Fig. 1
From: Rigid ureteroscopic lithotripsy in the lateral decubitus position for upper urinary tract stones
Renal pelvis shown on computed tomography (CT) images for different body positions. A In the supine position, the renal pelvis forms an angle that tends to guide the stone into the kidney if loosened during the operation. B In the lateral position, the left ureteropelvic junction moves to the lowest point. The stone tends to not migrate into the kidney and would fall back if it does