| Objectives 1 To explore the effect of changing the trigger monitoring point on the image quality of pulmonary CT imaging.2 To explore the effect of accelerated saline injection flow rate on the image quality of pulmonary CT imaging.Methods A total of 240 patients who met the inclusion criteria from November 2018 to November 2019 were collected.Randomly divided into conventional group,experimental group A,experimental group B1,experimental group B2,experimental group B3,experimental group C1,experimental group C2 and experimental group C3,which were divided into eight groups.The automatic tracking trigger scan method was used,and the injection rate of each group was 4.5 ml/s.The trigger point of the conventional group was located in the superior vena cava,and the saline injection flow rate was 4.5ml/s.The triggering monitoring point of the experimental group A,experimental group B1,experimental group B2 and experimental group B3 was located in the right atrium.The injection flow rate of the normal saline in the experimental group A is 4.5 ml/s.The normal saline injection flow rate was 5.0ml/s in experimental group B1.The normal saline injection flow rate was 5.5ml/s in experimental group B2.The normal saline injection flow rate was 6.0ml/s in experimental group B3.The trigger monitoring points of the experimental C1 group,the experimental C2 group and the experimental C3 group were located in the superior vena cava.The normal saline injection flow rate was 5.0ml/s in experimental group C1.The normal saline injection flow rate was 5.5ml/s in experimental group C2.The normal saline injection flow rate was 6.0ml/s in experimental group C3.Other scanning technical parameters were the same.The CT value of pulmonary artery trunk,CT value of superior vena cava,CT value of right inferior pulmonary vein,CT value of grade 6 pulmonary artery,superior vena cava artifact score and image quality score of enhanced pulmonary artery were recorded and statistically analyzed in all groups.Results All 240 cases were scanned successfully.The general information of each group was compared,the test results showed that the differences were not statistically significant.The average quality scores of the superior vena cava artifacts in the conventional group and the experimental group A were 3.13±0.35 and 4.97±0.18,the differences between the two groups were statistically significant.The average scores of the superior vena cava artifact image quality of the conventional group,experimental C1 group,experimental C2 group,and experimental C3 group were 3.13±0.35,3.13±0.35,4.90±0.31,4.93±0.25.The difference between the four groups was statistically significant.Comparison between the two groups showed that the difference between the conventional group and the experimental group C1 was not statistically significant,and the differences between the other groups were statistically significant.The CT values of the pulmonary artery trunk in the experimental group B1,the experimental group B2,and the experimental group B3 were 368.99±21.70 HU,380.87±21.91 HU and 409.07±19.18 HU.The CT values of the three groups were compared,and the difference was statistically significant.The difference between the groups was statistically significant.The CT values of the pulmonary artery trunk in the experimental group C1,the experimental group C2,and the experimental group C3 were 348.53±17.81 HU,375.33±26.83 HU,and 395.51±23.01 HU.The comparison among the three groups was statistically significant.The significance of the study was further compared,the difference was statistically significant.There was a significant difference in the CT value of the pulmonary arteries between the experimental group B1 and the experimental group C1.There was no significant difference in the CT value of the pulmonary arteries between the experimental group B2 and the experimental group C2.There was a difference in the CT values of the pulmonary arteries between the experimental group B3 and the experimental group C3.The CT values of superior vena cava in experimental group B1,experimental B2 group,and experimental B3 group were 115.36±16.92 HU,110.87±24.05 HU,113.73±13.32 HU.The CT values of superior vena cava in experimental group C1,experimental C2 and experimental C3 were 1056.56±141.27 HU,904.63±39.08 HU,797.73±55.91 HU.There was significant difference in the CT value of superior vena cava between the experimental group B1 and the experimental group C1,there was significant difference in the CT value of superior vena cava between the experimental group B2 and the experimental group C2,there was significant difference in the CT value of superior vena cava between the experimental group B3 and the experimental group C3.The CT values of the lower right pulmonary vein in the experimental group B1,the experimental B2 group and the experimental B3 group were 161.26±36.00 HU,172.5±27.84 HU,154.13±42.19 HU.The CT values of the lower right pulmonary vein in the experimental group C1,experimental C2 and experimental C3 were 163.62±36.07 HU,163.65±34.26 HU,161.02±36.12 HU.There was no significant difference in CT value ??of the right lower pulmonary vein between the experimental group B1 and the experimental group C1.There was no difference in the CT value of the right lower pulmonary vein between the experimental group B2 and the experimental group C2.There was no significant difference in CT value of right lower pulmonary vein between experimental group B3 and experimental group C3.The display rates of the six-stage pulmonary arteries the experimental B1,the experimental B2 and the experimental B3 were 80.00%,83.33%,and 86.67% and the experiment grade 6 pulmonary arteries in experimental C1,experimental C2 and experimental C3 were 86.67%,90.00%,90.00%,there is no significant difference in the display rate of grade 6 pulmonary arteries between the experimental B1 group and the experimental C1 group,there is no significant difference in the display rate of the grade 6 pulmonary arteries of the experimental B2 group and the experimental C2 group,there is no significant difference between the experimental B3 group and the experimental C3 group.The average scores of the pulmonary artery image quality of the experimental group B1,the experimental B2 group,and the experimental B3 group were 4.93±0.25,4.90±0.31,4.97±0.18 and the average pulmonary artery image quality scores of the experimental C1 group,the experimental C2 group,and the experimental C3 group were 4.90±0.31,4.87±0.35,4.93±0.25.There was no significant difference in the average scores of the pulmonary artery image quality between the experimental group B1 and the experimental group C1.There was no significant difference in the average scores of the pulmonary artery image quality between the experimental group B2 and the experimental group C2.There was no significant difference in the average score of pulmonary artery image quality between the experimental group B3 and the experimental group C3.The average image quality scores of superior vena cava artifacts in experimental group B1,experimental B2 and experimental B3 were 4.93±0.25,4.97±0.18,and 4.90±0.31.The average image quality scores of superior vena cava artifacts in experimental C1,experimental C2 and experimental C3 were 3.13±0.35,4.90±0.31,4.93±0.25.There was no significant difference in the image quality scores of the superior vena cava artifacts between the experimental group B1 and experimental group C1,there was no significant difference in the image quality scores of the superior vena cava artifacts between the experimental group B2 and experimental group C2,there was a statistically significant difference in the quality scores of the superior vena cava artifacts in the experimental group B3 and the experimental group C3.Conclusion 1 Changing the trigger monitoring point can eliminate the radial artifacts caused by the high concentration of contrast agent in the superior vena cava,and avoid the diaphragmatic breathing motion artifacts,the image quality can meet the requirements of clinical diagnosis.2 Do not change the trigger monitoring point,speed up the saline injection flow rate,Under the condition of a large saline injection flow rate,not only can the high vena cava contrast agent artifact be avoided,but also the pulmonary artery can be enhanced,the image quality can meet the requirements of clinical diagnosis.3 In the pulmonary artery imaging,the right atrium is a triggering monitoring point and at the same time the saline injection flow rate is combined to improve the image quality better than a single solution.Figure 4;Table 9;Reference 66... |
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