This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdominal Radiography, Subject name: Radiology
[{'content': 'IOC for neonatal hypertrophic pyloric stenosis: \nSelect and explain. \nA. X Ray, B. CT scan, C. MRI, D. Ultrasound', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (d) UltrasoundRef: SRB Manual of Surgery 4th ed. 1877* Ultrasound abdomen is the investigation of choice for diagnosing hypertrophic pyloric stenosis.* It is reliable, highly sensitive, highly specific, and easily performed.* The mandatory measurements include pyloric muscle thickness and pyloric channel length.* Muscle wall thickness 3 mm or greater and pyloric channel length 14 mm or greater are considered abnormal in infants younger than 30 days.', 'role': 'assistant'}]