Topic Contents What is it? Why is this test done? How do you prepare for the test? What happens during the test? How long does the test take? How does having an MRI of the head feel? What are the risks of an MRI of the head? What happens after the test? Where can you learn more? Top of the page. What is it? You may have contrast material dye put into your arm through a tube called an IV.
You will lie on a table that's part of the MRI scanner. The table will slide into the space that contains the magnet. Inside the scanner, you will hear a fan and feel air moving. You may hear tapping, thumping, or snapping noises. You may be given earplugs or headphones to reduce the noise. You will be asked to hold still during the scan.
You may be alone in the scanning room. But a technologist will watch through a window and talk with you during the test. In rare cases, you may feel: Warmth in the area being checked.
This is normal. Tell the technologist if you have nausea, vomiting, a headache, dizziness, pain, burning, or breathing problems.
If there is going to be any immediate reaction such as those mentioned above , it will almost always be apparent within a few minutes; that is, before the end of the scan.
Gadolinium contrast medium is generally very safe. Side effects or reactions are uncommon, but can occur. The most common adverse reactions are minimal: headache, nausea feeling slightly sick and dizziness for a brief time after the injection. A few patients will have a feeling of coldness at the injection site. Less often, in approximately 1 in patients, an itchy skin rash might appear a few minutes after the injection.
This appears to be due to a mild allergy. It usually settles down by itself within an hour or so, but rarely it might be a warning sign of a more serious allergic reaction developing. Severe allergic anaphylactic reactions to gadolinium contrast medium have occurred, but are extremely rare. These severe reactions, which might involve difficulty breathing and swelling of the lips and mouth, occur in approximately 1 in every 10, people who have gadolinium.
These severe reactions generally respond very well to standard emergency drug treatment, similar to that given for other severe allergic reactions. These are usually medications that will be given through the tube that was placed in your arm before or during the MRI scan. All radiology facilities where gadolinium injections are given maintain stock of the medications required to treat these reactions, and are equipped to administer them when needed.
Nephrogenic systemic fibrosis NSF is a rare debilitating disease resulting in skin contractures or localised skin thickening and tightening and internal organ damage. It has occurred with some gadolinium-based contrast media in a minority of patients with pre-existing severe kidney function abnormalities. There are some forms of gadolinium contrast for which there seem to be lower risks of NSF than for others, and these low-risk forms are used in patients with less severe renal disease if the likely benefit better diagnosis justifies the very low likelihood of subsequent NSF.
Even in those with end-stage kidney disease, the risk of NSF developing after a single injection of a lower risk agent is believed to be well under 1 in injections. For this reason, you will be asked questions about possible kidney disease as part of the safety screening before the MRI scan. If you have kidney disease, please advise your referring doctor before the procedure, so that you, your doctor and the MRI radiologist can discuss whether or not the possible benefits of a gadolinium injection outweigh the possible risks in your case.
This seems to be more likely with the same forms of gadolinium contrast that have a higher risk for NSF. At this stage, there are no known adverse effects from these very small amounts of retained gadolinium. This finding has made radiologists more careful to recommend gadolinium contrast only where it is likely to assist the diagnosis. If you are pregnant, or think you might be pregnant, please inform your doctor or radiologist before having the procedure, so that your doctor can consider and talk to you about any risks and benefits of having an MRI scan, and a possible gadolinium injection, for you and your unborn baby.
Where relevant, you will be asked about the possibility of pregnancy as part of the safety screening before any MRI scan. If you are pregnant or possibly pregnant, it is unlikely that you will have a gadolinium injection unless it is absolutely essential. If an injection is recommended, this would be discussed with you and your doctor before giving you the injection.
If you are breast-feeding, it is safe to continue normal breast-feeding after the gadolinium contrast medium has been given.
There is no requirement to express and dispose of breast milk or to withhold breast-feeding. Although the gadolinium is eliminated from the body through the kidneys, if you are breast-feeding, it has been shown that a tiny part less than 1 part in of the injected gadolinium can enter the breast milk. The amount received by your baby is so small it is not thought to represent any danger to your child. Gadolinium MRI contrast injections improve diagnostic accuracy in some conditions, such as inflammatory and infectious diseases of the brain, spine, soft tissues and bones, by making images clearer so that the radiologist can better see what and where the problem is.
Radio waves make these protons create very faint signals—and those are used to make cross-sectional images. Those images are layered on top of each other to give radiologists a really good view of the inside of your body that they can see from different angles.
Healthcare providers will often turn to an MRI when they suspect you have an injury or illness that an X-ray, CT scan, or ultrasound is not able to capture. There is typically very little pre-appointment prep that you will need prior to your MRI. In most instances, you will arrive at your appointment to have your MRI without any specific prep. The most important thing to ensure prior to having an MRI is that you do not have any metal on or in your body. The machine is a very strong magnet, and metals can cause problems.
Gadolinium lights up when you get a scan and can help radiologists get a better look at your brain, heart, and blood vessels. This can aid them in making a diagnosis of cancer or an inflammatory condition like multiple sclerosis. The machine will typically be long and tube-shaped with one or two open ends.
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