Application Of Low-dose Chest Spiral CT In Screening Pulmonary Nodules In Healthy Population

Objective:(1)Comparative analysis between DR and Low Dose CT(LDCT)for the detection rate and nodule size distribution ratio of pulmonary nodules in healthy population(general physical examination).(2)Comparative analysis of normal dose CT and low-dose CT scan detection rate of lung nodules,effective radiation dose,nodule size distribution,nodule diagnosis distribution,nodule type distribution and image quality in asymptomatic healthy population.(3)Comparative analysis of detection rate of lung nodules,effective radiation dose,nodule size distribution,nodule diagnosis distribution,nodule type distribution and image quality in asymptomatic healthy population the asymptomatic healthy examination population using Low dose CT scan between the Dual-source CT and 256-row CT.Materials and methods: In this study,67,293 DR cases of routine health examination from January 2013 to December 2013 in the routine physical examination center of the First Affiliated Hospital of Guangxi Medical University was collected(among which: 47002 were male and 20291 were female,aged 16-98 years,mean age 42.14 ± 14.65 years old).3228 cases of dual-source CT examination of the chest from January 2013 to May 2014 of healthy people was collected(among which 2010 were male,1218 were female,aged 18-97 years,mean age 51.12±12.87 years old).This data was divided into low-dose group and normal-dose group according to mAs value(i.e.LDCT ?50mAs and Normal dose CT>50mAs).Low dose CT cases of healthy people were collected from January 2016 to March 2016 for dual-source CT chest examination(there were 743 cases among which 419 were male,324 were female,aged 21-91 years,mean 57.18±12.99 years)and from January2017 to March 2017 for 256 row chest CT(there were 779 cases among which 517 were male,262 were female,aged 17-87 years,mean 48.56±11.73 years).Result:(1)There was a statistically significant difference in the detection rate and nodule size distribution ratio of pulmonary nodules between DR and LDCT groups(P<0.05).(2)There was a statistically significant difference in the detection rate of pulmonary nodules and effective radiation dose between LDCT and normal dose groups(P<0.05).LDCT had higher detection rate and lower effective radiation dose.There was no significant difference in nodule size distribution,nodular diagnosis distribution,nodule type distribution and image quality between LDCT and normal dose CT(P>0.05).(3)There was no statistically significant difference in general physical examination of healthy population between 256-row CT and dual-source CT for detection of pulmonary nodules,effective radiation dose,nodule size distribution,nodule diagnosis distribution and image quality(P>0.05).Conclusion:(1)DR has poor efficacy in detection of lung nodules in healthy populations.The detection rate and the ability to detect small nodules are far less than LDCT.(2)LDCT can ensure the quality of images while reducing the tube current(thus reducing the radiation dose),and has a high detection rate of lung nodules in healthy people.The nodule size distribution,nodule diagnosis distribution,nodule type distribution and image quality were not statistically different from the normal dose CT group,indicating that LDCT has the diagnostic efficacy of normal dose CT.(3)The difference in nodule detection rate,nodule size distribution,nodule diagnosis distribution,nodule type distribution,effective radiation dose and image quality between 256-slice CT and dual-source CT in healthy subjects,was not statistically significant.Hence,both 256-row CT and dual-source CT have the similar lung nodule detection rate,diagnostic efficiency,effective radiation dose and image quality.