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': 'A dense renogram is obtained by \nSelect and explain. \nA. Dehydrating the patient, B. Increasing the dose of contrast media, C. Rapid (Bolus) injection of dye, D. Using non ionic media', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Rapid (Bolus) injection of dye Dense nephrogram or intensified renal images are obtained (iatrogenically) by - - Rapid/bolus injection of same contrast dose concentration (preferred method)(2. - Increased contrast concentration is less preferred than rapid injection method. The quantity that can be used safely depends on weight & hydration of patient. - Abdominal (ureteric) compression may be used to temporarily obstruct the upper urinary tract but is demanding. - Dehydration method used in past is not used now b/o more chances of precipitation of proteins in renal tubules, obstruction, oliguria & anuria.', 'role': 'assistant'}]