Patient presenting with marked loin pain, tenderness and pyrexia shows nonspecific findings on IVP but on US reveals a heterogeneous mass with posterior acoustic enhancement and central necrosis and internal debris. CT shows marginal enhancement with air densities within. The likely diagnosis is:: (A) Emphysematous pyelonephritis, (B) Pyonephrosis, (C) Renal abscess, (D) Acute pyelonephritis
Answer is C. Renal abscess Presence of air, rim enhancement on CT and posterio acoustic enhancement in a focal mass with acute clinical history is suggestive of an abscess.