降低对比剂浓度对心肌双能量成像图像质量的研究

发布时间：2018-05-17 15:38

本文选题：心肌 + 双源CT　；参考：《新疆医科大学》2017年硕士论文

【摘要】：目的:分析与探讨在双源CT((Dual—Source CT)双能量冠状动脉CT成像(Coronary CT Angiography,CCTA)中,降低对比剂浓度注射方案在心肌成像中的应用效果。方法:连续收集临床疑诊为冠心病且行双源CT双能量扫描的患者60例,采用随机数字表法随机分为A、B两组,每组30例。A组采用含碘量为370mg/ml对比剂、B组采用含碘量为320mg/ml对比剂均行双源CT双能量扫描。均以5.5ml/s的流率注射对比剂80ml,两组患者其余参数一致。将扫描得到的原始图像采用常规重组技术,重组出A、B两组常规混合能量图像(即A1、B1);并以5kev为间距,重建出A、B两组的单能量图像(60、65、70、75、80、85、90kev),即A2~A8组、B2~B8组。分别测量A1~A8组、B1~B8组横轴位四腔心平面,左心室外侧壁及前胸壁脂肪的CT值、噪声值,计算出两组左室外侧壁的信噪比(Signal Noise Ratio,SNR)、对比噪声比(Contrast Noise Ratio,CNR),A组与B组采用单因素方差分析客观评价指标,组内两两比较采用LSD法,得出最佳kev。采用独立样本t检验比较A组混合能量(即A1)与B组最佳kev(即B5)、A组最佳kev(即A5)与B组最佳kev(即B5)之间的差异。结果:使用常规对比剂浓度(含碘370mg/ml)单能量心肌成像时,A2~A8组左室侧壁的SNR均较A1组混合能量(3.2±1.5)升高且差异均有统计学意义(P0.01),噪声(SD)较A1组混合能量(44.4±11.9)减低且差异均有统计学意义(P0.01),A2~A8组行组内两两比较,均无统计学意义(P值均0.05);其中A5组CNR(8.2±2.3)、SNR(4.8±1.7)值较A1组CNR(5.7±2.5)、SNR(3.16±1.51)增高(P值均0.01),且SD(19.2±2.6)较A组减低(P0.01)有统计学意义,即75keV为最佳keV。使用低浓度对比剂(含碘320mg/ml)单能量心肌成像时,B2~B8组左室侧壁的SNR均较B1组混合能量(3.1±1.5)升高且差异均有统计学意义(P0.01),噪声(SD)较B1组混合能量(45.0±12.0)减低且差异均有统计学意义(P0.01),B2~B8组行组内两两比较,均无统计学意义(P值均0.05);其中B5组为最佳单能量Kev水平,即75keV。B5组(320mg/ml对比剂行单能量扫描75 keV)左心室侧壁图像噪声(22.3±7.2)较与A1(44.4±11.9)混合能量图像减低,且有统计学差异(P值0.05);另B5组左心室侧壁图像噪声(22.3±7.2)信噪比(4.1±1.2)、对比噪声比(8.2±3.3)与A5组比较差异均无统计学意义(P值均0.05)。结论:降低对比剂浓度含碘320mg/ml结合最佳单能量75kev水平行双源CT双能量心肌成像时,可获得与常规对比剂含碘370mg/ml混合能量相当的客观图像质量,并仍能满足临床诊断的需求。
[Abstract]:Objective: to analyze and evaluate the effect of contrast agent injection in coronary CT angiography in dual-source CT((Dual-Source. Methods: sixty patients with suspected coronary heart disease and double source CT double energy scanning were collected and randomly divided into two groups by random digital table. Each group (n = 30) received dual source CT dual energy scan with iodine content as 370mg/ml contrast agent and B group with iodine content as 320mg/ml contrast medium. The flow rate of 5.5ml/s was injected with 80 ml contrast agent, and the other parameters of the two groups were the same. The original images were reconstructed by conventional recombination technique, two groups of conventional mixed energy images (A1B) were reconstructed, and the single energy images of two groups of AHB were reconstructed by using 5kev as the interval. The single energy images of the two groups were reconstructed, namely, B2B8 group of A2~A8 group, which was called group B2B8 of A2~A8 group, which was composed of two groups of single energy images, namely, group B2B8 of A2~A8 group, which was divided into two groups: group B2B8, group B2B8 and group B2B8. The CT value and noise value of fat in lateral wall of left ventricle and anterior chest wall in A1~A8 group were measured respectively. The signal-to-noise ratio (signal-to-noise ratio) of left ventricular lateral wall was calculated and compared with that of group A and group B by univariate ANOVA objective evaluation. The best Kevs were obtained by using LSD method. The difference between the mixed energy (A1) of group A and the best KevA (A5) of group B was compared with that of group B (A5) by t test of independent samples. Results: the SNR of left ventricular lateral wall in group A _ (2) A _ (8) was significantly higher than that in group A _ (1) (3. 2 卤1. 5) when the concentration of conventional contrast medium (containing iodine 370 mg / ml) was 370 mg 路ml ~ (-1), and the difference was statistically significant (P < 0. 01), and the difference was lower than that in group 1 (4. 4 卤11. 9). There were significant differences between two groups in P0.01A2A8 group. There was no significant difference in P value between A5 group and A1 group (P = 0.01g, SD(19.2 卤2.6). 75keV was the best Kev in A5 group (P < 0.05), which was significantly higher than that in A 1 group (P < 0.05 卤2.30 卤1.51), and SD(19.2 卤2.6 was lower than that in A group (P < 0.01), which indicated that 75keV was the best Kev in A5 group (P < 0.05), which was higher than that in A 1 group (P < 0.05), and SD(19.2 卤2.6) was significantly lower than that in A group (P 0.01). The SNR of left ventricular lateral wall in B2OB8 group was significantly higher than that in B1 group (3.1 卤1.5), and the difference was statistically significant (P 0.01), noise SDD was lower than that of B1 group (45.0 卤12.0), and the difference was statistically significant. The clinical significance of P0.01B2OB8 group was compared in two groups. There was no statistical significance (P = 0.05), among which the best single energy Kev level was found in B5 group, that is, the noise of left ventricular lateral wall image was 22.3 卤7.2 in 75keV.B5 group and decreased in 75keV.B5 group with 320mg / ml contrast medium (P < 0.05 卤7.2g / ml) compared with 44.4 卤11.9% mixed energy image with A _ 1N _ (44.4 卤11.9). There were significant differences in P value (P = 0.05) and in left ventricular lateral wall image (n = 22.3 卤7.2), signal-to-noise ratio (S / N = 4.1 卤1.2), contrast noise ratio (n = 8.2 卤3.3) and group A (n = 0.05) in B5 group. Conclusion: when dual source CT dual energy myocardial imaging is performed by decreasing the concentration of iodine 320mg/ml and the best single energy 75kev level, the objective image quality comparable to the mixed energy of conventional contrast medium with iodine 370mg/ml can be obtained, and it can still meet the needs of clinical diagnosis.
【学位授予单位】：新疆医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R541.4;R816.2

【相似文献】