Imaging in renal trauma

Table 1 American Association for the Surgery of Trauma grading

Grade	Type of injury	Injury description
I	Contusion	Microscopic or gross hematuria, normal urological studies
	Hematoma	Nonexpanding subcapsular hematomas with no parenchyma laceration
II	Hematoma	Nonexpanding perinephric (perirenal) hematomas confined to the retroperitoneum
	Laceration	Superficial cortical lacerations less than 1 cm in depth without pelvicalyceal system injury or urinary extravasation
III	Lacerations	Deeper lacerations, more than 1 cm in depth without Pelvicalyceal system injury
IV	Laceration	Renal lacerations extending through the renal cortex, medulla and collecting system
		Injuries involving the main renal artery or vein with contained hematoma
	Vascular injury	Segmental infarctions without associated lacerations
V	Laceration	Completely shattered kidney Ureteropelvic junction injury
	Vascular injury	Complete laceration (avulsion) or thrombosis of the main renal artery or vein that devascularizes the kidney

Advance one grade for bilateral injuries up to Grade III. Expanding subcapsular hematomas that compress the kidney may be considered as Grade IV injuries.