能谱CT最佳单能量肠系膜上动脉成像的价值

目的 探讨能谱CT最佳单能量技术在肠系膜上动脉成像中降低对比剂用量和提升图像质量的可行性.方法 收集我院肠系膜上动脉CTA受检者40例并随机分为A、B两组,A组采用能谱CT成像模式,对比剂用量450 mg I/kg,扫描后重组最佳单能量、40％ASIR图像;B组行常规120 kVp增强扫描,对比剂用量600 mg I/...

Reducing contrast medium dose in superior mesenteric artery imaging with optimal monochromatic energy of dual-energy spectral CT mode

Objective To investigate the possibility of reducing contrast medium(CM)dose and improving image quality in superior mesenteric artery(SMA)imaging with optimal monochromatic energy of dual-energy spectral CT mode.Methods Forty patients undergoing contrast-enhanced abdominal CT were randomly divided into 2 groups.Patients in group A were scanned with spectral CT imaging mode,450 mg I/kg of CM,optimal monochromatic energy,and 40%ASIR reconstruction.Patients in group B underwent conventional CT at 120 kVp with 600 mg I/kg of CM,and 40%ASIR reconstruction.The CT densities and standard deviation(SD)values of SMA and erector muscle at the same level were measured,and the signal to noise ratio(SNR)as well as contrast to noise ratio(CNR)were calculated.The image quality was scored independently by two experienced radiologists using volume rendering,maximum intensity projection,multi-planar reconstruction and curved-planar reconstruction.The CM iodine intake,volume CT dose index(CTDIvol)and dose length product(DLP)were recorded and effective radiation dose(ED)was calculated.The independent sample t test and Mann-Whitney U test were used for statistical analysis.Results The general data,CTDIvol,DLP,ED between the two groups showed no significant difference(P>0.05).The CM iodine intake in group A[(25.47±3.43)g]was significantly(P<0.05)reduced by 26.6%compared with that in group B[(35.80±6.18)g].The CT densities,SNR,and CNR of SMA in group A were significantly higher than those in group B(P<0.05),whereas the SD values in group A were slightly lower than that in group B(P>0.05).The image quality scores of two radiologists showed good consistency(κ>0.80,P<0.05)with significantly(P<0.05)higher scores in group A(4.65±0.59)than that in group B(3.86±0.57).Conclusion At similar radiation dosage,the optimal monochromatic energy of dual-energy spectral CT mode can significantly reduce the CM iodine intake by 26.6%with better image quality than that of conventional 120 kVp enhanced CT of SMA.