To CT or Not CT?

The Benefits of CT over X-rays If you or your pet has ever been to the hospital, chances are that at some point you (or they) have had an x-rays. If you haven’t, I’m sure that you’ve at least seen them on a cartoon, ER, or Grey’s Anatomy.


X-rays are by far the most common imaging modality in medical use today and they are used every day in both human and veterinary hospitals world wide. They are a valuable diagnostic tool for doctors and that can not be denied.

But here is something that you may not have known about x-rays: X-rays are limited in their ability to detect problems.

Now don’t get me wrong, X-Rays are an excellent imaging tool used to diagnose everything from foreign bodies to cancers, and doctors depend on them heavily to diagnose and treat patients daily.

With that being said, regardless of all the benefits that they do provide, they do have and Achilles’ heel.

The simple fact is they are limited in their imaging ability.

In fact the truth is, X-Rays can not image a nodule that is smaller than 5mm (.05 cm).

Now this may not sound too alarming at first glance, but think about it this way:

Essentially an X-Ray can literally be read as clear or normal, while there can still be a ”potential” underlying problem. 

In layman’s terms this means that you or your pet could potential have an x-ray, say a chest x-ray, and the results could come back as normal, BUT there could technically still be a nodule there.

Now of course, we are not trying to scare you or be a doomsday prophet or anything like that. And to be honest, most every doctor out there does a great job and x-rays are quite adequate for diagnosing and treating most things.

But due to the limitations of x-rays, a CT can be and may be recommended as an alternative to an x-ray and often times may be preformed in lieu of, in addition to, or in conjunction with an x-ray due to its superior and more advanced imaging capabilities.

Now you may be asking yourself, “So why not just CT everything.”

Excellent question, but as with everything in life, CTs are not perfect either and there are a few drawbacks, primarily two main issues.

First, the cost.

A CT machine is not only a much more expensive piece of equipment to the hospital versus an x-ray machine, but the maintenance, up keep, and staffing cost more as well.

By the same token and for these reasons, the cost of a CT exam is substantially more expensive.

Secondly, a CT scan produces more radiation than an X-ray machine. Both machines use radiation to produce images (both in safe doses and following guidelines), but a CT produces much more radiation.

If you equate the radiation exposure of an x-ray to being out in the sun for a day, having a CT is comparable to being out in the sun for five days. Again, both are in safe dose and follow strict guidelines, but there is a greater increased risked from repeated CT versus x-rays.

In the end, both x-rays and CTs are excellent diagnostic tools to use in the treatment of your pet and your veterinarian would inform you of the best options available to your particular situation, we just wanted to help create a clear picture when it comes to imaging.

Stay tuned for Pt. 2 of our CT blog series!

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