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.
In our next post, we’ll discuss bone scans, another type of imaging that can be useful in diabetic conditions and infections.