Preliminary study of dual-source CT monochromatic energy imaging on the detection of hepatocellular carcinomas / 实用放射学杂志

ABSTRACT

Objective To explore the best keV conditions of show hepatocellular carcinoma lesions with the best contrast-to-noise ratio (CNR)and image quality,and evaluate the effect of monochromatic energy imaging on the detection of hepatocellular carcinomas.Methods The dual-energy CT imaging of 30 patients with hepatocellular carcinoma were analyzed retrospectively.Monochromatic energy images (40 to 140 keV,interval 10 keV)were produced by the dual-engery software.CNR and image noise of monochromatic energy,100 keV and 140 keV images were measured respectively.The CNR and the imaging noise were optimized.The results between the monochromatic energy images and the mixed energy images were compared by using the two related samples of non-parameter rank test.Results In the arterial phase, the monochromatic energy level with the highest CNR was concentrated at 70 keV,and the lowest level of the image noises was at 70 and 80 keV.The images at 70 keV were chosen to be compared with the fusion images.The CNR values of the monochromatic images at 70 keV were similar as those at 100 keV (1 .68 ± 1 .04 vs 1 .88 ± 1 .59 ,P =0 .149 ),and significantly higher than those at 140 keV (1 .68 ± 1 .04 vs 0.62±0.92,P =0.000).The image noises at 70 keV were similar as those at 140 keV (6.52±1.53 vs 7.60±2.73,P =0.050), and significantly lower than those at 100 keV (6.52±1.53 vs 8.55±1.11,P =0.000).Conclusion The monochromatic energy imaging at 70 keV can improve the CNR of the hepatocellular carcinoma lesions without reducing the image quality,which will help the lesion detection.