Objective To explore the feasibility and value of low dose CT scan for the diagnosis of pulmonary tuberculosis.Methods 150 patients with pulmonary tuberculosis underwent three doses CT scan (standard dose:150 mA;low-dose:15 mA and 30 mA) using GE dual slices helical CT.Besides the different tube current,other scan parameters including tube voltage,scan cycle,pitch,and collimation were the same in three dose groups.The scanned extent was from apexes to bases of lung.Image quality in standard group was compared with that in other two low dose groups and analyzed statistically by three radiologists.Results CT characteristics of pulmonary tuberculosis could be detected efficiently using low dose CT scan(30 mA) program,which was no significant as compared with the CT image using standard CT sose(P＞0.05).Howere,CT scan at 15 mA obviously affected on the diagnosis for both active and inactive pulmonary tuberculosis,the difference was significant (P＜0.05).Conclusion Low dose CT scan can replace totally the standard dose CT scan in diagnosing pulmonary tubercrulosis.

Objective To explore the technique and clinical value of percutaneous lung puncture and injection of drug under CT-guided in the treatment of multi-drug resistant cavitary pulmonary tuberculosis(MDR-TB).Methods 84 patients of positive sputum smear with MDR-TB were undergone injecting drugs into the pulmonary cavities by percutaneous lung puncture under CT-guided.The treatments were carried out by self-made locating mark which could confirm the appropriate puncture point,puncture angle and the puncture line.Results The operations of puncture in all cases were successful,the complications included pneumothorax in 3 cases,pulmonary hemorrhage in 1 case and subcutaneous emphysema in 1 case.After treatment,the mean rate of sputum negative,improvement of pulmonary cavity and cavity closure was 91.7%,89.3% and 66.7% respectively.Conclusion The percutaneous pulmonary puncture and injection of drug under CT-guided was a simple,visualized,right localization and less complications method in the treatment of the MDR-TB.