This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Radiology
[{'content': 'Spider leg appearance is found on: September 2012 \nSelect and explain. \nA. Polycyctic kidney, B. Pyelonephrits, C. Hydronephrosis, D. Renal aery stenosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A i.e. Polycystic kidney Urinary system: Radiological signs and conditions Flower vase appearance: Horse shoe kidney Fish hook bladder: BPH Dropping flower sign: Ectopic ureter Cobra head appearance: Ureterocoele Adder head appearance: Ureterocoele Rim sign: Hydronephrosis Crescent sign: Hydronephrosis Golf hole bladder: TB urinary bladder Thimble bladder: Chronic TB Bilateral spider leg pattern: Polycystic kidneys Bilateral spider leg pattern: Polycystic kidney Thimble bladder: Chronic TB Rim sign: Hydronephrosis Cobra head appearance: Ureterocoele Adder head appearance: Ureterocoele', 'role': 'assistant'}]