Kidney, Ureter, and Bladder X-ray


A kidney, ureter, and bladder (KUB) x-ray may be performed to assess the abdominal area for causes of abdominal pain, or to assess the organs and structures of the urinary and/or gastrointestinal (GI) system. A KUB x-ray may be the first diagnostic procedure used to assess the urinary system.

X-rays use invisible electromagnetic energy beams to produce images of internal tissue, bones, and organs on film. X-rays are made by using external radiation to produce images of the body, its organs, and other internal structures for diagnostic purposes. X-rays pass through body tissue onto specially treated plates (similar to camera film) and a "negative" type of picture is made (the more solid a structure is, the whiter it appears on the film).

Reasons for the Procedure

A KUB x-ray may be performed to diagnose the cause of abdominal pain, such as masses, perforations, or obstructions. A KUB x-ray may be taken to evaluate the urinary tract before other diagnostic procedures are performed. Basic information regarding the size, shape, and position of the kidneys, ureters, and bladder may be obtained with a KUB x-ray. The presence of calcifications (kidney stones) in the kidneys or ureters may be noted.

There may be other reasons for your physician to recommend a KUB x-ray.

Risks of the Procedure

The amount of radiation used during an x-ray procedure is considered minimal. Therefore, the risk for radiation exposure is very low.

Notify your physician if you are pregnant or suspect that you may be pregnant. Radiation exposure during pregnancy may lead to birth defects.

There may be other risks depending upon your specific medical condition. Be sure to discuss any concerns with your physician before the procedure.

Certain factors or conditions may interfere with the accuracy of a KUB x-ray. These factors include, but are not limited to, the following:

  • Recent barium x-rays of the abdomen
  • Gas, feces, or foreign body in the intestine
  • Uterine or ovarian masses, such as calcified fibromas of the uterus or ovarian lesions

Before the Procedure

  • Your physician will explain the procedure to you and offer you the opportunity to ask any questions that you might have about the procedure.
  • Generally, no prior preparation, such as fasting or sedation, is required.
  • Notify the radiologic technologist if you are pregnant or suspect you may be pregnant.
  • Based upon your medical condition, your physician may request other specific preparation.

During the Procedure

A KUB x-ray may be performed on an outpatient basis or as part of your stay in a hospital. Procedures may vary depending on your condition and your physician's practices.

Generally, a KUB x-ray follows this process:

  1. You will be asked to remove any clothing, jewelry, or other objects that might interfere with the procedure.
  2. If you are asked to remove clothing, you will be given a gown to wear.
  3. You will be positioned in a manner that carefully places the part of the abdomen that is to be x-rayed between the x-ray machine and a cassette containing the x-ray film. You may be asked to stand erect, to lie flat on a table, or to lie on your side on a table, depending on the x-ray view your physician has requested. You may have x-rays taken from more than one position.
  4. Body parts not being imaged may be covered with a lead apron (shield) to prevent exposure to the x-rays.
  5. Once you are positioned, the radiologic technologist will ask you to hold still for a few moments while the x-ray exposure is made.
  6. It is extremely important to remain completely still while the exposure is made because any movement may distort the image and even require another x-ray to be done to obtain a clear image of the body part in question.
  7. The x-ray beam will be focused on the area to be photographed.
  8. The radiologic technologist will step behind a protective window while the image is taken.

While the x-ray procedure itself causes no pain, the manipulation of the body part being examined may cause some discomfort or pain, particularly in the case of a recent injury or invasive procedure, such as surgery. The radiologic technologist will use all possible comfort measures and complete the procedure as quickly as possible to minimize any discomfort or pain.

After the Procedure

Generally, there is no special type of care following a KUB x-ray. However, your physician may give you additional or alternate instructions after the procedure, depending on your particular situation.


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