The qualitative I-131 Hippuran renogram. A potential problem

The I-131 Hippuran renogram time activity curve is usually generated by assigning computer assisted regions of interest over each kidney. Qualitative whole kidney renogram curves can be misleading when there is a nonobstructed but dilated collecting system or asymmetrical excretion of the tracer from the renal collecting system. This problem can be minimized by generating an additional renogram curve from a region of interest assigned over each renal cortex.