We offer more than physicians and 20 locations throughout Chicago, ensuring complete musculoskeletal care wherever our patients are. Contact us to learn more about our advanced diagnostic technology and services. Uses and Advantages Physicians order contrast MRIs for their patients because they do a better job of showing clear images for certain conditions.
How to Prepare Unless your doctor tells you otherwise, eat normally and keep taking your medications before your contrast MRI exam. Related Posts. December 21, May 4, March 16, October 31, Allergic reactions will tend to occur right away. Serious reactions may require emergency treatment including medication. Fatal reactions to gadolinium can occur but are extremely rare. If you have not had a recent blood test to check your kidney function, a finger stick blood test may be done just prior to your MRI exam.
With normal kidney function, most of the gadolinium is removed from your body in the urine within 24 hours. If you have acute renal failure or severe chronic kidney disease and receive a gadolinium-based contrast agent, there may be a very small risk of developing a rare condition. Due to the detail seen on an MRI, the contrast is not needed to diagnose most diseases or injuries.
However, in some cases, contrast is used to help in the diagnostic process. MRI contrast is an injectable dye used to highlight certain areas and give a more definitive diagnosis. MRI contrast is called gadolinium. Imaging exams such as x-rays , ultrasound , computed tomography CT , magnetic resonance MRI , and fluoroscopy are selected based on their ability to show specific information about the structures within the body.
Contrast materials, also known as contrast agents and contrast media are used to improve the diagnostic value of those imaging exams.
Contrast materials are not dyes that permanently discolor internal organs. They are substances that temporarily change the way x-rays or other imaging tools interact with the body. The materials discussed in this article do not produce radiation. When introduced into the body prior to an imaging exam, contrast materials make certain structures or tissues in the body appear different on the images than they would if no contrast material had been administered.
Contrast materials help distinguish or "contrast" selected areas of the body from surrounding tissue. This helps physicians diagnose medical conditions by improving the visibility of specific organs, blood vessels, or tissues. Following an imaging exam with contrast material, the material is absorbed by the body or eliminated through urine or bowel movements. Contrast materials can have a chemical structure that includes iodine, a naturally occurring chemical element.
These contrast materials can be injected into veins or arteries, within the disks or the fluid spaces of the spine, and into other body cavities. Barium-sulfate is the most common contrast material taken by mouth, or orally.
It is also used rectally and is available in several forms, including:. When iodine-based and barium-sulfate contrast materials are present in a specific area of the body, they block or limit the ability of x-rays to pass through. As a result, blood vessels, organs and other body tissue that temporarily contain the iodine-based or barium compounds change their appearance on x-ray or CT images.
Barium-sulfate contrast materials that are swallowed or administered by mouth orally are used to enhance standard x-ray, fluoroscopy, and CT images of the gastrointestinal GI tract, including:.
In some situations, iodine-based contrast materials are substituted for barium-sulfate contrast materials for oral administration. Barium-sulfate contrast materials that are administered by enema rectally are used to enhance standard x-ray, fluoroscopy, and CT images of the lower gastrointestinal GI tract colon and rectum.
In some situations, iodine-based contrast materials are substituted for barium-sulfate contrast materials for rectal administration.. Iodine-based contrast materials injected into a vein intravenously are used to enhance x-ray including fluoroscopic images and CT images. Gadolinium injected into a vein intravenously is used to enhance MR images. Typically, these are used to enhance:.
Microbubble contrast materials are tiny bubbles of an injectable gas held in a supporting shell. They are extremely small—smaller than a red blood cell—and have a high degree of "echogenicity", or ability to reflect ultrasound waves.
Structures with higher echogenicity will appear brighter on ultrasound. Once the microbubbles are in the bloodstream, ultrasound technology is able capture differences in echogenicity between the gas in the microbubbles and the surrounding tissues of the body, producing an ultrasound image with increased contrast.
The microbubbles dissolve, usually within 10 to 15 minutes, and the gas within them is removed from the body through exhalation. Contrast-enhanced ultrasound with microbubbles is a convenient, relatively inexpensive way to improve visualization of blood flow, and it does not use radiation. Microbubble contrast materials can be targeted or untargeted. Untargeted contrast-enhanced ultrasound —the more common method— helps diagnose certain diseases by providing evaluation of blood flow in the heart and other organs.
In targeted contrast-enhanced ultrasound, specific molecules are bound to the surface of the microbubbles. After injection, the microbubbles attach to specific targeted tissue sites, causing an increase in the ultrasound signal at the sites. Contrast materials are safe drugs; adverse reactions ranging from mild to severe do occur, but severe reactions are very uncommon.
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