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': 'Papillary necrosis features are all except: \nSelect and explain. \nA. Egg in cup, B. Hyperdense nephrogram, C. Calyceal horns, D. "Ring shadows"', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Hyperdense nephrogram Characteritic IVP features of papillary necrosis include ball in cup or egg in cup configuration, signet ring sing or ring shadow of papilla, lobster clew sign, club shaped (saccular) calyxQ, amputated calyces, multiple cavities, nonopaque filling defects and diminished density of contrast material in nephrogramQ.', 'role': 'assistant'}]