低浓度对比剂单能量成像对提高肝静脉成像质量的研究

发布时间：2018-03-13 03:37

本文选题：肝静脉　切入点：体层摄影术　出处：《中国临床医学影像杂志》2015年02期 　论文类型：期刊论文

【摘要】：目的:探讨低浓度对比剂双能量CT最佳单能量成像对提高肝静脉成像质量的应用价值。方法:前瞻性研究151例行双能量CT全腹增强扫描的且体质量指数(BMI)25 kg/m2的患者,按照首诊时间将患者随机分为低浓度对比剂能谱扫描单能量成像组(A组,管电压140 k Vp和80 k Vp瞬时切换,对比剂浓度为270 mg I/m L)和高浓度对比剂常规扫描组(B组,管电压120 k Vp,对比剂浓度为350 mg I/m L),将A组静脉期薄层图像应用最佳对比噪声比(Optimal CNR)技术获得最佳单能量图像。对A组最佳单能量图像和B组图像分别进行肝静脉重建(MIP,VR),分别测量两组图像肝左、中、右静脉和肝实质的CT值、肝实质的背景噪声(SD值),计算肝左、中、右静脉的CNR,对两组图像的肝静脉CNR进行独立样本t检验;由2名观察者盲法对两组图像肝静脉显示情况进行主观质量评分,采用Kappa检验评价两观察者评估一致性,并以Mann-Whitney U检验比较两组肝静脉评分差异。记录两组病例的CTDIvol,以独立样本t检验进行比较;计算并比较两组对比剂总碘量。结果:A组肝静脉最佳单能图像能量水平集中在49~51 ke V。两组肝左静脉、肝中静脉、肝右静脉、肝实质的CT值分别为(335.29±68.45)HU、(343.16±73.95)HU、(327.80±76.22)HU、(187.74±31.98)HU,(194.82±33.60)HU、(196.62±36.11)HU、(190.60±33.61)HU、(115.89±16.94)HU;肝左、中、右静脉与肝实质的CT值差值、肝实质的背景噪声值分别为(147.39±48.91)HU、(155.26±56.68)HU、(139.90±55.19)HU、(39.12±10.04)HU,(78.93±27.92)HU、(80.73±28.44)HU、(74.71±26.03)HU、(33.82±8.94)HU;两组图像的肝左、中、右静脉CNR值分别为3.93±1.80、4.35±2.29、3.91±2.08,2.40±0.85、2.44±0.82、2.26±0.75,以上数据A组均明显高于B组,且差异均具有统计学意义(P值均0.05)。2名观察者对两组图像肝静脉评分的一致性良好(Kappa值均0.80),两组肝静脉评分为(3.43±0.58)分和(3.48±0.68)分,差异无统计学意义(P=0.683)。A、B两组CTDIvol分别为(16.87±0.00)m Gy和(15.74±5.26)m Gy,二者无统计学差异(P0.05);A组和B组的总碘量分别为27 000 mg和35 000 mg,A组较B组降低22.86%。结论:对BMI25 kg/m2者,通过双能量CT最佳CNR技术,应用低浓度浓度对比剂在降低总碘含量的同时,可以获得更高质量的肝静脉图像,且不增加辐射剂量。
[Abstract]:Objective: to evaluate the value of low concentration contrast medium double energy CT single energy CT in improving the quality of hepatic vein imaging. The patients were randomly divided into two groups according to the time of first diagnosis: group A with low concentration of contrast agent and single energy imaging group with low concentration of contrast agent. The tube voltage of 140 kV p and 80 kV P was switched instantly, the concentration of contrast agent was 270 mg I / m L) and the group B of routine scanning with high concentration contrast agent was divided into two groups. The tube voltage was 120 kV / p and the concentration of contrast agent was 350 mg I / mL. The best single energy image was obtained by using the best contrast noise ratio (optimal CNR) technique in the thin layer image of group A. the optimal single energy image of group A and the image of group B were treated with liver static, respectively. The left liver of two groups of images were measured. Ct value of middle, right vein and hepatic parenchyma, background noise of hepatic parenchyma and SD value were calculated. The CNR of hepatic vein of left, middle and right hepatic veins were examined by independent t-test. The subjective quality of the two groups of images was evaluated by blind method of two observers, and the consistency of the two observers was evaluated by Kappa test. Mann-Whitney U test was used to compare the difference of hepatic vein score between the two groups. CTDIvoll of the two groups were recorded and compared with independent sample t-test. Results the optimal monoenergetic image energy level of hepatic vein in group A was 4951 Kev. The CT values of left hepatic vein, middle hepatic vein, right hepatic vein and hepatic parenchyma were 335.29 卤68.45hus 343.16 卤73.95 HUU 327.80 卤76.227.74 卤31.98 HUU 194.82 卤36.111.115.89 卤16.94HUU, respectively. The difference of CT value between right vein and hepatic parenchyma and the background noise of hepatic parenchyma were 147.39 卤48.91HUA 155.26 卤56.68HU 139.90 卤55.19HUA 39.12 卤10.04HUA 78.93 卤27.92HUU 70.73 卤28.444.71 卤26.03HUHU33.82 卤8.94HUU, the CNR values of left and middle hepatic veins in both groups were 3.93 卤1.804.35 卤2.293.91 卤2.084.35 卤2.2983.91 卤0.882.44 卤0.822.26 卤0.75, respectively, which were significantly higher than those in group B, and the CNR values of left and middle hepatic veins in both groups were 3.93 卤1.804.35 卤2.293.91 卤2.082.40 卤0.852.44 卤0.822.26 卤0.75, respectively. The difference was statistically significant (P < 0.05). The consistency of hepatic vein score between the two groups was good. The Kappa score of the two groups was 0.80, the hepatic vein score of the two groups was 3.43 卤0.58 and 3.48 卤0.68, respectively. There was no significant difference in CTDIvol between group A and group B (16.87 卤0.00m Gy and 15.74 卤5.26 mGy, respectively). There was no significant difference between group A and group B. the total iodine content of group A and group B were 27000 mg and 35000 mg / g respectively lower than that of group B.Conclusion: for BMI25 kg/m2, double energy CT is the best CNR technique. The application of low concentration contrast agent can reduce the total iodine content at the same time obtain higher quality of hepatic vein image without increasing the radiation dose.
【作者单位】：大连医科大学附属第一医院放射科;
【分类号】：R575;R816.5

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