Abstract： Objective To study the association of magnetic resonance imaging (MRI)characteristics with prognosis of patients with intracranial tuberculosis.Methods From January 2012 to December 2016,the MR images and case records of 420 patients with intracranial tuberculosis in our hospital were retrospectively analyzed.There were 220 males and 200 females,aging 8 to 83 years,with a median age of 28.5 years.According to MRI,93 patients were classified as meningeal tuberculosis,192 patients as parenchymal tuberculosis,82 patients as mixed intracranial tuberculosis,and another 31 patients showing no obvious abnormalities while 22 patients had only leukoencephalopathy.The measurement data were analyzed by t test.Chi square test was used to count data analysis.The prognosis related factors were retrospectively analyzed by Logistic regression.P＜0.05 was regarded as statistically significant.Results The direct signs of MR imaging of meningeal tuberculosis were meningeal exudation,thickening and enhancement.Secondary changes included hydrocephalus,cerebrovascular inflammation,cerebral infarction and cranial nerve involvement.Brain parenchymal tuberculosis included brain parenchymal tuberculoma,tuberculous abscess and tuberculous encephalitis.Brain parenchymal tuberculoma showed solid nodules,with equal or slightly low signal on T1WI,high signal on T2WI,low signal on T2WI after central necrosis,high signal on T2WI during liquefaction of necrosis,homogeneous enhancement nodules on enhanced scan without necrosis,and ring enhancement nodules with necrosis.Tuberculous abscess manifested as a ring-shaped enhancement of the abscess wall with aggravated pus with limited diffusion.Tuberculous encephalitis manifested as gyrus-like high signal on T2WI,low signal on T1WI,and uneven enhancement on enhanced scan.Mixed intracranial tuberculosis had features of both meningeal tuberculosis and parenchymal tuberculosis.The Barthel scores at admission and discharge of the meningeal tuberculosis group were (53±30) and (61±28),while those of the parenchymal tuberculosis group were (77±29) and (81± 26),and those of the mixed intracranial tuberculosis group were (58±29) and (66±28).The Barthel scores at admission and discharge of the meningeal tuberculosis group and mixed intracranial tuberculosis group were significantly lower than those of the parenchymal tuberculosis group (P＜0.001).There were 151 patients with poor prognosis at discharge (Barthel score ≤60 points) and 71 patients with poor long-term prognosis (death or dysfunction after follow-up for at least 12 months).There were 35 patients who died.The poor prognosis rate at discharge,at long-term and the mortality rate of meningeal tuberculosis group were 50.5％(47/93),25.8％(24/93) and 15.1％(14/93),respectively,while those of the cerebral parenchymal tuberculosis group were 23.4％(45/192),12.5％(24/192),5.7％(11/192),respectively,and those of the mixed intracranial tuberculosis group were 47.6％(39/82),20.7％(17/82) and 7.3％(6/82),respectively.The poor prognosis rate at discharge and at long-term were higher than the cerebral parenchymal tuberculosis group(all P＜0.05).The mortality rate of meningeal tuberculosis group was higher than the cerebral parenchymal tuberculosis group (P=0.009).Logistic regression showed that peri-mesencephalic cisterns involvement(OR=2.339,95％CI 1.355-4.037,P=0.002),hydrocephalus(OR=3.896,95％CI 2.077-7.308,P＜0.001),cerebral infarction (OR=3.282,95％CI 1.615-6.670,P =0.001) were independent risk factors for poor prognosis at discharge.While hydrocephalus(OR=4.458,95％CI 2.341-8.492,P＜0.001) and cerebral infarction (OR=2.456,95％ CI 1.179-5.114,P =0.016) were independent risk factors for long-term prognosis.Hydrocephalus (OR =6.803,95％ CI 3.119-14.839,P＜0.001) was the only independent risk factor for death.Conclusions MR imaging classification of intracranial tuberculosis was correlated with clinical manifestations and prognosis of the patients.The prognosis of patients with meningeal exudation was worse than that of patients with parenchymal tuberculoma.Hydrocephalus was independently associated with the risk of death in patients with intracranial tuberculosis.