Fig. 1

The preoperative abdominal non-contrasted computed tomographic (NCCT) and plain kidney-ureter-bladder (KUB) films of six enrolled cases with complex kidney stones (CKS). (A) Case 3, a partial staghorn stone with multiple stones in medium calyceal diverticulum, was assessed as Guy’s Stone Scores (GSS) grade III; (B) Case 11, multiple stones in the renal pelvis and lower calyceal diverticulum, was assessed as GSS grade III; (C) Case 8, a partial staghorn stone with multiple stones in lower calyceal diverticulum, was assessed as GSS grade III; (D) Cases 6, a stone in the pelvis of a solitary ectopic thoracic kidney (ETK) with a severe congenital scoliosis deformity, was assessed as GSS grade IV; (E) Case 9, multiple stones in the pelvis and lower calyceal diverticulum of an ETK with a severe rachiterata caused by spinal tuberculosis, was assessed as GSS grade IV; (F) Case 4, a complete staghorn stone, was assessed as GSS grade IV. Unclear high-density shadows of stones are denoted by black arrows in plain KUB films. S = stone