Urinary: Perfusion/Vascular Flashcards
Hypertension s/p renal biopsy
Page kidney (hypertension secondary to a sub capsular hematoma compressing the kidney)
Note: This occurs because the renal capsule does not expand.
Delayed vs persistent nephrogram
A delayed nephrogram usually only affects one kidney (due to pressure: obstruction, sub capsular hematoma, renal vein thrombosis, etc.)
A persistent nephrogram is usually bilateral and can persist for hours (seen with hypotension/shock and acute tubular necrosis)
Wedge shaped renal hypodensity…
- Think renal infarction (if there is a rim of cortical enhancement)
- Think pyelonephritis (if hypodensity extends through the cortex to the edge, no “cortical rim” sign)
Cortical rim sign
A rim of enhancing tissue peripheral to a wedge-shaped renal hypodensity, suggesting infarction rather than pyelonephritis (due to the dual blood supply of the cortex)
Note: The cortical rim sign takes 8 hours-multiple days to show up and will not be present immediately after infarction.
Reversed diastolic flow in the renal artery and absent venous flow…
Renal vein thrombosis
Common causes of renal vein thrombosis
- Nephrotic syndrome (most common in adults)
- Dehydration
- Indwelling umbilical venous catheters (neonates)
CT findings of renal vein thrombosis
Unilateral enlarged kidney with a delayed nephrogram
Acute cortical necrosis
Note: Relative hypodensity of the renal cortex (“reverse cortical rim” sign).
Common causes of acute cortical necrosis
Severe hypovolemia:
- Shock
- Intravascular hemolysis
- OBGYN complications (e.g. placental abruption)