<prompt> A 20 years old female presented to emergency with high grade swinging fever, abdominal tenderness and flank mass. On CT there was collection around kidney. Antibiotics were staed but patient condition didnt improve after 48 hours. What is the next best treatment option?Percutaneous drainage under CT guidanceOpen surgical drainageNephrectomyObservation follow up  <response>: Diagnosis based on question- Perinephric Abscess. - Collection of fluid inside kidney- Pyonephrosis- Collection of fluid around kidney- Perinephric Abscess. Perinephric Abscess.- TOC for abscesses- Incision and drainage Antibiotics.- If no improvement with antibiotics as given in the question Deep seated intraabdominal abscess- Percutaneous drainage under USGCT guidance is preferred over Open surgical drainage.- Nephrectomy is not done because kidney function is not impaired in this case- Observation and follow up is not done because patient condition did not improvened 