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': 'Most impoant investigation for posterior urethral valve: March 2011 \nSelect and explain. \nA. Urethroscopy, B. IVP, C. Retrograde cystogram, D. Micturating cystogram (MCU)', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. D: Micturating cystogram (MCU) Micturating cystography is mainly done to assess urethra for any outflow obstruction and stress incontinence Also done to demonstrate vesico-ureteric reflux especially in children Radiological signs of urinary tract: Bilateral spider leg pattern: Polycystic kidney Thimble bladder: Chronic TB Golf hole ureter: Tb urinary bladder Rim sign: Hydronephrosis Adder head/ cobra head appearance: Ureterocoele', 'role': 'assistant'}]