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 2 year old boy suffering from leukaemia, following are the X-ray finding – a) Osteolytic lesion in flat bonesb) Metaphysial osteoporosisc) Periosteal new bone formationd) Osteosclerosis of long bonee) Transverse line of dark band below the growth plate \nSelect and explain. \nA. bce, B. acde, C. abcd, D. abde', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Leukemia\n\nDark bands above the metaphysis called Growth Arrest Lines. These translucent transverse metaphyseal bands are the earliest & characteristic findings.\nMetaphyseal lucencies affects maximum growth.\nCharacterstically, there are zones of rerefaction with delicate subperiosteal new bone formation in the metaphysial regions of femur, humerus or spine and pelvis.\nX-ray reveals subepriosteal and subepiphyseal resorption of bones.\nOsteolytic lesions seen in half of the cases and is commonest in shaft of long bones. But any bone can be involved.\nOsteoblastic lesions are rare, occur in metaphysis → Metaphysial osteosclerosis.\nALL may show following features on X-ray.\n\tPeriosteal reaction (periosteal new bone formation)\n\tMetaphyseal cortical erosions\n\tAltered medullary trabeculations, subepiphyseal bone resorption.', 'role': 'assistant'}]