My mother Aged 58 years is suffering from kidney related ailment as per report as her creatinine and Urea levels are not normal. But her 2 CT scans have reflected nothing , PET scan is also normal. But in her urine test PUS is reflecting, what can be the possible cause for that. Because it's been more than 2 months are antibiotics courses though her condition has improved but not cured. Exact cause/source of infection is still not able to be identified.