Fig. 4

A 33-year-old female with nephrolithiasis and previous unsuccessful ESWL treatment 3 years earlier underwent PCNL with ureteral stenting. Preoperative unenhanced MDCT (A) showed the left kidney with moderate pelvicalyceal dilatation, a 2-cm renal pelvis stone plus two additional 8–9 mm lower calyx stones. Intractable flank and abdominal pain with laboratory signs of blood loss (6.2 mg/dl nadir haemoglobin) led to urgent contrast-enhanced multiphase MDCT hours after the procedure. MDCT (B–F) detected a fresh clot in the left pelvicalyceal system (thin arrows in B and F), thin subcapsular haematoma (arrows), massive perirenal and posterior pararenal haemorrhage (*) causing anterior displacement of spleen and kidney plus ureter medialisation (arrowheads). A focal injury at the lower renal pole (thin arrow in E) corresponded to the instrumentation access site, without signs of active bleeding and extravasated urine. Urologists opted for conservative treatment including blood transfusions. Seven days later, with improving clinical conditions, repeat MDCT (G, H) showed retroperitoneal haemorrhage (*) with well-demarcated margins and decreasing size, attenuation values and mass effect (arrowhead in G)