The Application Of IDose~4 Iterative Reconstructive Technique In The Craniocervical CT Angiography

Objective:To assess the influence of iDose4 advanced iterative reconstruction (IR) on image quality and radiation dosage in performing CT angiography of craniocervical arteries.Methods:A total of 80 patients,who were scheduled to receive CT angiography of craniocervical arteries,were randomly and equally divided into two groups with 40 patients in each group.Group A:120kV,300mAs, respectively, using filtered back projection reconstruction(Group Al)and iDose4 advanced iterative reconstruction (Group A2); Group B:100 kV,300mAs and iDose4 advanced iterative reconstruction were employed. CT image quality,including enhanced CT value of craniocervical arteries,contrast-to-noise ratio(CNR),image quality score was calculated and the results were compared between GroupAl and Group A2, GroupAl and Group B. Radiation dosage was calculated and the results were compared between GroupAl and Group B.Using paired t-test the measurement data were two-two compared.Results:Group Al image quality average score is 2.84±0.37 points, Group A2 image quality average score is 2.87±0.34 points, the difference was not statistically significant (t=-0.44, P=0.66), Group B image quality average score is 2.68±0.48 points,there was no difference statistically significant compared with Group Al(t=1.54, P=0.13). The SNR of GroupAl is (67.88±17.10), the SNR of Group A2 is (75.81±19.48), the difference was statistically significant(t=-2.40, P=0.02). The CNR of GroupAl is (57.03±15.45), the CNR of Group A2 is (63.61±17.48), the difference was statistically significant(7=-2.30, P=0.03). The SNR of Group B is (61.01 ±21.44), the difference has no statistically significant compared with Group Al(t=-1.34, P=0.19). The CNR of Group B is(52.82±19.16), the difference has no statistically significant compared with Group Al(t=-0.93, P=0.36). The effective dose of Group A1 is (10.69±0.61) mSv, the effective dose of Group B is (6.41 ±0.35) mSv, difference was statistically significant(t=-34.16, P=0.00)Conclusions:In the examination of CT angiography of craniocervical arteries, compared with filtered back projection (FBP) algorithm, iDose4 technology can obtain better image quality.By using low tube voltage technique with iDose4 iterative reconstruction, the radiation dose can be markedly reduced without degradation of image quality.