We’ve discussed some of the more well-known imaging
techniques used by foot doctors to help understand and diagnose foot pain. There are additional tests that podiatrists
use less routinely, but nonetheless give important information in the right
circumstances. Let’s discuss CT scans
and their use in podiatry.
If you remember when we discussed MRI, we talked about how a
magnet is used to take sequential slices through the foot, which are then
grouped together to give a three dimensional image of foot. CT scans are similar in that they take slices
of the foot like an MRI. However,
instead of using a magnet, CT scans use a computer that generates x-rays. Whereas regular x-rays only give a two
dimensional image, when grouped together, CT scan can give a 3D image.
CT offers some very useful advantages over other imaging
techniques. CT scans allow incredible
visualization of bone. In cases of high
impact injury like falling from tall heights, or dropping a heavy object on the
foot, bone can fracture into many small fragments. In many of these cases, surgery is required
to fix the fractures. CT scans can help
the surgeon to know before surgery how many fragments there are and where they
are located. This allows the surgeon to
plan in advance how to best go about repairing the fractures, and to make the
most appropriate decisions for the patient.
CT scans do have some limitations. The main disadvantage to these scans is the
amount of radiation the patient is exposed to.
When compared to a single x-ray, a CT scan exposes you to several times
over the amount of radiation. For this
reason, in podiatry, they tend to be ordered with very badly fractured heel or
ankle bones. Although CT scans can
differentiate between bone, tendon, and muscle, MRI gives a much clearer
picture of these structures without exposure to radiation.
