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Role of MRI - What to Expect |
MRI, a totally different way of "seeing" inside the body
MRI, or magnetic resonance imaging, is a dynamic way for doctors to diagnose certain diseases. MRI doesn't rely on x-rays. Instead it uses a magnetic field and radio waves to create a very clear picture of internal body structures. MRI uses sensitive instruments and specially designed computers to create images of the entire area being scanned. This exciting technology provides information to help you and your doctor make better decisions about your medical care.
What does MRI see?
MRI has become a preferred method for diagnosing potential problems in many different parts of the body. While x-rays are best for showing bones, MRI creates pictures that can show differences between healthy and unhealthy tissue. Doctors use MRI to examine soft tissue like organs, muscle, cartilage, ligaments, and tendons in many parts of the body. That means MRI is helpful when looking at the brain, spinal column, breast, abdomen, pelvic region, and joints like your knee and elbow.
You won't feel anything
Having an MRI doesn't hurt during the scan or afterwards. Millions of patients have had MRIs and the procedure has proved extremely safe.
What do you need to do before your MRI?
There's no special preparation necessary before having an MRI exam. Unless your doctor specifically requests that you not eat or drink anything before the exam, there are no restrictions on food. You won't be allowed to wear anything metallic during the exam, so it would be best to leave watches, jewelry or anything else containing metal at home. Even some cosmetics contain metals; so don't wear make-up when you go to the MRI center.
When you leave for your MRI exam, be sure to have your insurance forms and your doctor's prescription for the MRI exam with you. That will help reduce the time spent on paperwork while you are at the center.
People of all ages, from very young children to very elderly people, have had MRI examinations. Because of the strong magnetic field and radio frequencies, people who have a heart pacemaker or any kind of metallic implant in their body shouldn't have an MRI unless their physician knows about the metallic appliance and has approved the MRI exam. You should also be sure that the MRI center knows about any metal fragments that may remain in your body from an old accident or war wound.
What is the MRI procedure like?
The examination itself is performed in a room that houses the MRI equipment. You'll be asked to lie down on a comfortably padded table that gently glides you into the magnet. While the scanner is operating, you'll hear some humming and occasional thumping sounds. These are normal and shouldn't worry you. In some cases, your doctor may have requested that you receive an injection of a contrast agent to give a clearer picture of the area being examined.
The most important thing for you to do is to relax and lie still. Most exams take between 30 and 45 minutes, although some may take as long as 60 minutes. You'll be told ahead of time just how long your scan is expected to take.
When will you know results?
Once your MRI exam is completed, the pictures will be looked at by a radiologist, a specially trained physician who is able to interpret the scans for your doctor. The radiologist will send your doctor a written report. You should contact your physician within a day or two of your scan to make an appointment to go over your results and discuss your next step.
The exact relationship between MRI findings and the clinical status of patients is not completely understood.
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INDICATIONS and IMPORTANT SAFETY INFORMATION
MAGNEVIST® (gadopentetate dimeglumine) Injection
INDICATIONS AND USAGE
Central Nervous System: MAGNEVIST® (gadopentetate dimeglumine) Injection is indicated for use with magnetic resonance imaging (MRI) in adults, and pediatric patients (2 years of age and older) to visualize lesions with abnormal vascularity in the brain (intracranial lesions), spine and associated tissues. MAGNEVIST Injection has been shown to facilitate visualization of intracranial lesions including but not limited to tumors.
Extracranial/Extraspinal Tissues: MAGNEVIST is indicated for use with MRI in adults and pediatric patients (2 years of age and older) to facilitate the visualization of lesions with abnormal vascularity in the head and neck.
Body: MAGNEVIST Injection is indicated for use in MRI in adults and pediatric patients (2 years of age and older) to facilitate the visualization of lesions with abnormal vascularity in the body (excluding the heart).
IMPORTANT SAFETY INFORMATION
WARNING: NEPHROGENIC SYSTEMIC FIBROSIS
Gadolinium-based contrast agents increase the risk for nephrogenic systemic fibrosis (NSF) in patients with:
- acute or chronic severe renal insufficiency (glomerular filtration rate < 30 mL/min/1.73m2), or
- acute renal insufficiency of any severity due to the hepato-renal syndrome or in the perioperative liver transplantation period.
In these patients, avoid use of gadolinium-based contrast agents unless the diagnostic information is essential and not available with non-contrast enhanced magnetic resonance imaging (MRI). NSF may result in fatal or debilitating systemic fibrosis affecting the skin, muscle and internal organs. Screen all patients for renal dysfunction by obtaining a history and/or laboratory tests. When administering a gadolinium-based contrast agent, do not exceed the recommended dose and allow a sufficient period of time for elimination of the agent from the body prior to any readministration.
The possibility of serious or life-threatening anaphylactic or anaphylactoid reactions, including cardiovascular, respiratory, and/or cutaneous manifestations, should always be considered. As with other paramagnetic contrast agents, caution should be exercised in patients with renal insufficiency due to the possibility of further deterioration in renal function. As with other injectable products, cases of phlebitis and thrombophlebitis have been reported; assessment of the dosed limb for the development of injection site reactions is recommended.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.
For important risk and use information, please see the full prescribing information.
EOVIST® (gadoxetate disodium) Injection
INDICATIONS AND USAGE
EOVIST® (gadoxetate disodium) Injection is a gadolinium-based contrast agent indicated for intravenous use in T1-weighted magnetic resonance imaging (MRI) of the liver to detect and characterize lesions in adults with known or suspected focal liver disease.
IMPORTANT SAFETY INFORMATION
WARNING: NEPHROGENIC SYSTEMIC FIBROSIS
Gadolinium-based contrast agents increase the risk for nephrogenic systemic fibrosis (NSF) in patients with:
- acute or chronic severe renal insufficiency (glomerular filtration rate < 30 mL/min/1.73m2), or
- acute renal insufficiency of any severity due to the hepato-renal syndrome or in the perioperative liver transplantation period.
In these patients, avoid use of gadolinium-based contrast agents unless the diagnostic information is essential and not available with non-contrast enhanced magnetic resonance imaging (MRI). NSF may result in fatal or debilitating systemic fibrosis affecting the skin, muscle and internal organs. Screen all patients for renal dysfunction by obtaining a history and/or laboratory tests. When administering a gadolinium-based contrast agent, do not exceed the recommended dose and allow a sufficient period of time for elimination of the agent from the body prior to any readministration.
The possibility of serious or life-threatening anaphylactoid/hypersensitivity reactions with cardiovascular, respiratory and/or cutaneous manifestations should always be considered. The most common adverse reactions observed in clinical trials at the recommended dose included feeling hot, nausea and headache.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.
For important risk and use information, please see the full prescribing information.
ULTRAVIST® (iopromide) Injection
INDICATIONS AND USAGE
ULTRAVIST® (iopromide) Injection is an iodinated contrast agent indicated for:
Intra-arterial Procedures*: 150 mgI/mL for intra-arterial digital subtraction angiography (IA-DSA); 300 mgI/mL for cerebral arteriography and peripheral arteriography; 370 mgI/mL for coronary arteriography and left ventriculography, visceral angiography, and aortography.
Intravenous Procedures*: 240 mgI/mL for peripheral venography; 300 mgI/mL for excretory urography; 300 mgI/mL and 370 mgI/mL for contrast Computed Tomography (CT) of the head and body (intrathoracic, intra-abdominal and retroperitoneal regions) for the evaluation of neoplastic and non-neoplastic lesions. The usefulness of contrast enhancement for the investigation of the retrobulbar space and of low grade or infiltrative glioma has not been demonstrated.
*For information on the concentrations and doses for the Pediatric Population [see Dosage and Administration (2.3) and Use in Specific Populations (8.4) in the full prescribing information].
IMPORTANT SAFETY INFORMATION
WARNING: NOT FOR INTRATHECAL USE
Inadvertent intrathecal administration may cause death, convulsions, cerebral hemorrhage, coma, paralysis, arachnoiditis, acute renal failure, cardiac arrest, seizures, rhabdomyolysis, hyperthermia, and brain edema.
CONTRAINDICATIONS
ULTRAVIST Injection is contraindicated for intrathecal use.
Preparatory dehydration (e.g. prolonged fasting and the administration of a laxative before ULTRAVIST Injection) is contraindicated in pediatric patients because of risk of renal failure.
WARNINGS AND PRECAUTIONS
Life-threatening or fatal anaphylactoid reactions may occur during or after Ultravist administration. Acute renal failure may occur following ULTRAVIST administration, particularly in patients with renal insufficiency, diabetes, multiple myeloma. Hemodynamic disturbances including shock and cardiac arrest may occur during or shortly after administration of ULTRAVIST. Angiography may be associated with local and distal organ damage, ischemia, thromboembolism and organ failure.
MOST COMMON ADVERSE REACTIONS
Most common adverse reactions (>1%) are headache, dysguesia, abnormal vision, chest pain, vasodilatation, nausea, vomiting, back pain, urinary urgency, injection site and infusion site reactions, and pain.
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.
For important risk and use information, please see the full prescribing information.
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