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.
