Urinary Obstructions

Diagnosis of Urinary Obstruction

The physician may order the following tests, which could reveal a urinary obstruction:

• Urinalysis
• Blood and urine tests to assess kidney function
• Abdominal X-rays

These tests check for urinary tract infection, which can result from an obstruction:

• Urine culture
• CBC test to identify increased white blood cell count

Other tests that can identify a urinary obstruction:

Urodynamic Testing

• Uroflowmeter — Tests the amount of urine and how quickly it comes out. Slowdown of urine flow can indicate an obstruction.
• Postvoid residual — Uses a catheter or ultrasound to measure the amount of urine left in the bladder after urination. More than 1 or 2 ounces may indicate an obstruction.

Cystoscopy
A small, flexible tube which includes an optical system is inserted into the body through the urethra. The optical system allows physicians to see inside the body.

Renal ultrasound
Sound waves are used to produce an internal view of the kidneys, ureters, bladder and urethra.

Voiding cystourethrogram
A catheter, or tube, is inserted through the urethra to fill the bladder with a liquid contrast material. Then the bladder and urethra are X-rayed before and during urination.

Intravenous pyelogram (IVP) or excretory urogram
A contrast material is injected into a vein in the arm. X-rays are taken as the contrast moves through the kidneys, ureters and bladder.

CT scan
This test uses a series of thin X-ray slices to produce two-dimensional images of the urinary system.

CT urogram
This test combines IVP with CT of the abdomen and pelvis.

Renal nuclear scan
Similar to an IVP, except a small amount of radioactive solution is injected and viewed through a special camera. This test can evaluate the kidneys, how they are functioning and if they have been injured by a urinary obstruction.

Abdominal MRI
Powerful magnets and radio waves produce detailed images of the urinary system.