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': 'The radiographic finding of the left maxilla indicate towards: \nSelect and explain. \nA. Fibrous dysplasia, B. Paget’s disease, C. Hyperparathyroidism, D. Osteoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Imaging Features:\nLocation:\nFibrous\xa0dysplasia\xa0involves\xa0the\xa0maxilla\xa0almost\xa0twice\xa0as often as the mandible and occurs more frequently in the posterior aspect. Lesions more commonly are unilateral, except for very rare extensive lesions of the maxillofacial region that are bilateral.\nPeriphery:\nThe\xa0periphery\xa0of\xa0fibrous\xa0dysplasia\xa0lesions\xa0most\xa0commonly is ill-defined, with a gradual blending of normal trabecular bone\xa0into\xa0an\xa0abnormal\xa0trabecular\xa0pattern.\xa0Occasionally,\xa0the boundary between normal bone and the lesion can appear sharp and even corticated, especially in young lesions.\nInternal\xa0Structure:\nThe\xa0density\xa0and\xa0trabecular\xa0pattern\xa0of\xa0fibrous dysplasia\xa0lesions\xa0vary\xa0considerably.\xa0The\xa0variation\xa0is\xa0more\xa0pronounced in the mandible and more homogeneous in the maxilla. The internal aspect of bone may be more radiolucent, more radiopaque, or a mixture of these two variations compared with normal bone. The internal density is more radiopaque in the maxilla and the base of the skull. Early lesions may be more radiolucent than mature lesions.\nKey Concept', 'role': 'assistant'}]