In a child, non-functioning kidney is best diagnosed by:

In order to assess function of an apparent non-functioning kidney, the best modality would be DTPA renogram. About other options: a. Ultrasonography: initial modality for imaging of the kidney and urinary tract. Good for anatomic details and not functional details of kidneys ureter and bladder. b. IVP (Intravenous pyelography) gives valuable information about renal anatomy and function. But due to the risk of anaphylaxis with the contrast material use of IVP has declined following the availability of radionuclide imaging. d. 24 hrs creatinine clearance can be calculated by collecting a timed urinary specimen and taking a blood sample around the mid-collection period. In children, in addition to problem with urine collection, this overestimates the actual GFR and can't be used to assess isolated kidney function.