Applied Research On Low Dose Of X-ray And Low Concentrative And Isotonic Contrast Medium Technology In Carotid CT Angiography Examination On Condition Of ASIR

Objective Discussion on the feasibility of low KV and low concentrative and isotonic contrast medium technology(double low technology) in carotid CT angiography(CTA) examination,and optimize the scanning scheme.Methods Two randomly selected group of patients for carotid CTA examination, respectively, for double low technology scan and conventional scanning technology comparative analysis between the two groups, image quality, the dose of X-ray and contrast medium iodine equivalent.Result Mean of subjective image quality in double low group and control group was no significant difference(t=-1.143,P>0.05);there was statistical differences of image noise in 3 parts(30%,50%,70%ASIR)between the two groups(P<0.05), the noise value of the control group was smaller, but the image noise reduced with the increasing proportion of ASIR;SNR and CNR of carotid artery bifurcation was no significant difference(P>0.05), and with the increasing proportion of ASIR,SNR and CNR increased.Effective dose in double low group and control group was significant different(t=-10.02,P<0.01), radiation dose of double low group decreased 49.63%. Iodine dosage in double low group and control group was no significant difference(t=-0.46,P>0.05), but the iodine equivalent in double low group and the control group was significant different(t=-5.62,P<0.01), iodine equivalent of double low group was reduced by 29.3%.Conclusion Under appropriate ASIR condition, the double low technology can significantly reduce the dose of X-ray and intake of iodine equivalent, at the same time the image quality can meet the requirement of diagnosis.