The effect of optimal contrast-to-noise ratio technique of spectral imaging on the image quality of gastric arterial CT angiography

Objective:To explore the effect of optimal contrast-to-noise ratio(Optimal CNR) technique of spectral imaging on the image quality of gastric arterial CT angiography(CTA).Methods:20 patients with clinically suspected gastric cancer underwent dual-phase enhanced gemstone spectral imaging(GSI) examination.GSI viewer was used to obtain the optimal CNR monochromatic images.Both the polychromatic(140kVp) and the monochromatic image sets were post-processed with add vessel and thin slice maximum intensity projection(TSMIP) technique.The CNR,image noise of celiac trunk were calculated respectively and the image quality after reconstruction were scored,the results were compared and analyzed.Results:The monochromatic images at(51±2)keV were found to provide the best CNR for gastric arterial CTA.Compared with those of the polychromatic images,the CNR of the celiac trunk,image noise and the scores of the image quality of the optimal CNR monochromatic images increased by 71%、41% and 40% respectively.Conclusion:The optimal CNR technique of spectral imaging can improve image quality of gastric arterial CTA.