Feasibility study on application of low tube voltage using Flash mode of DSCT in pediatric chest CT scan

TANGYan; LIUCheng; SUNCong; GUOChuan-chao; BIWan-li

Abstract：Objective To evaluate the impact of three different tube voltages on image quality and radiation dosage in pe-diatric chest examination with Flash mode (subsecond high-pitch scan mode ,HPM=3 .0) of dual-source computed tomo-graphy (DSCT ) and to analyze the feasibility of the low-voltage CT scan .Methods A total of 93 patients undergoing chest scans with Flash mode of DSCT were prospectively enrolled in this study and divided into three groups equally ac-cording to different tube voltages (group 1 :80 kV ,34 cases ;group 2:100 kV ,29 cases ;group 3 :120 kV ,30 cases) . The image quality was evaluated by two radiologists using 4-point scores independently .Image attenuation and noise were measured .Signal-to-noise-ratio (SNR) and effective dose were calculated .The effective mAs ,CTDlvol and DLP were re-corded .Results The average image quality score of the three groups was (3 .12 ± 0 .640) ,(3 .69 ± 0 .471) and (3 .80 ± 0.407) .The average SNR was (4 .25 ± 0 .945) ,(5 .46 ± 1 .790) and (5 .88 ± 1 .665) .There were significant differences in score and SNR between group 1 and 2 ,group 1 and 3 ( P<0 .05) .There was no difference between group 2 and 3 ( P>0 .05) .The average CTDlvol was (1 .05 ± 0 .056) mGv ,(2 .14 ± 0 .306) mGv and (2 .63 ± 0 .697) mGv .The average ED was (0 .69 ± 0 .086) mSv ,(1 .36 ± 0 .250) mSv and (1 .84 ± 0 .808) mSv .There were significant differences in CTDlvol and ED among three groups ( P <0 .05) .Conclusion Flash mode of DSCT under 100 kV has comprehensive advantages in reducing radiation dose while ensuring high image quality ,and is of great clinical application value in the pediatric chest CT scan ,especially in the observation of fine structures ,such as small airways ,interstitial tissues ,and so on .