Urologic Radiology

In medicine, "imaging" is the term used for any method to take pictures of bones and organs inside the body. One of the most basic imaging methods is with X-ray radiation. X-rays can help your health care team find the cause of a health problem. For example, X-rays may be used to find a tumor, kidney stones or a developmental problem.

An X-ray (or conventional radiology) is a form of radiation made by special machines that take pictures of the inside of your body. Structures that are dense, like bones, look white on the film. Structures that contain air, like your lungs, look black. Muscle, fat and fluid will show as different shades of gray.

For more details visit our web article on X-rays.

Angiography, also called Arteriography, is the X-ray imaging of blood vessels using a contrast agent (dye), which is given through an IV. The dye makes the blood vessels visible with an X-ray.

Its purpose is to show the blood supply moving to an organ. For example, an angiogram can show how blood flows to the kidney from the aorta and renal arteries. Angiography can be useful for both diagnosis and treatment of disease.

Angiography is helpful to:

Antegrade pyelography uses a special contrast agent (dye) to see detailed X-ray images of the inside of the upper urinary tract (kidney and ureter). The dye is given through a tube that is already in the kidney, or through a needle that is passed through the skin into the kidney directly. The needle is placed in the part of the kidney that collects urine. The doctor pushes the dye and X-rays show how well the kidney drains. The dye then passes into the ureter, the tube that drains the kidney, and empties into the bladder.

It is used to diagnose hydronephrosis, ureteropelvic junction (UPJ) obstruction and some types of tumors and obstruction of the ureters (like from a kidney stone).

For more details, please visit our web article on Antegrade Pyelography.

Bone scans may be used to see if prostate, bladder, kidney , testicular or penile cancer has spread to the bones. Although the number of bone scans has gone down over the years, these studies are helpful in finding out if if cancer has travelled outside the main organ.

In these studies, a radionuclide is injected into the body through an IV. Over a period of hours, images are taken of the bones in the body. Absorption of the radionuclide in a specific area, appearing as bright increased activity on the images, may suggest trauma or cancer in the bone.

Computed Tomography (CT) is used by doctors to see and evaluate many layers of tissue and organs. It is one of the best tools to diagnose problems in the urinary tract and renal systems.

The CT scan uses special X-ray equipment that rotates around the patient to gather data from many angles: top to bottom (axial), front to back (coronal) and side to side (sagittal). The beams pass through the tissue as detectors measure thousands of X-ray images. A computer then makes detailed pictures (slices) that are shown on a screen and presented like a cut loaf of bread, one slice after another.

Cystography uses X-rays and contrast (dye) to look at the inside of the bladder for a blockage or birth defect. It can find a vesical fistula, a bladder rupture or vesicoureteral reflux (VUR).

There are two versions of this test. The first type is one with X-ray. The second type is with nuclear medicine. Many doctors believe the radionuclide cystography with nuclear medicine is better for tracing urine flow through the urinary tract. It also uses less radiation and does not rely on fluoroscopy.

To instill the dye, the doctor will first insert a catheter through the urethra to the bladder and then inject the dye through the catheter. X-ray pictures are taken from different angles as the bladder fills. At the end, the bladder is drained and more images are taken after the bladder is empty.

Called a VCUG or cystogram, this test shows your doctor the size of your bladder and how well it can drain. The test is also used to pinpoint anything abnormal about the urethra and the bladder. For example, it can find a problem with the narrowing of the urethra (stricture), or help find VUR (vesicoureteral reflux), a condition in which urine flows back up from the bladder through the ureter and into the kidney.

For more details, please visit our web articles on Contrast and Radionuclide Cystography, Radionuclide Cystogram, and Voiding Cystourethrogram.

Intravenous pyelography (IVP) is an X-ray exam that uses contrast (dye) to highlight the inside of the kidneys, ureters and bladder. It provides details about renal function to see how well your system handles fluid waste. This helps your health care team find problems in the urinary system. While there are rare times this test is still performed, most cases that require this type of test are done with CT scan and a drainage phase, called a CT Urogram.

The dye is given through an IV. The amount of dye given is based on the patient's kidney function and body weight. Children get less, and larger people get more. As the kidney filters the blood that flows through it, the dye passes into the urine. X-rays are taken in time intervals that allow the radiologist to follow the passage of the dyed urine into the kidney, down the ureter and into the bladder.

The exam is used to diagnose why a patient has blood in their urine or pain in their side or lower back. It can also be helpful for seeing how well the kidney and ureter function. It can find:

• Kidney stones
• Enlarged prostate
• Tumors in the kidney, ureters or bladder
• Scarring from urinary tract infection
• Birth defects of the urinary tract
• Poor function of the ureter

Magnetic resonance imaging (MRI) uses radio waves and a strong magnetic field to create highly complex and accurate pictures. It can show soft tissues so specifically that it can detail blood vessels and other small structures.

Since the MRI can create three-dimensional images, it is often used to help diagnose and treat cancers. Contrast agents given through an IV can help outline the inside of the urinary tract, similar to what a CT can do. The agents used for MRI are less risky for the kidney as compared to CT, so for patients with kidney issues and some kidney failure, MRI may be preferred.

Nuclear medicine imaging (NMN) or radionuclide imaging is a valuable tool for diagnosis. It is used to help find cancers, heart disease, gastrointestinal, endocrine, neurological disorders and other problems. Because tools using nuclear medicine can pinpoint molecular activity in the body, it can find disease early, when it is most easily treated.

This test shows both the anatomy of an organ or body part and how it functions. Information about organ function means this exam helps find problems much sooner than other imaging exams.

For this test, urologists inject a radioisotope "tracer" through an IV, which travels in the blood to the kidney system. The tracer is a molecule that has a radioactive atom or "tag" attached. The tags most often used are iodine-123 or 131, or technetium. They can be followed through the kidney as it filters blood and marks with special nuclear detectors. A series of X-ray images of the kidneys are then collected to see blood flow and function.

Radionuclide imaging is safe, gives off less radiation than an X-ray and carries no allergic risks.

Retrograde pyelography uses a contrast (dye) to get detailed X-ray pictures of the inside of the upper urinary tract. For this, dye is injected into the ureter creating pictures of the ureter and the kidney collecting system. This test is used when other imaging exams do not give a clear enough view, or other tests (such as a CT scan) cannot be done for some reason (such as, altered function of the kidney). This test helps your health care team diagnose blockages in the urinary system. It also is used with cystoscopy and during surgery to map the anatomy fo the upper urinary tract and to look for hematuria (blood in urine), cancer and kidney stones.

Retrograde pyelography is performed at the time of a cystoscopy, either in the office or in the operating room with anesthesia. Then a catheter is placed through the scope and into the patient's bladder, then into the opening of the ureter. The dye is injected by the surgeon into the end of the catheter. A special device, called a C-arm, is used to take X-rays of the urinary tract (fluoroscopy) in real time. These images can both diagnose a problem and guide surgery.

Retrograde urethrogram is a tool used to evaluate trauma to the penile urethra or urethral disease, such as strictures.

For this test, a catheter is inserted about two centimeters into the penis. Contrast (dye) is injected through the catheter. Several X-rays are taken with a C-arm using fluoroscopy, to clearly see the inside of the urethra. If needed, the catheter is moved to fill the bladder. The patient is instructed to pass urine while many more X-rays are taken, which shows how the bladder empties and the urethra looks.

For more details, please visit our web article on retrograde urethrogram.

Ultrasound uses high-frequency sound waves to create real-time images. It is a simple and painless way for urologists to look at many organs. It is flexible and offers helpful information, without using dyes or radiation.

A small probe (transducer) and gel are placed on the skin. The transducer collects the sound waves from organs. The computer in the machine sets a gray scale based on the speed on which the sound waves are returned and creates an image. The images look like thin, flat sections of the body on a computer screen. Newer technology can create three-dimensional (3-D) ultrasound images.

Venography is an X-ray exam that uses an injection of dye to show how blood flows through your veins. Your doctor may use it to find a blood clot, or to prepare for dialysis.

For this test, contrast (dye) is injected into the renal veins through an IV. Then X-ray images are taken within seconds. Giving a medicine called epinephrine, first, may allow for better images. Venography is being done less often, as tools such as Doppler ultrasound have improved.

• Why do you think this test will help me?
• How long will I have to wait until I learn the test results?
• How accurate are the test results?
• What other tests will I need for diagnosis or treatment?
• If a problem is found, what are my next-steps?
• What are the possible side effects of the contrast?
• How can possible side effects be prevented?

Updated November 2024.