Editing Upper Urinary Tract Trauma (section)

==== Imaging ====

===== Indications =====
* '''<span style="color:#ff0000">[https://pubmed.ncbi.nlm.nih.gov/33053308/ 2020 AUA Urotrauma Guidelines]'''
**'''<span style="color:#ff0000">Indications for imaging (contrast enhanced CT with immediate and delayed films) in stable trauma patients (5):''' 
**# '''<span style="color:#ff0000">Gross hematuria''' 
**# '''<span style="color:#ff0000">Microscopic hematuria and systolic blood pressure < 90mmHG'''
**# '''<span style="color:#ff0000">Mechanism concerning for renal injury (e.g., rapid deceleration, significant blow to flank)'''
**# '''<span style="color:#ff0000">Physical exam findings concerning for renal injury (e.g. rib fracture, significant flank ecchymosis)''' 
**# '''<span style="color:#ff0000">Penetrating injury of abdomen, flank, or lower chest''' 
*** '''<span style="color:#ff0000">Generally, children can be imaged using the same criteria as adults. Children, however, often do not exhibit hypotension as adults do.'''

===== Modality =====
* '''<span style="color:#ff0000">CT abdomen/pelvis with IV contrast (with immediate and delayed images) should be performed when there is suspicion of renal injury''' (AUA)
** In children, ultrasound may be used, although CT is preferred
** In rare cases where the patient is taken to the operating room without preliminary CT scan and surgeons are considering renal exploration or nephrectomy, an intraoperative one-shot IVP (2 mL/kg IV bolus of contrast with a single image obtained 10-15 minutes later) may be used to confirm that a contralateral functioning kidney is present
** '''<span style="color:#ff0000">Major limitation of CT scan in renal trauma: inability to adequately define a renal venous injury adequately.''' 
*** '''<span style="color:#ff0000">A medial hematoma strongly suggests a venous injury, however, there is no imaging modality which can accurately diagnose a venous injury'''

===== Findings =====
*'''<span style="color:#ff0000">CT findings suspicious for significant renal injury include (6):''' 
*# '''<span style="color:#ff0000">Medial laceration'''
*# '''<span style="color:#ff0000">Medial hematoma (vascular pedicle injury)'''
*# '''<span style="color:#ff0000">Medial urinary extravasation (renal pelvis or ureteropelvic junction injury)'''
*# '''<span style="color:#ff0000">Hematoma > 3.5cm'''
*# '''<span style="color:#ff0000">Lack of contrast enhancement of the parenchyma (main renal arterial injury)'''
*# '''<span style="color:#ff0000">Active intravascular contrast extravasation (arterial injury with brisk bleeding)'''
[[File:Leftrenalarteryinjury.png|center|thumb|600x600px|Axial CT scan with contrast, red arrow showing left renal artery injury with extravasation. [[commons:File:Leftrenalarteryinjury.png|Source]]]] 

* '''<span style="color:#ff0000">Differential diagnosis of fluid collections seen on serial imaging for renal trauma (3):'''

# '''<span style="color:#ff0000">Hematoma''' - density is almost always > 30 HU
# '''<span style="color:#ff0000">Urinoma''' - density ranges from 0-20 Hounsfield units (HU)
# '''<span style="color:#ff0000">Abscess''' - associated with rim enhancement; perinephric abscess rarely occurs after renal injury