Foot News

When is it necessary to get an MRI?
August 10, 2011

The foot is an extremely intricate and complicated device.  The problems that affect it can be difficult to diagnose and understand.  Radiographic studies such as x-rays, MRI, CAT or CT scan, and bone scans are important ways of visualizing the structures within the foot and ankle.  However, they are expensive and are not a substitute for a careful examination from your doctor.  Radiographic examinations are definitely overused in modern medicine.  So, when are they appropriate?  To answer this, we must look at the problem being examined and the chances that the radiographic study will help answer the questions that help solve that problem.
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MRIs give often critical information about bone and soft tissue structures within the foot.
            When doctors are examining their patients, they should use first the information that is literally at their fingertips.  The examination begins with careful questions of when, where and how.  A complete understanding of the symptoms and how they behave in everyday life will form an accurate picture of the problem.  A meticulous examination of the extremity and the structures around it is then necessary.  This information is then used along with your doctor’s (hopefully) in-depth understanding of the extremity to develop a list of possible causes.  You can simply break these potential causes into categories depending on their severity.  The categories are problems that are life and limb threatening, those that will not get better without specific interventions and those that are uncomfortable and inconvenient, but usually get better on their own. 
            Let’s begin with the last group, the problems that get better on their own.  These do not require expensive radiographic studies.  Pretty simple.  Getting a study to simply visualize a problem on a film is not a cost effective or useful way of evaluating it.
            The second group are those problems that will not get better without specific interventions.  Sometimes, all of the information that is necessary to treat these problems is available through standard studies such as x-ray.  For example, if an ankle fracture is present often it can be seen on x-ray and the diagnosis is pretty plain and the treatment clear. Plantar fasciitis, a common cause of heel pain, can usually be diagnosed by physical examination.
On the other hand, there are problems that are difficult to identify without radiographic studies.  The vast majority of these should not be worked up unless aggressive and complete non-operative treatment has been done and failed.  It is impossible to say whether an unstable ankle or bruised bone will improve with non-operative treatment until it has been tried.  Most of these problems do get better with these non-operative treatments.    These sophisticated studies are sometimes necessary in this group of problems.  The times that the studies are necessary is when (1) the diagnosis is in doubt or (2) a roadmap of the problem is necessary to plan for surgical treatment.
The last group are problems that are life or limb threatening.  Again, many of these problems do not require further testing because the questions that need to be answered prior to treatment have already been answered by less sophisticated tests and simple examination.  When a life or limb threatening problem is suspected, aggressive evaluation including any necessary tests should be ordered and evaluated as soon as possible. 
As mentioned before, these tests are expensive.  Many times the expense is not always completely covered by insurance.  It is your right and your doctor’s responsibility to help you to understand why these tests are being ordered and how the results of the tests will benefit you.  Your doctor should be able to explain why they are absolutely necessary, and if there are less expensive alternatives.  If they are being ordered to identify a problem that may lead to surgery and you are not interested in surgery, this should be cleared up prior to ordering the test.  Sometimes there is not a less expensive alternative, but many times there is.
-Brett Fink, MD, Indiana Orthopedic Center, Indianapolis, IN, (317) 588-2663, co-author of The Whole Foot Book, A Complete Program for Taking Care of Your Feet.
Posted in Foot Disorders, Medical Tips and Pearls, Uncategorized
Tags: Bone scan, CT scan, feet, foot, foot pain, MRI, radiography