This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Radiology
[{'content': 'The investigation of choice for meningeal carcinomatosis in CNS is: \nSelect and explain. \nA. Enhanced MRI, B. SPECT, C. PET, D. NCCT', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. A. Enhanced MRI* Leptomeningeal carcinomatosis (LC) refers to diffuse seeding of the leptomeninges by tumor metastases.* LC occurs in 'an estimated 20% of patients diagnosed with cancer and is most commonly found in breast carcinoma, lung carcinoma, and melanoma in adults and hematogenous malignancies and primitive neuroectodermal tumor (PNET) in children.* Contrast-enhanced MRI of the brain and spine is the imaging modality of choice because of its safety, excellent contrast resolution, and multiplanar abilities.", 'role': 'assistant'}]