低剂量CTA在头颈血管检查中应用的研究

发布时间：2018-08-19 15:29

【摘要】：第一部分目的：应用噪声添加软件对已有的CTA横断图像进行空间噪声的添加，模拟出不同管电流条件下的图像，比较出最适的低管电流。材料与方法：分别收集BMI25及BMI25的患者的CTA横断面图像各15例，通过图像空间添加噪声软件模分别拟出100、200、300、400、500mA5种低剂量影像，根据影像质量及病灶显示的情况进行评价，找出满足诊断需求的最适球管电流。图像质量按血管边缘的锐利度及3、4级血管的显示情况而采用1-5分的评分制，等级资料使用秩和检验进行统计分析，计数资料采用X2检验。结果：BMI25的患者的原始图像及5组模拟图像均可清晰显示非钙化斑块37枚、混合斑块23枚、血管狭窄58段（其中轻度狭窄42段、中度狭窄9段、重度狭窄7段）及动脉瘤6枚；BMI25的患者的原始图像及5组模拟图像均可清晰显示非钙化斑块22枚、混合斑块11枚、血管狭窄44段（其中轻度狭窄29段、中度狭窄11段、重度狭窄4段）、1段血管闭塞及动脉瘤4枚。不同剂量的图像质量差异有统计学意义(P0.05)。BMI25组中，常规管电流时得4分5例、5分10例，管电流为300mA时得4分5例、5分10例，两者差异无统计学意义(P0.05)，而当管电流降低至200mA时，图像质量评分5分2例，4分5例，3分5例，2分1例，常规电流与200mA组两者差异有统计学意义（P0.05)；在BMI25组中，在常规管电流（649mA）时4分3例、5分12例，管电流为200mA时4分5例、5分10例，两者差别无统计学意义，而当管电流将至100mA时，图像质量评分5分1例，4分7例，3分6例，2分1例，常规电流与100mA组两者差异有统计学意义（P0.05)。第二部分目的：验证头颈CTA低管电流的可行性。材料及方法：分别选取30例BMI25及BMI25行头颈联合CTA检查的患者，将BMI25的患者分入常规管电流（649mA）组和低电流（300mA)组，各15人；BMI25的患者分组方法同上，为常规管电流（649mA)组及低管电流（200mA)组。检查结束后记录CTDI和DLP的数值，得到原始图像后，传入工作站分别行VR重建及曲面重建，进行图像质量评价，按血管边缘的锐利程度、分支的显示及斑块的显示采用1-5分的评分制。结果：BMI25组在管电流为300mA和常规管电流时，图像质量评价分别有4分3例、5分12例，4分1例、5分12例，，两者差异无统计学意义（P0.05)；BMI25组在管电流为200mA和常规管电流时，图像质量评价分别有4分4例、5分11例，4分2例、5分13例，两者差异无统计学意义（P0.05)。BMI25组中低剂量组的CTDIvol值降低了47%，DLP降低了60%；BMI25组中低剂量组较常规剂量组的CTDIvol值降低了40%，DLP降低了73%。结论：进行头颈联合CTA检查时，BMI25的患者最适的低管电流为300mA，BMI25的患者最适的低管电流为200mA，并可以明显降低辐射剂量。
[Abstract]:The purpose of the first part is to use the noise adding software to add spatial noise to the existing CTA cross section images, to simulate the images under different current conditions, and to compare the optimal low transistor current. Materials and methods: the CTA cross-sectional images of 15 patients with BMI25 and 15 patients with BMI25 were collected respectively. The low dose images of 100200300400500mA5 were drawn up by adding noise software in the image space, and evaluated according to the image quality and the display of the lesions. Find out the optimal spherical current to meet the diagnostic requirements. According to the sharpness of the edge of the blood vessel and the display of the 3 ~ 4 grade blood vessel, the image quality was scored by 1-5 points, the rank sum test was used to analyze the grade data, and the count data was analyzed by X2 test. Results the original images and 5 simulated images of the patients with BMI25 showed 37 non-calcified plaques, 23 mixed plaques, 58 vascular stenosis segments (42 mild stenosis, 9 moderate stenosis, 7 severe stenosis) and 6 aneurysms. The original images and 5 simulated images of the patients with BMI25 could clearly show 22 non-calcified plaques, 11 mixed plaques, 44 vascular stenosis segments (29 mild stenosis, 11 moderate stenosis). 4 segments of severe stenosis) 1 segment occlusion and 4 aneurysms. In the BMI25 group, there were significant differences in image quality between the two groups (P0.05). In the BMI25 group, the conventional tube current had 4 points in 5 cases, 5 in 10 cases, 300mA in 5 cases and 5 points in 10 cases. There was no significant difference between the two groups (P0.05), but when the tube current decreased to 200mA, there was no significant difference between the two groups (P0.05). Image quality score was 5 in 2 cases, 4 in 5, 3 in 5, 2 in 1. There was significant difference between conventional current and 200mA group (P0.05), in BMI25 group, there were 4 points (3 cases) and 5 points (12 cases) in conventional tube current (649mA). There was no significant difference between the two groups when the tube current was 200mA, 5 points in 5 cases and 5 points in 10 cases. When the tube current was approaching 100mA, the image quality score was 5 in 1 case, 4 in 7 cases, 3 in 6 cases and 2 in 1 case. There was a significant difference between the conventional current and 100mA group (P0.05). The second part aims: to verify the feasibility of head and neck CTA low current. Materials and methods: 30 patients with BMI25 and BMI25 who underwent head and neck combined with CTA were divided into 649mA group and low current (300mA) group, 15 patients with BMI25 were divided into two groups. It is a conventional tube current (649mA) group and a low transistor current (200mA) group. The values of CTDI and DLP were recorded at the end of the inspection. After the original images were obtained, VR reconstruction and curved surface reconstruction were performed on the workstation respectively, and the image quality was evaluated according to the sharpness of the blood vessel edge. A 1-5 score system was used for displaying branches and plaques. Results when the tube current was 300mA and conventional current, the image quality evaluation was 4 points in 3 cases, 5 in 12 cases, 4 in 1 case, and 5 in 12 cases. There was no significant difference between the two groups (P0.05) when the tube current was 200mA and conventional tube current in the BMI25 group, there was no significant difference between the two groups (P0.05). The image quality was evaluated in 4 cases, 5 points in 11 cases, 4 points in 2 cases and 5 points in 13 cases. There was no significant difference between the two groups (P0.05) .BMI25 group reduced the CTDIvol value of low dose group by 47% and decreased by 60%. The CTDIvol value of BMI25 group was decreased by 40% compared with that of normal dose group. Conclusion: the optimal low tube current of BMI25 patients with combined head and neck CTA is 300 mAX BMI25 and the optimal low tube current is 200mA. it can significantly reduce the radiation dose.
【学位授予单位】：山西医科大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：R816

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