A 74 year old woman was admitted to hospital as an emergency with a 24 hour history of general malaise and intermittent vomiting. On examination she was unwell and pyrexial with a temperature of 38°C. A dipstick of her urine was positive for both protein and blood. A full blood count showed her to be anaemic with a haemoglobin of 10.0 g/dl with a mean corpuscular volume of 80 cm a white cell count of 37.7 (90% neutrophilia), and normal platelets. Baseline urea was 27 with a creatinine level of 369. The results of a midstream urine sample showed an Escherichia coli urinary tract infection sensitive to cephalexin and trimethoprim.
Her renal function showed little improvement after hydration and a 24 hour urine collection showed a reduced glomerular filtration rate of 35 ml/min. On the advice of the radiologists an initial abdominal ultrasound was followed by an abdominal computed tomography