Detecting Abnormalities
Although UTIs can be treated with antibiotics, it's important for a doctor to rule out any underlying abnormalities in the urinary system when these infections occur repeatedly. Kids with recurrent infections should see a pediatric urologist to determine what is causing the infections.
Some abnormalities can be detected even before birth. Hydronephrosis, when it occurs as a congenital condition, can be detected in a fetus by ultrasound as early as 16 weeks of gestation. In rare cases, doctors may consider neonatal surgery (performing surgery on an unborn baby) if hydronephrosis affects both kidneys and poses a risk to the developing fetus. Most of the time, though, doctors wait until after birth to treat the condition, because almost half of all cases that are diagnosed prenatally disappear by the time a baby is born.
Once a baby suspected to have hydronephrosis or another urinary system abnormality is born, the baby's blood pressure will be monitored carefully, because some kidney abnormalities can cause high blood pressure. An ultrasound may be used again to get a closer look at the bladder and kidneys. If the condition appears to be affecting both kidneys, doctors will usually order blood tests to measure kidney function.
Diagnosis
If an abnormality of the urinary tract is suspected, doctors might order tests to make an accurate diagnosis, including:
Ultrasound
Using high-frequency sound waves to "echo," or bounce, off the body and create a picture of it, an ultrasound can detect some abnormalities in the kidneys, ureters, and bladder. It can also measure the size and shape of the kidneys.
When an ultrasound points to VUR or hydronephrosis, a renal scan or voiding cystourethrogram (VCUG) might give doctors a better idea of what's going on.
Renal scan (nuclear scan)
Radioactive material is injected into a vein and followed through the urinary tract. The material can show the shape of the kidneys, how well they function, if there is damaged kidney tissue, and the course of the urine. A small amount of radiation is received during the test and leaves the body in the urine.
Voiding cystourethrogram (VCUG or cystogram)
A catheter (a hollow, soft tube) is used to inject an opaque dye into the bladder. This X-ray test can diagnose VUR and identify problems with the bladder or urethra.
Cystoscopy
A cystoscope uses lenses and a light source within a tube inserted through the urethra to directly view the inside of the bladder. It's used when other tests or symptoms indicate a possible bladder abnormality.
Intravenous pyelogram
Opaque dye is injected into a vein, and then X-rays are taken to follow the course of the dye through the urinary system. Although this test is still used sometimes, the renal MRI and renal scan have replaced intravenous pyelogram in most cases.
Magnetic resonance urography (MR-U)
This procedure, which makes a magnetic resonance imaging (MRI) scan of the urinary tract without the use of dyes or radioactive materials, has been shown to be as accurate as other scans and is now typically done in place of an intravenous pyelogram.