Sheela, a middle aged diabetic female presented with flank pain and fever. On USG, the kidney was irregular and showed fat density lesion with calculi. The diagnosis is most probably:

Hints in the question-- Diabetic- Middle aged Female- Flank pain- Fever- Fat density lesion- Associated with calculi. Xanthogranulomatous (due to presence of fat) pyelonephritis (infection with kidney etiology)- It is more common in females as they are more prone to Struvite stone formation- Causative Organism - Proteus Emphysematous pyelonephritis- Most common causative organism- E. coli - Presence of ring of air around kidney or within kidney.