A kidney, ureter, and bladder (KUB) study is an X-ray procedure that assesses the organs of the urinary system and gastrointestinal system. Physicians use the procedure to help diagnose urinary disorders. It is also often used to diagnose causes of abdominal pain. Information including the size and position of the bladder, kidneys, and ureter may also be viewed.
During the test, energy beams from an X-ray machine produce images. The procedure allows doctors to view certain structures of the digestive system, including the intestines and stomach. The KUB procedure can diagnose certain gastrointestinal conditions, such as an intestinal blockage, foreign objects in the stomach, and some tumors.
The study can also identify kidney stones and certain types of gallstones.
It can be used after a procedure. For example, after the insertion of a feeding tube or ureteral stent, a KUB study can confirm that the device was placed in the correct location.
Candidates for a KUB study include people who experience abdominal pain but have not identified the cause. People who have symptoms of gallstones or kidney stones may also be candidates for the procedure, which may confirm a diagnosis. Someone who has swallowed a foreign object may also benefit from the procedure, which can determine whether or not the object is in the stomach.
There are few if any side effects of having a KUB study. In some cases, lying in the correct position and holding still for the X-ray may cause minor discomfort.
The procedure is performed in a radiological department or center usually by an X-ray technician. Radiation is emitted from an X-ray machine. The procedure can be done on either an outpatient or an inpatient basis.
What Are the Steps?
Before a KUB study, patients must change into a hospital robe or gown and remove jewelry. The technician will explain the procedure, which will likely include the following steps:
- The technician will position the patient depending on which view the physician would like to obtain. The patient may have to lie on their side, face up, or stand.
- A lead apron is sometimes placed over parts of the body that are not undergoing the X-ray. This is done to protect them from radiation emitted from the X-ray machine.
- Once the patient is positioned correctly, the X-ray machine is directed at the body. The patient must remain still as the images are taken.
In some cases, multiple views are needed. This requires that the patient move into another position as directed so that the technician can obtain multiple angles.
During a KUB study, the patient is exposed to low levels of radiation. The risks of radiation exposure from an X-ray are considered minimal, compared with the benefits of the test (University of Maryland Medical Center).
Preparation for a KUB study is usually minimal. Since radiation is used during an X-ray, a patient who is or may be be pregnant should notify her doctor, who will determine whether special precautions should be taken. In some instances, the doctor may recommend not performing the procedure.
Additionally, the doctor may also recommend that patients avoid taking medications that contain bismuth it for a few days before the test. Bismuth, which is used to treat diarrhea and heartburn, can interfere with abdominal X-ray results.
X-ray results are usually available within a few minutes. A radiologist will often have to view the X-ray films in order to interpret the results. Results of a KUB study may show injuries to the stomach or intestines, fluid in the abdominal cavity, or a blockage of the intestines. In addition, results may show the presence of kidney stones or gallstones.
After the procedure, depending on the results, additional testing may be needed.