A CT urogram is a test that uses a CT scan and a special dye or contrast medium. It allows doctors to diagnose problems such as kidney and bladder stones, certain cancers, and structural irregularities.

A doctor may recommend a CT urogram if a person experiences certain urinary tract symptoms, such as pain or blood in the urine.

This article will explore why doctors may recommend a CT urogram, what the procedure involves, and some possible risks. It will also discuss when a person should contact a doctor.

doctor with patient by ct scannerShare on Pinterest
Photo editing by Stephen Kelly; FS Productions/Getty Images

A CT urogram is a test that uses a CT scan and a special contrast medium or dye that a doctor injects into a vein. The contrast dye provides a high quality image to allow doctors to look at the urinary system and make a diagnosis.

A CT scan is a form of medical imaging that allows doctors to see a picture of the inside of the body without the need for surgery.

The CT scanner is a short tunnel that contains a rotating X-ray machine. A person lies in the scanner while the inside portion rotates and takes a series of X-rays from various angles.

A computer then combines these images to allow the doctor to visualize cross-sections or three-dimensional images of a particular area of the body. Unlike traditional X-rays, which show bones, these images also show details of soft tissues and blood vessels.

In general, during a CT urogram:

  • A doctor will first conduct a non-contrast scan. This can show kidney stones and any major structural irregularities.
  • They will then inject the contrast, and a second scan will show the soft tissue of the kidneys, bladder, and adrenal glands in enhanced detail.
  • They will then conduct a third scan just a few minutes later. This will show the contrast draining down into the bladder, which gives information on the kidney collecting systems and bladder.

Doctors use CT urograms to examine the urinary system, including the kidneys, bladder, and ureters. The ureters are the tubes that carry urine from the kidneys to the bladder.

Doctors can use CT images to see if the internal structures appear healthy and work correctly and to check for any signs of disease.

A doctor may recommend a CT urogram if a person is experiencing blood in the urine, known as hematuria, or pain in the groin or lower back.

The results of the CT urogram can help doctors diagnose conditions such as:

The steps of the CT urogram procedure may differ among hospitals or for each individual. Generally, however, people can expect the following:

  1. When the person arrives at the hospital, a doctor will explain the procedure. They may also provide a questionnaire for the person to complete.
  2. The person will then change into a hospital gown. They must remove any jewelry because metal can interfere with the scanner.
  3. The doctor will insert a small tube or cannula into the back of the person’s hand or arm.
  4. The person will then go into the room containing the CT scanning machine.
  5. The doctor may give the person furosemide, which is a drug that increases urine production and can help with the imaging.
  6. The doctor will then inject a contrast dye into the cannula. The contrast dye may cause the person to feel hot and flushed, have a metallic taste in the mouth, or feel as though they need to pass urine.
  7. The person will lie down on the CT machine bed. They will usually lie on their back, but sometimes, they may need to lie on their front.
  8. Once the doctor is sure that the person is in the correct position, they will leave the room. They can talk to the person through an intercom and see them through the control room window.
  9. The bed moves backward and forward through the CT scanner’s central hole as it takes detailed pictures. During the scan, the person will likely hear whirring noises from the scanner.
  10. The doctor may ask the person to hold their breath, move position, or use the bathroom to empty their bladder before carrying on with the scan.
  11. When the scan is complete, the doctor will return and lower the bed so that the person can get up easily.
  12. The procedure will take around 90 minutes. It is usually painless.
  13. After the urogram, the doctor will remove the cannula from the person’s arm.
  14. The person must stay in the hospital for around 15–30 minutes to make sure that they have no reaction to the contrast dye and are feeling well.
  15. The person can then go home and eat and drink normally.

For most people, a CT urogram is a safe procedure, but there are some possible risks. These include:

  • Allergic reaction: Though rare, some people may have an allergic reaction to the contrast material. This reaction may manifest as itching, hives, weakness, sweating, or breathing problems. Medications can help manage any reactions.
  • Bruising and swelling: This may appear around the injection site and can be painful.
  • Kidney problems: The contrast material could negatively impact the kidneys. However, a doctor will check a person’s blood before the procedure to ensure that their kidneys are working well.
  • Radiation: The CT scan involves radiation, which can slightly increase someone’s cancer risk in the future.
  • During pregnancy: If the person is pregnant, the doctor may prefer to use another imaging test. It is important for people to tell the doctor if they are pregnant or think they might be pregnant.

Following the CT urogram, the radiologist will review and interpret the results. They will then forward the report to the person’s doctor.

CT urography is a preferred technique for providing accurate information to diagnose many urinary tract problems, including:

  • kidney and bladder stones
  • masses in the kidneys
  • urinary tract infections (UTIs)
  • trauma
  • obstructions in the urinary tract

This form of imaging can show subtle irregularities in the urinary system. These include papillary necrosis, which is a type of kidney damage, and renal tubular ectasia, which is a developmental condition of part of the kidneys.

However, a CT urogram may not find all types of tumors, including some types of bladder tumors.

If a person has blood in the urine, a doctor may recommend a cystoscopy. This involves inserting a tube with a microscope attached into the urethra and bladder to examine them.

If a person is experiencing any urinary tract symptoms, they should contact a doctor for advice.

Without treatment, urinary tract symptoms can cause severe health issues. Likewise, untreated kidney infections can lead to problems such as kidney disease, high blood pressure, or kidney failure.

UTIs during pregnancy can also be dangerous for both the pregnant person and the fetus.

If kidney stones remain untreated, they can block the urinary tubes, which increases the risk of infection and can put a strain on the kidneys.

If a doctor recommends a CT urogram and the person has any concerns about the procedure, they should discuss the possibility of having a mild sedative. Mild sedation can help alleviate anxiety and any feelings of claustrophobia during the procedure.

A doctor may recommend that a person undergoes a CT urogram because they have been experiencing urinary tract symptoms.

The procedure involves injecting a special dye into a vein in the hand or arm. The person will then lie on a bed inside the CT scanning machine as it takes a series of X-rays. A computer will then form these X-rays into a high quality image. The procedure takes around 90 minutes.

This form of imaging is extremely useful in diagnosing issues with the urinary tract, such as kidney stones, cancer, or obstructions.