This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory System, Subject name: Radiology
[{'content': 'Investigation of choice in bronchiectasis \nSelect and explain. \nA. MRI, B. HRCT, C. bronchoscopy, D. chest x-ray', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans: b (HRCT)Second investigation of choice (earlier): Bronchography (not Bronchoscopy)HRCT signs:Honeycomb patternTram-track patternGrape cluster patternTooth paste patternSignet ring patternVery importantSome Investigations of choice:Bronchiectasis :HRCTRenal TB (early) :IVPRenal TB (advanced) :CT>IVPRenal calculus :Non contrast Helical CT scanDental pathology andTM joint pathology :pantamogramPregnant lady with upper abdominal mass :MRIPosterior urethral valve and VUR :MCU (Micturating cystourethrogram)Osteoporosis :DEXA', 'role': 'assistant'}]