Doc: MRI alternatives for those with metal implants

Keith Roach
To Your Health

Dear Dr. Roach: A few years ago, my father had two spinal cord stimulators implanted in his back to help with his lower back pain. He recently had a stroke, and after a CAT scan, was scheduled for an MRI. The MRI was canceled as soon as the technician became aware of his implants.

Are there any alternatives for patients with these implants who are in need of an MRI?


Dear D.T.: An implantable spinal cord stimulator is a device used to send electrical impulses in order to reduce chronic pain, especially in people with unsuccessful back surgery, complex regional pain syndrome and a few other indications. They are used in people who have failed other approaches, and are moderately successful, with some people getting very good relief and others not having much benefit at all. Hence, a trial usually is done to see whether it will be effective in an individual before putting in a permanent device.

Some spinal cord stimulators are made out of metal that is compatible with MRI; however, if it is not, then performing an MRI is dangerous — movement of the unit under the powerful magnetic field is possible, as is a heating up of the metal parts of the unit.

You should find the original informational materials your father should have received when he had the device implanted. If you are unable to locate these, the person who implanted it should have these records.

If you cannot prove that both of his stimulators are approved for MRI, then he is left with a CT scan, sometimes combined with a dye study, a myelogram. We used these a lot before MRI became available, though they don’t have the incredible resolution of a modern MRI machine.

Dear Dr. Roach: I get pressure in the center of my chest, behind the breastbone, after walking at a moderate speed or other moderate exercise, and sometimes with emotional excitement. The pressure is relieved with stopping the exercise. I have noticed that I feel better if I have a snack between meals.

Do you have any suggestions of the possible cause?


Dear P.R.: Although you haven’t told me your age, this history makes me very concerned for coronary artery disease, blockages in the arteries to your heart. Angina pectoris, which is Latin for “chest pain,” is not usually perceived as pain. Most people describe a pressure, tightness or discomfort.

The fact that it comes on with exercise and is relieved by stopping is highly suggestive — I would get to your doctor right away and ask about getting an evaluation. This may include a stress test.

The more risk factors you have, the more likely these symptoms are to represent heart disease. Risk factors including being male, of older age, history of smoking, high blood pressure, unfavorable cholesterol panel, family history of heart attack or blockages, being overweight (especially around the middle), poor diet and lack of exercise.

Getting better with a snack is not a usual feature of heart disease, and it is possible that your symptoms are related to a gastrointestinal problem. However, it’s a physician’s job to consider all the data and to carefully consider the most dangerous possibilities.

If you have several risk factors, most physicians hearing your symptoms would get you evaluated right away, or send you to an expert to do so.

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