text: Intravenous pyelography is considered the best initial test.
option_0: Horseshoe kidney dignostic study of choice
option_1: Renal oncocytoma diagnostic study of choice
option_2: Horseshoe kidney other imaging findings
option_3: Wilms' tumor diagnostic study of choice
option_4: Renal oncocytoma other diagnostic studies
option_5: Adrenal insufficiency diagnostic study of choice
option_6: Hydronephrosis diagnostic study of choice
option_7: Renal oncocytoma other imaging findings