Objective To explore the superiority of dual-phase contrast-enhancement multi-slice computed tomography (MSCT) in observing intracranial tuberculosis.Methods Thirty patients with intracranial tuberculosis,admitted to our hospital from January 2003 to November 2011,were chosen in our study; regular 16-slice spiral CT scan was performed,and then,dual-phase MSCT was performed as follows:contrast-enhanced scan was performed 25 seconds after arrival of contrast material on vascular phase,and 5 minutes after that (lag phase),conventional scanning was performed.According to the different lesions and morphologies of the tuberculosis,they were divided into three types:meningeal thickening,meningeal tuberculoma and parenchymal tuberculoma; the lesion sizes and edge definition and the relationship of the lesions with the surrounding vascular lesions in these three types were scored and calculated,and the differences of the image quality were compared at the vascular phase and lag phase.Results A total of 526 lesions in 30 patients were found,including 22 with meningeal thickening,235 with meningeal tuberculomas/tubercles,and 269 with parenchymal tuberculomas/tubercles.As compared with these three types at the vascular phase (0.36±0.49,0.36±0.52 and 0.41±0.53; 0.00,0.27±0.45 and 0.12±0.32; 1.09±0.68,1.22±0.74 and 1.27±0.75),these three types at the lag phase had significant differences in the scores of lesion sizes (1.64±0.58,1.64±0.58 and 1.59± 0.60) and lesion edge definition (2.00,1.73±0.49 and 1.88±0.34) and the relationship of the lesions with the surrounding vascular lesions (1.82±0.39,2.00±0.06 and 2.00±0.06,P＜0.05).Conclusion Images in the lag phase have advantages on diagnosis of intracranial tuberculosis.