How is megaureter diagnosed?
If your child has megaureter, doctors must look for what's causing it and that is what will determine the course of treatment. So if your child has been referred to a specialist and megaureter is suspected, there will be a complete evaluation of the entire urinary tract. Megaureter may be detected during an initial evaluation that includes an ultrasound of the kidneys, ureters and bladder. Other studies are usually needed to confirm the diagnosis and to determine the cause. These may include:
- intravenous pyelogram (IVP), which allows doctors to see the anatomy of the ureter and assess how well your child's kidneys collect and drain urine. This test also allows doctors to estimate the diameter (width) of the ureter. In general, megaureter is a ureter with a diameter of more than seven to ten millimeters.
- voiding cystourethrogram (VCUG) This specialized x-ray is used if the doctor suspects that vesicoureteral reflux (backward flow of urine from the bladder to the ureter and/or kidney) is causing the problem.
- A renal (kidney) scan is used if the doctor suspects an obstruction at the ureterovesical junction (where the ureter meets the bladder). This scan provides very detailed information about kidney function. Along with the IVP, it is particularly helpful in identifying and assessing the degree of blockage in this kind of obstruction.
Once the doctor has checked for vesicoureteral reflux and obstruction, he or she will assign your child's megaureter or dilated upper urinary tract into one of the four following categories:
- refluxing megaureter: Vesicoureteral reflux alone is responsible for the megaureter.
- obstructed megaureter: Significant blockage the ureterovesical junction (UVJJ) alone is responsible.
- refluxing and obstructed megaureter: Both vesicoureteral reflux and blockage at the UVJ are present.
- nonrefluxing and nonobstructed megaureter: The upper urinary tract is dilated (wider than normal) but no evidence of reflux or clinically significant obstruction can be determined.
Even after the cause of your child's megaureter is determined, the doctor may want to perform additional tests to get a more complete picture of kidney and bladder function. These tests may include:
- specialized renal scans and/or laboratory (blood and urine) tests
- baseline serum creatinine level - this estimates kidney function and is essential for follow-up care, especially if your child has bilateral megauters (both ureters are affected).
- urodynamic evaluation - these tests measure how well the bladder stores and empties urine.