Furosemide is administered during renal imaging primarily to:

Furosemide, a diuretic, is administered during renal imaging primarily to enhance the ability to evaluate the urinary collecting system, specifically for ruling out ureteropelvic obstruction. The mechanism behind this is that furosemide increases urine flow by promoting diuresis. In cases of urinary obstruction, the kidney might not appropriately excrete urine, leading to swelling and a delay in the clearance of the radiopharmaceutical used for imaging. By administering furosemide, the imaging technologist can stimulate the kidney to excrete the radiotracer, thereby making it easier to detect signs of obstruction when comparing the function of both kidneys. This is particularly relevant when a patient has suspected obstruction, as timely and accurate diagnosis is crucial for effective treatment.

The other options primarily represent issues that are assessed by different means or would not benefit from furosemide administration in the context of renal imaging.