What are the CT and MRI features of a renal pyogenic abscess?
A renal abscess is most often secondary to Gram-negative bacilli and may complicate acute pyelonephritis or bacteremia. Seventy percent or more of renal abscesses occur in diabetic patients.
On CT and MRI, an abscess is seen as a heterogeneous multiloculated cystic lesion, with thick rim enhancement and internal septal enhancement. The presence of gas in the lesion is highly specific for this diagnosis. Additional findings of coexistent acute pyelonephritis are also usually present.