DEAR MAYO CLINIC: I suffered an injury while working out and my primary care physician ordered an X-ray. However, after reviewing the results, my doctor recommended that I have an MRI. I am a very anxious person. Can you explain more about what this type of testing entails and what I can expect?

ANSWER: Understandably, any health care concern can lead to feelings of anxiety and nervousness. Depending upon the situation, your care team may begin with an imaging scan such as X-ray, which is a painless test that gathers images of the structures within the body. If additional information is needed — particularly of the organs or soft tissues in the body — an MRI may be ordered.

MRI, or magnetic resonance imaging, is a medical imaging technique that uses a magnetic field and radio waves to create a detailed image of the organs and tissues in the body.

People often come into an MRI with a lot of misconceptions and just as many questions. Below are the top five questions I answer almost daily. Hopefully this will help bring you a sense of what to expect when undergoing this radiology test.

1. How long will this take?

MRI exams take longer than X-ray and CT scans. The routine appointment time at Mayo Clinic is 45 minutes, though some exams could take as long as four hours to complete.

There are many reasons for this extreme time difference. First, electromagnetism is used to create these images. We can only go as fast as the human body will magnetize. Second, the intention is to create the best imaging possible, which inherently means more time inside the scanner. But the clarity means the radiologists often are able to detect pathology more clearly in our images as opposed to those that come from other facilities.

2. Why do I have to change my clothes and remove my jewelry?

MRI machines have superconducting magnets that generate heat and create an extremely strong magnetic field, so it is imperative to be safe. The magnets can pull ferrous objects, or those containing iron, into the machine with a large amount of force. This also can cause the machine to rotate and twist with the magnets’ flux lines. Nonferrous objects like aluminum or copper will generate heat once inside the scanner, which may cause burns. There have been instances where clothing has been set on fire. To prevent any of these issues, we ask all patients to change into hospital-approved clothing and remove all jewelry and any devices such as cellphones, hearing aids and other items from the body.

3. My doctor said my implanted device is safe. Why do you need my information?

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