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': 'True about OCG is – a) First done by Graham Cole in 1942b) Dye ingested at rate of 1 ml/kgc) USG has replaced itd) Dye used is telepaque \nSelect and explain. \nA. ab, B. cd, C. bd, D. ac', 'role': 'user'}, {'content': 'Answer: B \nExplanation: OCG was introduced by Graham and Cole in 1924 (not in 1942).\nTwo doses of 3 gm of dye is given --> first dose 14 hours, and second dose 3-4 hours prior to post-contrast examination.\nOCG has largely been replaced by USG\nDye most commonly used is Na/Ca Ipanoic acid (Telepaque).', 'role': 'assistant'}]