Renal cortical necrosis occurs as a result of severe systemic illness in a variety of settings and can result in permanent renal impairment. The condition is usually bilateral but may occasionally be unilateral.
On this page:
Pathology
Etiology
-
severe hemodynamic shock
-
hemorrhagic shock
postpartum hemorrhage: most common cause, and most often associated with placental abruption in the third trimester 3
traumatic blood loss
venom toxin
transfusion reaction
severe dehydration
acute aortic dissection
-
Radiographic features
CT
Contrast-enhanced CT demonstrates a non-enhancing renal cortex and a normal enhancing renal medulla (reverse rim sign). A very thin rim of contrast enhancement (cortical rim sign) may persist and should not be mistaken for adequate perfusion.
Global atrophy of the kidneys occurs within a few months, leading to small smooth kidneys.
Eventually dystrophic calcification of the renal cortex may be seen (cortical nephrocalcinosis), sometimes referred to as “tramline” calcification.
MRI
Low signal intensity on both T1 and T2 weighted sequences affecting the inner renal cortex and the columns of Bertin is the major characteristic finding of renal cortical necrosis 1.
Additional features include:
swelling of both kidneys
corticomedullary differentiation seen better on T2-weighted images instead of T1-weighted images
Note that the cortical rim sign can persist in renal cortical necrosis because of its separate capsular blood supply.
Differential diagnosis
other causes of low signal intensity renal parenchyma on MRI