What is Computerized Tomography (CT) or CAT Scan?

CT (Computerized Tomography) or CAT (Computerized Axial Tomography) is a highly advanced computerized x-ray machine used to obtain images—or slices—of the body in the axial plane, much like slices of bread. The CT scanner obtains image data from different angles of the body, and then uses computer processing of the information to show a cross-section of body tissues and organs with great clarity. Below is an example of a CT image of the abdomen:

In August 2005 we installed our own CT scanner to assist in the determination of urologic conditions for our patients. CT imaging gives our urologists the ability to provide treatment plans for kidney stones, hematuria (blood in the urine), kidney masses, and other diagnoses. For the most part, our urologists will order studies revolving around the pelvis and abdomen.

How does the procedure work?

Inside the CT scanner is a doughnut shaped rotating gantry that has an x-ray tube mounted on one side, and an arc-shaped detector mounted on the opposite side. An x-ray beam is emitted in a fan shape as the rotating frame spins the x-ray tube and detector around the patient. Each time the x-ray tube and detector make a 360-degree rotation and the x-ray passes through the patient’s body, the images are reconstructed by a dedicated computer into a two-dimensional image of the section that was scanned.

How is the CT scan performed?

The technologist begins by positioning the patient on the CT table. As the study proceeds, the table will move slowly into the CT scanner. Depending on the area of the body being examined, the increments of movement may be so small that they are almost undetectable, or large enough that the patient feels the sensation of motion.

Your physician may have ordered your study to be done with contrast in order to enhance the visibility of certain tissues or blood vessels.

How Should I Prepare for the Procedure?

You should wear comfortable, loose fitting clothing for your CT exam. Metal objects can affect the image quality, so please avoid clothing with zippers and snaps. You may also be asked to remove hairpins, jewelry, eyeglasses, hearing aids, and removable dental work.

Is CT Imaging Safe?

Yes, CT imaging is considered a safe examination. In general, the diagnostic benefit of a CT scan outweighs the risk of x-ray radiation exposure or injection of imaging contrast (if applicable). If your procedure involves contrast, we pre-screen all patients for prior contrast reactions, history of renal insufficiency, and diabetes to avoid any contrast reactions. Pregnant women should not have a CT exam or any x-ray examination, especially if the woman is in her first trimester (first of three 3-month periods of pregnancy).

Please inform your physician’s staff or the CT technologist if there is any chance you may be pregnant.

Patient CT Results

All of our CT studies are read in a digital manner by the radiologists at Sierra Imaging This type of joint venture makes it possible for a radiologist to read the CT study within 30 minutes, and in emergent cases we get results within the hour. The radiologist is responsible for everything that is scanned, so often incidental findings come up that are not related to urology but we will refer to the proper doctor to resolve your problem. The result service we receive makes it possible for us to treat our patients in a very fast and efficient manner. We have a dedicated CT scheduler who sets up your appointment and also requests any prior CT of the abdomen and pelvis you may have had in the past. These prior studies are requested and used by the radiologist to track time progression of a given condition you may have, and is very important in the reading of your study. Unless we are waiting on prior studies to be delivered for comparison results are usually ready on the same day of examination.

Depending on your urologist’s protocol, you may be brought back to the office for a follow-up appointment, or you may receive a phone call with your results.

CT Billing

Sierra Imaging Associates located here in Fresno is a radiology center that reads all of our CT and ultrasound studies done in our office. Sierra Imaging bills for the professional component (CT reading)of the study, and they will bill your insurance. Please be advised you may receive a bill from Sierra Imaging. Urology Associates of Central California (UACC) will be billing your insurance for the technical component of the study, which is the actual scan. You may receive a bill from us as well if you have an out-of-pocket expense from your insurance.

CT Preparation

Studies Without Contrast

Please do not eat or drink anything 4 hours prior to the exam.

Studies With Contrast

You should have received one bottle of oral contrast from our office. Please shake the bottle of contrast before drinking. You may refrigerate the contrast to make it taste a little better. Do not eat or drink anything at least 4 hours prior to your appointment.

  1. You may take all non-diabetic medications as you normally do with water, even if it is during the four-hour time frame.
  2. Diabetic patients taking Glucophage type medications (i.e., Glucovance, Advandamet, Metformin HCL) must discontinue their use 2 days before the CT study. You must not take this medication for a period of 2-5 days after the study. These medications can reduce the body’s ability to flush the IV contrast from your kidneys.
  3. Drink the first bottle of oral contrast 1 hour prior to your appointment.
  4. You will be given a second bottle of oral contrast to drink 15 minutes prior to your CT study in our office.
  5. You will be asked to drink about 16 oz. of water immediately before the exam.
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