With the exception of dermatology, most doctors are treating conditions that they cannot see with the naked eye. In order to overcome this hurdle, many different types of imaging techniques and instruments have been developed in order to allow the doctor direct visualization of the problem area. Let’s discuss the imaging most often used in podiatry.
The most commonly used imaging technique in podiatry is radiographs, or x-rays. Although there are many exceptions to this rule, most people who walk into a podiatrist’s office will get x-rays. X-rays are the best to order when a patient’s main complaint could potentially involve the bones or joints. X-rays give only two dimensional images, so it is necessary to take x-rays from multiple angles so that the doctor can mentally put the images together to form a three dimensional picture. X-rays give the doctor important clues in figuring out the pain a person is experiencing. Fractures, foot mal-alignment, and arthritis can be diagnosed with simple x-rays. If a person has stepped on a foreign object, x-rays can help to locate the position of it. X-rays also can help to push the doctor to order additional tests or refer out to a different specialist if certain signs are present suggesting disease like rheumatoid arthritis, peripheral arterial disease, or other systemic disease. It may even be necessary to get an x-ray with a severely infected ingrown toenail to see if the infection has gotten into the bone.
A concern that some patients have is the radiation associated with x-rays. This was a problem in past decades with more primitive x-ray machines. However, modern x-ray machines minimize the scatter of x-rays by directing the beams directly at the target object and having a very short exposure time. Lead is worn to protect against the small amount of scatter. X-rays are avoided if the patient is currently pregnant. You can be assured the amount of radiation received by the foot is very small. In fact, an x-ray exposes you to the same amount of radiation you would receive by spending about 5 minutes in the sun. When compared to tanning, sun-bathing, or going without sunscreen in the sun, the radiation of an x-ray is insignificant.
Even though x-rays show bones and joints very nicely, they do not show much in terms of muscles, tendons, ligaments, or blood flow. In some complicated fractures, it may be hard to determine the extent of the fracture with only an x-ray. In these cases, ultrasound, Magnetic Resonance Imaging (MRI), computed tomography (CT or CAT Scan), or bone scans may be used. We will discuss each of these imaging techniques in the upcoming weeks.