Need an MRI? Read This!

Posted by Wei Mai on December 12th, 2019

MRI, or Magnetic Resonance Imaging, is a technique used in the medical field to image the inner structures of your body, much like an x-ray or a CT (Computed Tomography) Scan. So what sets MRI apart from these other techniques?

A lot of what makes an MRI different from other imaging techniques is the way that it works. An x-ray essentially takes photographs in two-dimensions of your body, and a CT Scan can take pictures of the bone and soft tissue using radiation in a similar fashion to x-rays. MRI's on the other hand, do not use radiation to take pictures of your body. This minimizes radiation exposure, which is ideal for young patients, people who need multiple images, or when a detailed view of the soft tissues (ligaments, muscles, and cartilage, for example) is required.

How Does It Work?

The way MRI's work is by utilizing the water in your body. Our bodies are made up of about 75% water, which is chemically known as H2O. By placing a human body into a large magnet, we are able to align the abundant hydrogen atoms into a single direction. We can the use a radio frequency to excite these hydrogen atoms, and measure the amount of excitation and the time required for them to relax. Different tissue types in the body will have different times required for excitation/relaxation, which is the basis of MRI imaging.

The signals given off by the hydrogen atoms in the body are then converted to an image, which helps your doctor understand what is happening to the tissues in your body. This technique is especially useful in imaging things like ligaments and tendons, which can be difficult to evaluate on an x-ray image.

For further explanation, you may want to watch this video at YouTube.

Is MRI Safe?

Yes. MRI's are generally a safe procedure. They produce no radiation, which is a concern for x-ray and CT scan imaging techniques.

Some safety precautions required for MRI procedures include removing any metal from your clothing and body before entering the MRI room. Because an MRI machine uses extremely high powered magnets to produce an image, any piercings, metal implants, and even some tattoos can pose a threat to safety. Make sure to tell your doctor about any such items.

Rarely, a serious reaction may occur from the dye used in some MRI imaging procedures. The dye is composed of gadlinium, an element that helps image certain structures in the body. This is not required in all procedures, but may be indicated in some. Because of this rare problem, it is standard procedure to check kidney functions before administering the contrast dye.

Who uses MRI?

Many doctors are beginning to use MRI more often. In podiatry, MRI can be used to image things like ligament tears, ankle sprains, stress fractures, and other painful problems that may be difficult to spot with an x-ray. The MRI enhances detail, which makes it easier to pinpoint the problem.

For foot and ankle problems, there are special devices that can be placed around only the foot and ankle, avoiding the necessity to place the whole body in the MRI machine. This is beneficial to the patient, as it can sometimes be an anxious situation lying in an MRI tube for an extended period of time.

What else should I know?

Because of the nature of the equipment, it can sometimes be a nervous experience lying down in an MRI tube. For some, your doctor may give a sedative to help you relax long enough to take the image. It is important to remain still in the MRI tube, so as not to distort the image. In general, children have a difficult time lying still in the machine and for more info please click here

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Wei Mai

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Wei Mai
Joined: August 22nd, 2019
Articles Posted: 19

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