore or opening in the magnet. The patient will be able to communicate with the technologist by intercom. It is important that the patient follow any instructions and lie still during the imaging phase. Typically, most procedures last 30 to 45 minutes depending on the number of images needed. Patient must bring a list of all medications.
The most common uses of MRI Imaging:
Detecting brain and other tumors of the head and neck
Locating brain damage or bleeding within the brain
Cause of hearing or vertigo problems
Evaluation of carotid arteries, heart, aorta, and other blood vessels in the abdomen and lower legs
Evaluation of arterial aneurysm
Diagnosing disease of the kidneys, liver, spleen and pancreas
Spinal and joint problems (arthritis/herniated disc)
Sport related injuries
Evaluation of infection or metastatic process of bone and joints
What are the Benefits VS Risks?
Benefits: Images of the soft-tissue structures of the body - such as the brain, heart, lungs, liver and other organs--are clearer and more detailed than with other imaging methods
MRI images can help physicians evaluate the function as well as the structure of many organs
The detail of MRI images makes MRI an invaluable tool in early diagnosis and evaluation of tumors
MRI contrast material is less likely to produce an allergic reaction than the iodine based materials used for conventional x-rays and CT scanning
MRI enables the detection of abnormalities that might be obscured by bone with other imaging tools
MRI provides a fast, noninvasive, alternative to x-ray angiography for diagnosing problems of the heart and cardiovascular system
Exposure to radiation is avoided
Risks: Patients with a pacemaker can not enter the strong magnetic field
Other implanted metal devices may be affected by the strong magnetic field. Examples heart stents, pacing wires, implanted defibrillators, cochlear implants, and artificial heart valves
MRI is generally avoided in the first 12 weeks of pregnancy. Doctors usually use other methods of imaging, such as ultrasound, unless there is a strong medical reason
Picture Archival & Communication System (PACS) - This technology allows images to be electronically captured, stored and transmitted--all without film. PACS makes high-quality MRI, CT, X-ray and ultrasound pictures immediately available by computer. Patients no longer need to carry X-rays from place to place. In addition, PACS gives such clear images that doctors believe it results in a better, more accurate diagnosis.