能谱CT最佳单能量成像优化肝脏血管图像质量的研究

摘要

Objective:To investigate the value of the optimal monochromatic imaging with spectral CT for the improvement of image quality of liver vessels.Methods:The abdominal spectral CT imaging and clinical materials of 35 patients with abdominal disease were analyzed retrospectively.Liver vessels including common hepatic artery (CHA),portal vein (PV) and hepatic vein (HV) were reconstructed by 140kVp mixed energy (quality check,QC),70keV and optimal monochromatic mode,respectively.Parameters including CT value,image noise (IN),contrast-to-noise ratio (CNR),signal-to-noise ratio (SNR) and subjective image score of CHA,PV and HV were compared and analyzed statistically.Results:The CNR of CHA of the optimal monochromatic mode group,70keV group and QC group was 24.55±10.86,18.12±8.32 and 11.64±4.64,respectively,the subjective image score was 4.74±0.16,4.04±0.30 and 3.62±0.35,respectively.The CNR of PV was 6.94 ± 2.73,4.26 ± 1.90 and 2.97± 2.11,respectively,the subjective image score was 4.45 ± 0.30,3.87 ± 0.37 and 3.30± 0.34,respectively.The CNR of HV was 5.74 ± 2.28,4.24 ± 1.92 and 2.72 ± 1.44,respectively,the subjective image score was 4.31 ± 0.33,3.75 ± 0.41 and 3.24 ± 0.34,respectively.All showed significant statistic difference (P＜ 0.01 for all).Statistic difference was also shown between two-two groups comparison (P＜0.05 for all).The CNR,SNR and subjective image score of the optimal monochromatic mode group were superior to those of the 70keV group and QC group.Conclusion:The CNR and SNR of common hepatic artery,hepatic portal vein and hepatic vein could be enhanced by using optimal monochromatic imaging,therefore the image quality of hepatic vessels could be improved.%目的:探讨能谱CT单能量成像对优化肝脏血管图像质量的价值.方法:回顾性分析行腹部能谱CT检查的35例腹部疾病患者的病例资料,应用能谱分析软件,分别采用140 kVp混合能量模式(QC)、70 keV单能量、最佳单能量模式进行肝总动脉、门静脉及肝静脉重建,比较QC、70 keV和最佳单能量3组图像肝总动脉、门静脉及肝静脉的CT值、图像平均噪声值(IN)、对比噪声比(CNR)、信噪比(SNR)及图像质量主观评分,并进行统计学分析.结果:最佳单能量组、70 keV组、QC组肝总动脉的CNR分别为(24.55±10.86)、(18.12±8.32)和(11.64±4.64),图像质量评分分别为(4.74±0.16)、(4.04±0.30)和(3.62±0.35)分;门静脉CNR分别为(6.94±2.73)、(4.26±1.90)和(2.97土2.11),图像质量评分分别为(4.45±0.30)、(3.87±0.37)和(3.30±0.34)分;肝静脉CNR分别为(5.74±2.28)、(4.24±1.92)和(2.72±1.44),图像质量评分分别为(4.31±0.33)、(3.75±0.41)和(3.24±0.34)分,差异均有统计学意义(P值均＜0.01),组间两两比较差异也均有统计学意义(P值均＜0.05),最佳单能量组肝脏血管的CNR、SNR和图像质量主观评分均优于70 keV单能量组和QC组.结论:能谱CT最佳单能量成像能够提高肝脏动脉、门静脉及肝静脉的CNR和SNR,从而优化肝脏血管图像质量.