<prompt> 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:TB kidneyXanthogranulomatous pyelonephritisChronic pyelonephritisEmphysematous pyelonephritis  <response>: 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. 