CT Scans Explained


Say, for instance, you hurt your leg and need a diagnosis. Most of the time, your routine doctor’s visit goes smoothly and you leave knowing what is wrong and the steps you can take to fix it. However, it is not uncommon to go to the Doctor’s for an appointment and not figure out what is causing your symptoms. In this case, the doctor may request a diagnostic imaging exam. These exams are ordered for many different injuries and ailments. In the case of your leg, you may ask yourself why your doctor ordered a CT scan. Here is everything you need to know about CT scans.

What is a CT scan?

CT (Computed Tomography)-sometimes called a CAT scan, is a noninvasive, painless medical test that helps physicians diagnose and treat medical conditions. Using special x-ray equipment, doctors can determine a diagnosis for certain types of injuries. By sending x-ray beams through a patient’s body to an x-ray detector on the other side, CT scanners help provide an internal image of the area. Then the body goes through the arc-like structure, the scanner produces several internal images. These images are created by comparing the strength of x-ray beams measured at 1000 times per second. A computer joins these areas together in a cross-sectional view of the area after the images are compiled. But why not just order an x-ray? CT scans of internal organs, bone, soft tissue and blood vessels provide greater clarity than conventional x-ray exams.

How long do CT scans last?

Many patients worry about the duration of their exam and how comfortable they will be. They often hear about lengthy MRI sessions and think that every diagnostic imaging exam will be like that. CT scans, fortunately, are considerably quicker than MRIs. The scan generally takes around 15 minutes to complete. You will be asked to hold still and hold your breath during portions of the exam. The technologist will position you on the examination table, usually lying flat on your back or possibly on your stomach. You will be alone in the exam room during the CT scan, however, the technologist will be able to see, hear and speak with you at all times via a 2-way intercom system. In addition to the quickness of the scan, CT scans also do not come with overwhelming noises, limited space, and the pressure to lay as still as possible.

Do CT scans result in radiation exposure for the patients?

Another common concern is whether CT scans emit radiation. They do emit radiation with a dose anywhere between 2 and 10 mSv. Radiation exposure in this range is similar to the amount of background radiation an average person is exposed to after 5 years. While this exposure is minimal, certain individuals, like pregnant women, should be advised to avoid any CT scans during pregnancy. If you have any questions or concerns about CT radiation, ask your doctor to see if you are at risk.

Are there any possible limitations to CT scans?

There are not a lot of significant problems or limitations when it comes to whether or not you can get a CT scan. However, always ask your doctor if you have questions or concerns. Occasionasionally CT scans struggle to capture multiple, layered images for more comprehensive imaging. In that case, patients will need to have their symptoms examined from multiple angles. The patient will likely need to reposition themselves to successfully capture the whole picture, which may prove inconvenient for some. On the other side, CT scans are advantageous because they can accommodate patients with metal implants, tattoos, cardiac pacemakers, and implants. Some diagnostic exams, like MRIs, cannot easily accommodate these things.


Seton Imaging is one of the areas longest-established Radiology practices. We are proud to offer our patients a complete range of diagnostic imaging services and procedures. Our experienced and skilled team of radiologists work closely with your referring physician to bring you the best in diagnostic imaging services and the absolute highest quality of care.