Learning Radiology xray montage
 
 
 
 
 
 

Renal Trauma
 Renal Fracture and Renal Laceration
  • Incidence

    • Up to 10% of injuries coming to emergency room with blunt trauma

  • Causes

    • Motor vehicle accident
    • Contact sports
    • Falls and fights
    • Less often penetrating wounds

  • Mechanism

    • Direct blow (>80%) frequently compressed and often lacerated by lower ribs
    • Acceleration-deceleration injuries can produce renal artery tears
  • Associated with other organ injury in 20% of cases

  • Signs and symptoms

    • >95% hematuria
      • 25% of patients with gross hematuria have significant injuries
      • But, 24% of patients with renal pedicle injury have no hematuria
      • Only 1-2% with microhematuria have a severe renal injury

  • Types of injuries

CT Classification of Renal Trauma

CT Grade

Injury

Usual Treatment

Grade I

Superficial cortical laceration, contusion and/or perirenal hematoma

Observation

Grade II

Deep corticomedullary laceration involving the collecting system

Observation or surgery

Grade III

Renal crush injury and/or main vascular pedicle injury

Surgery

Grade IV

Injury of the renal pelvis or the ureteropelvic junction

Surgery

 

    • Renal contusion
    • Superficial cortical laceration (75-85%)
    • Small cortical laceration without calyceal disruption
    • Complete cortical laceration
      • Fracture communicating with calyceal system (10%)
        • Extraluminal contrast material
        • Separation of renal poles or fracture

Contrast-enhanced CT of the mid-abdomen reveals a linear zone of low attenuation
through the left kidney with surrounding perinephric stranding characteristic of a deep renal laceration

    • Crush injury
      • Usually involves injury to the renal vascular pedicle (5%)
      • Multiple separate renal fragments
        • Lack of enhancement of part or all of kidney
      • Extraluminal contrast material
    • Subcapsular hematoma

  • Imaging Findings

    • Focal patchy areas of decreased enhancement / striated nephrogram = contusion
    • Irregular linear hypodense parenchymal areas = renal laceration
    • Laceration connecting two cortical surfaces = fracture
    • Multiple separated renal fragments ± perfusion = shattered kidney
    • Superficial crescentic hypodense area compressing adjacent parenchyma = subcapsular hematoma
      • Subcapsular / perinephric hematoma usually proportional to extent of injury
    • Wedge-shaped perfusion defect = segmental arterial injury
    • Diffuse non-perfusion of kidney = devascularized kidney
    • Persistent nephrogram on delayed scans = renal vein thrombosis

 

 

Injury

How do you recognize it

Contusion (75-80%)

focal patchy areas of decreased enhancement

Laceration

irregular linear hypodense parenchymal areas

Fracture

laceration connecting two cortical surfaces

Crush injury

multiple separated renal fragments ± perfusion

Calyceal or pelvic injury

Extraluminal contrast

Vascular pedicle injury

Wedge-shaped or diffuse non-perfusion of kidney

Subcapsular hematoma

superficial crescentic hypodense area compressing adjacent parenchyma