Investigations in Pediatric Urology
1. Routine Urine Examination: This is often the first investigation in majority of Pediatric Urological disorders. Freshly voided urine is examined under microscope for any signs of infection (bacteria, pus cells), bleeding (red blood cells), Crystals (stones) or casts (nephritis). Also a chemical analysis is done to see any protein loss, pH (acidic or alkaline), specific gravity (concentrated or thin urine) and any sugar in urine.
2. Urine culture: This involves storing the urine in special containers to look for any growth of bacteria. This investigation is done where we suspect urinary infection. It takes 2-3 days for the report to be ready. It tells us which bacteria are present in the urine and which antibiotic should be used against it to fight infection. As such it avoids wastage of antibiotics and an effective and targeted therapy can be provided.

3. Blood tests

  • Serum Creatinine: Creatinine is a by-product of muscle breakdown which occurs at a small rate daily commensurate with the muscle mass and regeneration. Creatinine is normally excreted by the kidney and so the blood or serum levels remain low. Increased Serum Creatinine signifies loss of kidney function. But it is only a rough indicator of overall kidney function as levels rise only after a substantial amount of functioning kidney tissue is lost. Also, the levels vary with age and height, so these should be taken into account.
  • Blood urea: urea is breakdown product of proteins and is normally excreted in urine. Its values rise with falling renal function. It is less specific when compared to serum Creatinine.
  • Electrolytes: These are chemicals dissolved in blood and body fluids which ensure normal functioning of the body. These are Sodium, Potassium and Calcium. Their values may change in kids with renal disease and so these may also be studied.
  • Arterial blood gas analysis: This is highly specialized test which measures the amount of acids, oxygen and carbon dioxide in the blood. This is only ordered for those patients who are very sick and who have some form of renal failure.
  • Complete blood counts: This is test routinely performed before surgery to look for the overall well being of the child, to rule out active infection and also to see for any anemia.
4. Ultrasonogram: This is often the first investigation for most of the Pediatric Urological disorders. We get information about how the kidney looks and if there is any swelling, pus collection, stones or other problems. It also gives information about bladder wall thickening and ureters.
5. X-ray KUB: This is a plain x-ray taken on empty stomach and after the child has passed stools in the morning. We generally prescribe some laxative at night before the x-ray to ensure that the child empties the bowels in the morning. This type of X-ray is primarily done if there is any doubt about calculi/ stones.
6. Intravenous pyelogram (IVP): In this test, a medicine is given by injection to the baby and it is filtered by kidney. As a result kidneys, ureters and bladder can be very well seen on a series of x-rays. Till about 15 years back, IVP was the mainstay of all urological investigations. Nowadays with the availability of Nuclear Renal Scans, IVP is not required in most of the Pediatric Urological disorders except in certain special circumstances like double ureters, ectopic ureters or stones.

7. Renal scans: These are nuclear imaging studies and are very safe and accurate for Pediatric Urological disorders. There are further 3 types of these:

  • Diuretic Renal scans: These are primarily done to rule out obstruction at Pelvi-ureteric or Vesico-ureteric junction in a child with hydronephrosis. Additionally, information about the function of each kidney can be gathered. There are 3 agents which can be used for a diuretic renal scan- DTPA or MAG3 or LLEC. All three are good but LLEC is supposed to be the best as the image quality is the best.
  • DMSA scan: This scan is done to ascertain whether the kidney is involved in urinary infection or done to look for any scarring of the kidney post infections. This test also gives a very precise idea about the relative kidney function on either side.
  • Direct radionuclide cystogram (DRCG): This test is done to diagnose Vesico-ureteral reflux (VUR) in a child.
8. Micturating Cystourethrogram (MCU) or Voiding Cystourethrogram (VCUG): In this test a liquid medicine is put into the bladder via a thin catheter and the child is asked to pass urine on the x-ray table while the x-rays are taken. This test is the gold standard for diagnosing Vesico-ureteric reflux (VUR) and lower urinary tract abnormalities such as posterior urethral valves. This test has to be done by an experienced Pediatric Urologist/ Pediatric Radiologist otherwise the results may not be valid. There are also chances of infection so after the test a mild antibiotic is given for 3-5 days.
9.Urodynamic Studies: Urodynamic studies (UDS) are vital studies for understanding bladder function. A small double lumen catheter is inserted in bladder under aspetic precautions. Through one channel saline is infused and through second channel a transducer measures the changes in bladder pressures. In addition a needle may be inserted into sphincter muscles to see activity of sphincter muscles (muscles which contorl passage of urine). This gives a comprehensive idea about the bladder function and is especially used in children with spinal abnormalities, trauma, posterior urethral valves and severe dysfunctional voiding.
10. Cystoscopy: Cystoscopy means looking inside the bladder with a thin telescope. This is required for ruling out obstructions in urethra, stones and also for performing special x-ray of the kidney and ureter - called Retrograde Pyelogram. It may be combined with surgery to confirm the diagnosis and plan the procedure under same anesthesia. Cystoscopy is also done to place or remove a DJ stent. A DJ stent is plastic tube placed in ureter in cases of obstructions, stones etc. It helps in healing of the ureter post surgery.
11. MRI Scan: MRI scan of the spine may be required in cases where the nerve supply of the bladder is clinically suspected to be at fault.
12. CT scan: CT scan of the kidneys and urinary system is recommended children with renal injuries and sometimes also in children with renal stones.
 
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