Mri what can it show

Before an MRI exam, eat normally and continue to take your usual medications, unless otherwise instructed. You will typically be asked to change into a gown and to remove things that might affect the magnetic imaging, such as:.

The MRI machine looks like a long narrow tube that has both ends open. You lie down on a movable table that slides into the opening of the tube. A technologist monitors you from another room. You can talk with the person by microphone. If you have a fear of enclosed spaces claustrophobia , you might be given a drug to help you feel sleepy and less anxious.

Most people get through the exam without difficulty. The MRI machine creates a strong magnetic field around you, and radio waves are directed at your body. The procedure is painless. You don't feel the magnetic field or radio waves, and there are no moving parts around you. During the MRI scan, the internal part of the magnet produces repetitive tapping, thumping and other noises. You might be given earplugs or have music playing to help block the noise.

In some cases, a contrast material, typically gadolinium, will be injected through an intravenous IV line into a vein in your hand or arm. The contrast material enhances certain details. Gadolinium rarely causes allergic reactions. An MRI can last anywhere from 15 minutes to more than an hour.

You must hold still because movement can blur the resulting images. During a functional MRI , you might be asked to perform a number of small tasks — such as tapping your thumb against your fingers, rubbing a block of sandpaper or answering simple questions. This helps pinpoint the portions of your brain that control these actions.

A doctor specially trained to interpret MRI s radiologist will analyze the images from your scan and report the findings to your doctor. Your doctor will discuss important findings and next steps with you. An MRI is a very useful tool for helping your doctors see images of the inside of your body, including tissue that can't be seen on a conventional x-ray. Before your exam, it's very important to fill out the safety screening form carefully. MRI is safe and painless. But metal in the scanner can cause serious safety problems or reduce the quality of the images.

Your health care team needs to know about any metal in your body, even a small shard of metal from an accident. Fillings, bridges, and other dental work typically do not pose a problem.

But other metal that has been put into your body might prevent you from having an MRI. That includes some pacemakers, clips for treating aneurysms, and other devices with metal in them. A nurse may review your health history before your exam. It uses a magnetic field and radio waves to take pictures inside the body. Normal x-rays image calcium, so they are good to see bones. MRI scans image water, which makes them very useful because all tissues of the body contain various amounts of water.

This allows high-resolution pictures of many organs and tissues to be taken that are invisible to standard x-rays. The MRI scan consists of a table that slides into a large cylinder. Inside the cylinder is a magnet that, when operated, creates a powerful magnetic field. Soft tissue contains water molecules and the magnetic field acts upon microscopic substances called protons found in water.

A computer then organises these echoes into images. The MRI scan is used to investigate or diagnose conditions that affect soft tissue, such as:. The MRI scan provides clear and detailed images of soft tissue. That is why bone injury or disease is usually investigated with regular x-ray examinations rather than MRI scanning.

You may be asked to wait while the radiographer checks the quality of the pictures. 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. Patients are placed on a table that slides into the tunnel. Some centers have open MRI machines that have larger openings and are helpful for patients with claustrophobia. MRI machines are located in hospitals and radiology centers.

During the exam, radio waves manipulate the magnetic position of the atoms of the body, which are picked up by a powerful antenna and sent to a computer. The computer performs millions of calculations, resulting in clear, cross-sectional black and white images of the body. These images can be converted into three-dimensional 3-D pictures of the scanned area.

This helps pinpoint problems in the brain and the brain stem when the scan focuses on those areas. MRI can detect a variety of conditions of the brain such as cysts, tumors, bleeding, swelling, developmental and structural abnormalities, infections, inflammatory conditions, or problems with the blood vessels.

It can determine if a shunt is working and detect damage to the brain caused by an injury or a stroke. MRI of the brain can be useful in evaluating problems such as persistent headaches, dizziness, weakness, and blurry vision or seizures, and it can help to detect certain chronic diseases of the nervous system, such as multiple sclerosis. In some cases, MRI can provide clear images of parts of the brain that can't be seen as well with an X-ray, CAT scan, or ultrasound, making it particularly valuable for diagnosing problems with the pituitary gland and brain stem.

In many cases, a brain MRI requires no special preparation. However, the technician will have your child remove any objects containing metal such as eyeglasses and jewelry because they can produce a bright or blank spot on the diagnostic film. You'll also be asked questions to make sure your child doesn't have any internal metal clips from previous surgery or anything else that might cause a problem near a strong magnetic field.

Electronic devices aren't permitted in the MRI room. To get the highest quality MRI results, your child will need to lie still during the scan. For this reason, sedation may be needed, especially for babies and young kids, who often have trouble staying still for the test. Additionally, if you have metal inside your body, you may not be able to have an MRI. Discuss this with your doctor before scheduling an MRI if you are pregnant or breastfeeding, or if you have:.

MRIs are painless. Any movement could result in blurred images, just as they would with a typical camera. The amount of time for the scan will vary, depending on what you are having scanned. Normally, scans last between 15 minutes to an hour. The MRI machine itself looks like a big donut with a table attached to it. Your whole body does not go in the machine, only the half or part that needs to be scanned.

It makes a lot of different noises, and some of them are extremely loud. Some patients say it sounds like a sledgehammer. For this reason, you will be offered headphones. You can listen to music or sometimes even watch a movie. Pressing the button will signal the technician that you would like to stop the scan and come out of the machine. Some doctors may prescribe a one-time, low-dose anti-anxiety medicine to relax you for the test.

This person also will not be allowed to wear jewelry or metal and will have to go through the same screening process as the person being scanned. A radiologist a doctor who specializes in medical imaging will review the images and send a report to your referring doctor. Your doctor will receive a full report a day or two following the test and can go over the results with you.

Even though having an MRI is safe and painless, it can be a difficult test for persons who are claustrophobic. The MRI machine is never completely closed, but just being even partially in an enclosed area is enough to fill some people with dread. Open MRI machines are, as the name suggests, more open and less confining than the traditional machines. They have larger openings and do not completely surround your body.

This makes them a better alternative not only for claustrophobic patients, but also for obese patients or normal-sized males who have larger shoulders. Small children who are incapable are being still for the duration of the scan may require sedation prior to having an MRI. In this case, an anesthesiologist would provide the sedation and stay in addition to a nurse to monitor the patient before, during, and after the scan.

Sedation is also sometimes used for patients who are extremely claustrophobic. If your MRI requires contrast, your radiologist will monitor you for allergies during the procedure. Severe reactions to the contrast agent are rare, but could happen. In those cases, the radiology department is well-trained on how to handle your allergic reaction.