You might have metal in your body if you have a shrapnel or bullet injury or if you are a welder. Have metal or electronic devices in your body, such as a cardiac pacemaker or a metal artificial joint. Start Here. Related Issues.
Videos and Tutorials. Statistics and Research. In some cases, you may be asked to get back into the MRI scanner so that more pictures can be taken.
If the pictures are satisfactory, you can get dressed and go home. There are no known long-term side effects from undergoing MRI. The MRI scan does not use ionising radiation to achieve its pictures. Be guided by your doctor but, generally, there are no special after-care instructions. A radiologist and other specialised doctors will examine and interpret the scan images. You will need to make an appointment with your doctor to discuss the results.
The MRI scan will help the doctor to plan appropriate treatment, if necessary. The MRI scanner is a complicated piece of equipment that is expensive to use and found only in specialised centres. Alternatives to MRI depend on the medical condition under investigation, but could include:.
This page has been produced in consultation with and approved by:. The long-term effects of brain injury will be different for each person and can range from mild to profound.
A person with alcohol related brain impairment ARBI might experience problems with coordination, thinking, planning and memory. If a person with alcohol related brain impairment is aware of their memory limits, they can learn how to deal with them. People with alcohol related brain impairment benefit when their life is organised and follows a good structure. Allergy testing is used to find which substances provoke an allergic reaction. Content on this website is provided for information purposes only.
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When your body is placed in the magnetic field, these atoms align with the field, much like a compass points to the North Pole. A radio wave "knocks down" the atoms and disrupts their polarity. The sensor detects the time it takes for the atoms to return to their original alignment. In essence, MRI measures the water content or fluid characteristics of different tissues, which is processed by the computer to create a black and white image.
The image is highly detailed and can show even the smallest abnormality. Similar to CT, MRI allows your doctor to see your body in narrow slices, each about one quarter of an inch thick. For example, imagine that you are slicing a loaf of bread and taking a picture of each slice.
It can view slices from the bottom axial , front coronal , or sides sagittal , depending on what your doctor needs to see. A dye contrast agent may be injected into your bloodstream to enhance certain tissues.
The dye contains gadolinium, which has magnetic properties. It circulates through the blood stream and is absorbed in certain tissues, which then stand out on the scan.
MR angiogram MRA. MRI can be used to view arteries and veins. Contrast dye gadolinium injected into the bloodstream helps the computer "see" the arteries and veins. Contrast is also used to view tumors and arteriovenous malformations AVMs. Nearly every part of the body may be studied with MRI.
MRI gives very detailed pictures of soft tissues like the brain. Air and hard bone do not give an MRI signal so these areas appear black. Bone marrow, spinal fluid, blood and soft tissues vary in intensity from black to white, depending on the amount of fat and water present in each tissue and the machine settings used for the scan.
Brian Shapiro, M. Vivien Williams: Dr. Brian Shapiro uses MRI to look for abnormalities in the heart. So, swelling of the heart is a very common thing in heart attacks, and infections, and things like that. Shapiro how well the heart pumps, where irregular heart beats originate, the location of blood clots, artery blockages, scar tissue, or even tumors. Because MRI allows doctors to see more detail of the heart, they can make more accurate diagnoses, and therefore tailor treatment for patients.
Vivien Williams: Images that tell Dr. Shapiro if a patient will recover, if there's permanent damage, and what treatments might be best. Information from inside the heart that can help Dr. Shapiro and his colleagues better help their patients. Shapiro says while MRI can show lots of information about the heart, it does not replace other tests such as stress tests or echo cardiograms. It's another option for looking inside the heart. Explore Mayo Clinic studies of tests and procedures to help prevent, detect, treat or manage conditions.
Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version. Brain tumor MRI Brain tumor imaging. Request an Appointment at Mayo Clinic. MRI technician: You can breathe. Breathe normal. Vivien Williams: The moving or still images show exactly where damage happens. Share on: Facebook Twitter. Show references Neurological diagnostic tests and procedures fact sheet.
National Institute of Neurological Disorders and Stroke. Accessed July 20, Magnetic resonance imaging MRI safety. Chernoff D, et al. Principles of magnetic resonance imaging. Tsai LL. Patient evaluation for metallic or electrical implants, devices or foreign bodies before magnetic resonance imaging.
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