能谱CT最佳单能量成像可改善肾静脉成像质量

Spectral CT with optimal monochromatic images can improve the quality of renal venography

目的探讨能谱CT最佳单能量在低剂量肾静脉成像中的应用价值。方法收集2022年5月~2023年10月陕西中医药大学附属医院能谱CT肾静脉成像患者40例并随机分为A、B两组,20例/组。A组采用常规120 kVp管电压,对比剂浓度600 mgI/kg,采用40%自适应统计迭代重建技术(ASIR)重建;B组采用宝石能谱成像模式扫描,对比剂浓度450 mgI/kg,采用40%ASIR重建最佳单能量图像。分别测量左肾静脉、右肾静脉及同层面左侧竖脊肌的CT值及SD值,并计算左、右肾静脉的信噪比和对比噪声比值。由2位有经验的影像科医师采用五分法对肾静脉图像进行双盲法主观评分。记录两组患者CT容积剂量指数和剂量长度乘积,计算有效辐射剂量。结果两组患者基本资料的差异无统计学意义(P>0.05)。B组患者对比剂碘摄入量、有效辐射剂量较A组分别减少26.2%和23.5%,差异有统计学意义(P<0.05)。B组图像肾静脉CT值、信噪比和对比噪声比值均高于A组(P<0.05),SD值低于A组(P<0.05)。B组图像主观评分高于A组,差异有统计学意义(P<0.05)。结论能谱CT最佳单能量可以显著降低肾静脉成像的对比剂碘摄入量和有效辐射剂量,并可获得优于常规120 kVp扫描的肾静脉图像。

Objective To explore the application of optimal monochromatic images using dual-energy spectral CT in low-dose renal venography.Methods Forty patients for renal CT venography in Affiliated Hospital of Shaanxi University of Chinese Medicine from May 2022 to October 2023 were recruited and randomly divided into group A and group B,with twenty patients each.Group A was scanned with conventional 120 kVp with contrast agent dose of 600 mgI/kg and reconstructed with 40%ASIR.Group B was scanned with dual-energy spectral CT mode with contrast agent dose of 450 mgI/kg and reconstructed with 40%ASIR and the optimal monochromatic images.The CT values and standard deviation of the left renal vein,right renal vein and erector muscle at the same level were measured to calculate the signal-to-noise-ratio and contrast-to-noise ratio values for the renal veins.The image quality was subjectively scored by two experienced radiologists blindly using a 5-point system.The CT volumetric dose index and dose length product were recorded for both groups and the effective radiation dose was calculated.Results There were no significant difference in general data between the two groups(P>0.05).The contrast agent dose and effective radiation dose in group B were decreased by 26.2%and 23.5%respectively compared with group A(P<0.05).The CT values,signal-to-noise-ratio values and contrast-to-noise ratio values of group B were significantly higher than those of group A(P<0.05),and the standard deviation values was significantly lower than that of group A(P<0.05).The subjective score of group B was significantly higher than that of group A and the differences showed significant differences(P<0.05).Conclusion Spectral CT imaging with optimal monochromatic images can significantly reduce contrast agent dose and radiation dose in renal venography,and provide better image quality than the conventional 120 kVp protocol.