Influence of Diuresis Timing (F+0 Vs F-15) on 99m Tc DTPA Renography for the Diagnosis of Suspected Obstructive Uropathy in Adult Hydronephrotic Patients.

Obstructive uropathy can be defined as any blockage of urine drainage from the kidney (renal calyces or renal pelvis), ureter, or bladder. As a result of the blockage, urine backs up into the kidneys, causing dilatation of the ureter, renal pelvis, and renal calyces, which can damage the kidney if it is not treated. The appearance of dilated or enlarged renal pelvis and calyces is referred to as hydronephrosis and is a symptom of obstructive uropathy.

Diuresis renography(renal scan with using of diuretic drug such as furosemide) is non-invasive test which is based on a high endogenous rate of urine flow stimulated by the administration of furosemide. Interpretation of the test is based on the rate of washout of the radiopharmaceutical from the collecting system in the upper urinary tract.

A number of different protocols exist in terms of the timing of furosemide injection, (F+0) protocol in which furosemide is injected at the same time of radiotracer administration &( F - 15)protocol in which furosemide is administered 15 min before tracer administration.