Renal infarction due to acute renal artery occlusion. (A) An initial nephrotomogram demonstrates a thin cortical rim surrounding the right kidney (arrows), reflecting viable renal cortex perfused by perforating collateral vessels from the renal capsule. (B) Four months later, a repeat nephrotomogram shows a marked decrease in the size of the atrophic right kidney (arrowheads).
Imaging Findings :
Global shrinkage of the kidney with absent opacification. There may be a peripheral rim of opacified cortex during the nephrogram phase (probably reflects viable renal cortex perfused by perforating collateral vessels from the renal capsule).
NOTE : Renal occlusion is most commonly secondary to an embolism from the heart. A decrease in renal size is detectable within 2 weeks and reaches its maximum extent by 5 weeks. Compensatory enlargement of the contralateral kidney (in individuals young enough to provide this reserve).