Study of pulmonary radiation low-dose spiral CT

Objective:The purpose of this study is to evaluate low-dose helical CT in chest compared with conventional helical CT.Methods:Patients were undergone the conventional spiral CT scan.The scan parameters were 120kV,thickness 10mm,interval 10mm and pitch 1.5.Different thickness (5mm,10mm) were adopted and different mAs were used (200mAs,40mAs,30mAs,20mAs,10mAs).The weighted CT dose index (CTDIw) and milliampere seconds (mAs) were recorded.The data were analyzed with the different statistical methods.There was signifie difference (P0.05).Results:There was much nore significant difference about the data of the CTDIw and the mAs between the conventional helical CT group and rest groups (40mA,30mA,20mA,10mA) (P0.05).Compared to the standard group (200mAs),mean value of the mAs and CTDIW of the other groups (40mAs,30mAs,20mAs,10mAs) reduced 80%,85%,90%,95% respectively.Conclusion:The weightes CT dose is reduced 90 per cent.20mA is the best dose of lung scanning.With the lower radiation and the stronger sensation and the better price performance ratio,low-dose spiral CT is worthy to be used widely.