Clinical Value Of GSI Monochromatic Imaging Plus Multi-Parameter In Carotid Atherosclerotic Plaque

Objective To explore the clinical value of GSI monochromatic energy imaging plus multi-parameter in evaluating carotid atherosclerotic plaque.Methods A total of one hundred patients(58 males and 42 females)who underwent carotid CTA of GSI were enrolled in this study.At the very beginning,10 monochromatic images from40 to 140 ke V(in 10-ke V increments)were reconstructed with six ASi R percentages: 0%,20%,40%,60%,80%,and 100%.First,In the 66 sets of monochromatic images,the imaging quality(both subjective and objective evalution)were assessed to select the optimal monochromatic imaging parameter combination.Second,the CNR,noise and the percentage of each components in plaque were compared between optimal monochromatic energy imaging and polychromatic imaging.Third,use GSI multi-parameter(energy spectrum curve and Effective-Z,etc.)to jointly verify the accuracy of the cutoff value of lipids and fiber tissue in carotid atherosclerotic plaque,then using the optimal monochromatic imaging,the cutoff value between fiber and lipids tissue was corrected.Comparing the percentages of the lipids and fiber tissue in plaques with cutoff value corrected before and after using the optimal monochromatic imaging.P<0.05 meant the difference was statistically significant.Results First,The optimal SNR and CNR for carotid CTA was achieved at 60 ke V.The imag e noise decreased with the increase of ke V and ASi R,the most significant liner decrease trend was in 40-60 ke V.In 66 monochromatic images sets,the optimal image quality was obtained in the 60 ke V + 60% ASi R.Second,compared with polychromatic imaging,the CNR has increased by 156%,and the noise has decreased by 135% in the optimal monochromatic e nergy image.The percentage of lipids and fiber tissue in plaque between optimal monochro matic imaging and polychromatic imaging were significantly different(P<0.005).Third,the percentages of the lipids and fiber tissue in plaques before and after cutoff value correction also had significant differences(P<0.005).Conclusion First,the optimal monochromatic imaging parameter for GSI Carotid CTA was 60 ke V and 60% ASi R.Second,compared with the polychromatic imaging,the optimal monochromatic imaging had a higher imaging quality,and shown the details of plaques more clearly.Third,the optimal monochromatic imaging plus multi-parameter of GSI could provide more accurate evidences for evaluating vulnerable plaque.