Investigations :- are done based on suspicion and the most important 2 investigations are Ultrasound(USG) of the kidneys, ureters, and bladder; followed by a Voiding Cysto Urethrogram(VCU).

The USG will show the shape, size thickness of the kidneys, presence of dilatation of the ureters, and the bladder wall thickness, residual urine etc.

The VCU is the next investigation wherein a small tube is passed into the urethra of the child upto the bladder and the bladder is filled with a contrast liquid that is seen as white on a x ray picture. When the bladder is full one x ray is taken to look for the shape, size of the bladder, any reflux is present can also be seen and graded. Next the tube is removed from the bladder and the child is asked to pass urine and a second x ray is taken as the child is passing urine. This will show the presence of reflux if it occurs only during straining; it will also show the shape and size of the urethra, any obstruction at the bladder neck or in the urethra that may be the primary cause.

Neither of thee investigations tells us the individual function of the kidneys which is essential to know before therapy is begun. This will act as a baseline for later studies to show improvement in function after proper therapy or may show no improvement that may indicate permanent damage has already occurred. This can be done by doing a Radio Nuclear study called DMSA Scan of the kidneys. Here, the radioactive material is injected into the child intravenously and the pictures are taken at intervals and charted. This investigation will tell the individual function of each kidney( normal should be 50%). This will also show non functioning areas of the kidney as "cold" areas suggesting damage to that part of the kidney. The more the cold areas, the worse is the prognosis, and lower the percentage function of the kidney, worse is the prognosis. Serial Scans will show improved function if the treatment is successful and others may show no change in percentage or may even show falling percentage leading to a renal failure.