What is CT urography?
This is also called CT IVU, especially in our hospital.
A computerized tomography (CT) urography is an imaging test used to assess your urinary tract. That is the kidneys, the urinary bladder and the tubes (ureters) that carry urine from your kidneys to the bladder, using a CT machine.
During this test or examination, X-rays are used to generate multiple images of the body area in slices and then processed on the computer to generate the final pictures, by a process called image reconstruction.
An X-ray dye (iodine based contrast material) is often injected into a vein in your hand or arm, just before starting this test. The dye flows into your kidneys, ureters and bladder, outlining each of these structures thereby making them clearer to be seen by the doctor.
Why am asked to do CT urography?
This test is often recommended by your doctor if you are having complaints such as pain in your side or back (loin pain) or blood in your urine (hematuria) or if the doctor suspects that you may have any condition that is affecting the urinary tract, such as:
Tumours or cysts
What are the risks associated with CT urography?
With a CT urogram, there is a slight risk of an allergic reaction if the x-ray dye (contrast material) is injected. Reactions are generally mild and easily managed by medication. They include:
A feeling of warmth or flushing
Pain near the injection site
Also having this test multiple times may somewhat increase your chances of certain cancers more than is seen in the general population. However, your doctor must have weighed the risk versus the benefits. Most times, the benefits of an accurate diagnosis often outweigh this risk.
Don’t forget to tell your doctor if you are pregnant or think you could be pregnant. Although the risk to the unborn baby is small, your doctor may consider shifting the test date or recommend the use of another imaging test.
How do I prepare for this test?
Before a CT urogram,
You may be asked to abstain from food for about 4-6hours before coming for this examination.
You will be expected to provide information like whether you:
Have any allergies, particularly to iodine
Are pregnant or think you might be pregnant
Have had a previous severe reaction to X-ray dyes
Are taking any medications, such as metformin (Glucophage), nonsteroidal anti-inflammatory drugs (NSAIDS), anti-rejection drugs or antibiotics
Have had a recent illness
Have a medical condition, including heart disease, asthma, diabetes, kidney disease or a prior organ transplantation
You may be required to drink water a few hours before the study to keep organs well hydrated and to expand (distend) your bladder with urine.
You will also be asked to sign a consent form after the procedure has been thoroughly discussed with you.
What can I expect during and after the test?
Immediately before your CT urogram, a radiographer or any member of the radiology department will:
Ask you questions about your medical history
Check your blood pressure, pulse and body temperature
Ask you to change into a hospital gown and remove jewellery, eyeglasses and any metal objects that may obscure the X-ray images
Put an intravenous access line into a vein in your hand or arm through which the X-ray dye will be injected.
During the examination proper:
You will usually lie on your back on the CT table, though you may be asked to lie on your side or stomach.
Straps and pillows may be used to help you maintain the correct position and keep still during the exam.
The table will move you in and out of the CT x-ray unit, as determined by the attending radiographer.
After the initial in and out movement, the dye will be injected into your body through the IV line. This is usually done automatically in our center using the automatic injector.
You may feel a warm, flushed sensation when the dye is injected, and a metallic taste may appear in your mouth for a minute or two. You may also feel like you have to urinate at that instance. But all these are usually brief.
During the time the machine is taking the images, you will hear a sound from the machine asking you to hold your breath for a second. This is important to keep the images from being blurred.
After a CT urogram
After the CT urogram is complete, the radiologist and /or the radiologist will check to see that the image quality is good for an accurate evaluation.
Then, the IV line is removed from your arm and the IV entry point is covered with a dressing.
You may then return to your normal activities.
A doctor who specializes in reading X-rays (radiologist) will review and interpret the X-ray images from your CT urogram and send a report to your doctor.
Your doctor will discuss the result with you on your subsequent appointments.