Grade I: non-expanding subcapsular hematoma Grade II: Laceration < 1 cm. Hilum is not involved. No extravasation of urine. Grade III: Laceration > 1 cm. No extravasation of urine. Grade IV: Laceration extending into the collecting system. Hilum is involved but hemorrhage is limited. Grade V: Avulsion of hilum leading to devascularization of kidney. Kidney is completely shattered. Reference: https://www.researchgate.net/figure/AAST-Renal-Injury-Grading_tbl1_264424381 Image via: https://www.sciencedirect.com/science/article/pii/S2221618915000827