Value Of Energy Spectrum CT Technique In Head And Neck Angiography

Objective:The energy spectrum CT head and neck CTA examination with 80-140 kVp instantaneous switching technique was used to find the best single-energy image,and the value of energy spectrum CT in head and neck CTA compared with conventional CT was evaluated.Method:Sixty patients underwent CTA examination of the head and neck energy spectrum.The energy spectrum analysis software was used to generate 6 sets of single-energy images(50,60,70,80,90,100 keV)and reconstructed images,which were measured at the internal carotid bifurcation.CT value and noise value(N),and calculate the corresponding signal-to-noise ratio(SNR),contrast-to-noise ratio(CNR),subjective scoring of the two groups of image quality by 5-point method,and statistical comparison of the above values.120 patients with head and neck CTA were randomly divided into group A and group B,60 cases in each group: group A used CT scan and CTA examination with 80-140 kVp fast switching technique;group B used 120 kVp Conventional CT plain scan and CTA scan.The CT values and standard deviations of the middle cerebral artery,carotid bifurcation,aortic arch and the same layer of soft tissue were measured in the two groups,and the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated.The method performed subjective scoring on the image quality of the two groups,and the image quality score of the bone removal effect by the 4-point method,and recorded the CT dose volume index(CTDIvol)and the dose length product(DLP)in the two groups,and calculated the effective radiation.Dose(ED),a statistical comparison of the values between the two groups.Result:The single-energy image at 60 keV has the highest signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR),and as the energy increases,the noise value(N)of the image decreases.There was no difference in the general data between group A and group B.There was no difference in CT value.The differences of SNR,CNR,CTDIvol,DLP and ED between the two groups were statistically significant(p<0.05).The bone removal effect score of group A was statistically significant.Compared with group B(p <0.05),the radiation dose of group A(mean 5.62mSv)was 30.19% lower than that of group B(8.05mSv)(p<0.05),and the total iodine intake of group A was 14 g,which was significantly lower than that.Group B(17.5 g).In conclusion:The 60 keV single energy image of the head and neck energy spectrum CTA has the highest SNR and CNR,which is the best single energy image.Head and neck energy spectrum CTA has the advantage of improving image quality and reducing radiation dose and iodine intake compared to conventional mixed energy CTA.