This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Plain Film Radiography, Fluoroscopy, and Tomosynthesis, Subject name: Radiology
[{'content': 'Which does not form the border of heart in PA view of a chest X-ray? \nSelect and explain. \nA. Right atrium, B. Right ventricle, C. Aortic arch, D. Left Ventricle', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans- B Ref: Nelson\'s Textbook of Pediatrics 18th edition: page no 1865 Explanation: In a CXR PA view the Left border of Heart is formed by: "A.M.L" Aortic arch Main pulmonary artery Left pulmonary artery, Left atrial appendage, Left ventricle Right border of Heart is formed by: "S.I.R" SVC IVC Right Atrium Abnormal cardiac silhouettes "Boot-shaped" heart seen in cyanotic tetralogy of Fallot "Egg-shaped" heart seen in transposition of the great arteries. "Snowman" sign or Figure of \'8\' appearance seen in total anomalous pulmonary venous return (supracardiac TAPVC)', 'role': 'assistant'}]