Abstract: Abstract：Objective  To evaluate the diagnostic value of multi-slice spiral CT(MSCT) for sputum smear- and culture-negative pulmonary tuberculosis with solitary node shown in chest digital radiography(DR) X-ray. Methods   Solitary node shown in chest DR X-ray and MSCT among 180 cases with smear- and culture-negative pulmonary tuberculosis were analyzed retrospectively and solitary node shown in different section thickness of MSCT and chest DR X-ray were compared. Results   Chest DR X-ray showed cavities in 6 cases and 5 mm section thickness MSCT showed in 15 cases (χ²＝4.096，P=0.043) and 1 mm section thickness MSCT in 16 cases (χ²＝4.841，P=0.028). Satellites were seen in 50 cases with 5 mm section thickness MSCT(χ²＝65.616，P=0.001) and in 55 cases with  1 mm section thickness MSCT(χ²＝68.882，P=0.001), but no satellite was observed in chest DR X-ray. Calcification  was found in shadow among 120 cases with 5  mm section thickness multiplanar reconstruction MSCT(χ²＝116.883，P=0.001) and among 140 cases with 1mm section thickness multiplanar reconstruction MSCT(χ²＝162.000，P=0.001). However, there were only 20 cases found calcification in shadow with chest DR X-ray. There were also statistical differences in calcification of shadow between  5 mm and 1 mm section thickness multiplanar reconstruction MSCT(χ²＝5.538，P=0.019).  Enlarged lymph nodes were observed in 30 cases with  5 mm (χ²＝33.750，P=0.001)or 1 mm(χ²＝33.750，P=0.001) section thickness multiplanar reconstruction MSCT. There was no enlarged lymph node observed in Chest DR X-ray. Tree-in-bud sign was not shown with Chest DR X-ray in all patients and was shown with 1 mm MSCT among 10 patients (χ²＝9.907，P=0.007). Ground-glass opacities was not shown with chest DR X-ray in all patients and was shown with 1 mm MSCT among 10 patients(χ²＝15.882，P=0.001). Conclusion   MSCT is better in diagnosis of smear- and culture-negative pulmonary tuberculosis with solitary nodes than chest DR  X-ray. 

Key words: Tuberculosis,pulmonary/radiography, Tomography,spiral computed