Abstract: Objective  To investigate the clinical characteristics and the diagnostic value of different imaging methods of patients with tuberculous meningitis (TBM)  in various clinical stages. Methods  Cranial CT and MRI examinations were performed on 85 patients with TBM,  of which 71 cases were performed simultaneously with cranial MRI enhancement,  and 28 cases of spinal cord MRI scan and enhanced examination were performed. The clinical staging and imaging features were analyzed in 85 patients. Results  Among  85 patients,  there were 25 cases in stage Ⅰ,  34 cases in stage Ⅱ and 26 cases in stage Ⅲ. The most common clinical features were fever,  headache,  meningeal irritation sign,  cranial nerve palsy and so on. In stage Ⅰ,  fever and  headache were the most common manifestations. Progressive stage of consciousness,  cranial nerve palsy,  hemiplegia  entered phase Ⅱ and Ⅲ. The most common imaging findings included meningeal enhancement,  cerebral parenchymal tuberculosis,  cerebral infarction. Phase I was mainly manifested as inflammatory exudation of meninges and brain parenchyma. Imaging findings of stage Ⅱ and  Ⅲ  patients were diverse,  including basement meningeal enhancement,  parenchymal tuberculosis,  cerebral infarction,  hydrocephalus,  and brain edema. There were 25 cases of abnormal signal on CT,  the positive rate was 29.41%,  which was 4% in stage Ⅰ,  29.41% in stage Ⅱ and 53.85% in stage Ⅲ. There were 54 cases of abnormal signal on MRI,  the positive rate was 63.53%,  which was 48% in stage Ⅰ,  64.71%  in stage Ⅱ  and 76.92% in stage Ⅲ. There were 58 cases of  MRI abnormalities enhanced  by cranium,  the positive rate was 81.69%,  and 15 cases of CT and MRI scan negative lesions were found. There were 10 cases of abnormal MRI scan and enhanced examination of the spinal cord,  the positive rate was 35.71%. Conclusion   The clinical manifestations of TBM are not typical. Imaging examination,  especially cranial MRI,  can clearly show various kinds of intracranial lesions in TBM,  and the positive rate increases with the increase of clinical stages. Combined with cranial MRI enhancement can significantly increase the detection rate of TBM,  which is beneficial to the early diagnosis of TBM.

Key words: tuberculous, , meningitis;signs and symptoms, magnetic resonance imaging