iDose~4迭代重建在双低剂量头颈CTA的模型应用及临床研究

发布时间：2018-04-18 02:40

本文选题：低管电压 + 低剂量　；参考：《重庆医科大学》2017年硕士论文

【摘要】：目的:探讨iDose~4迭代重建重建级别的选择及高级别iDose~4迭代重建在双低剂量头颈部CT血管成像(CTA)的应用可行性,并评价iDose~4迭代重建在正常体质量指数(BMI)患者头颈部CTA降低辐射剂量、碘摄入量及控制影像图像质量的临床应用价值。方法:模型研究:建立8种不同浓度血管模型,应用Philips Brilliancei 256排CT扫描仪在管电压100 k V、管电流250 m As条件下对血管模型进行扫描,并采用iDose~4 3-5级对图像进行重建,评价图像质量。采用不同管电压(100、120 k V)和管电流(200、250、300、350 m As)对血管模型进行两两组合扫描,图像进行iDose~4-5重建,记录血管模型CT值,分析CT值与浓度的关系。临床研究:将52例拟行头颈CTA检查BMI正常患者随机分为双低组和常规组,双低组患者采用100 k V扫描,iDose~4-5进行重建,对比剂使用40 ml碘克沙醇(270 mg I/ml)。常规组患者采用120 k V扫描,滤波反投影(FBP)进行重建,对比剂使用50 ml碘帕醇(370 mg I/ml)。对两组患者一般情况、图像质量、辐射剂量及平均碘摄入量进行统计学分析。结果:模型研究:低管电压扫描(100 k V,250 m As)iDose~4-3,iDose~4-4,iDose~4-5三种重建级别图像CNR无统计学差异(P0.05)。但iDose~4-5重建图像SNR明显优于iDose~4-3重建,差异有统计学意义(P0.05)。碘浓度与血管模型CT值呈正相关(100 k V:r=0.997,P0.01;120 k V:r=0.993,P0.01)。临床研究:两组患者年龄、体重、身高、BMI差异均无统计学意义(P均0.05)。双低组颈总动脉、颈内动脉、椎动脉CT值均低于常规组(P均0.05)。两组主观评分、SNR、CNR差异均无统计学意义(P均0.05)。双低组双侧颈静脉污染评分均高于常规组(P均0.05)。双低组辐射剂量和平均碘摄入量均低于常规组(P均0.05)。结论:高级别的迭代重建能获得更优质的图像。低管电压能提高目标血管CT值。对于正常BMI患者,高级别迭代重建在双低剂量头颈部CTA中能得到高质量的影像图像,并使辐射剂量和平均碘摄入量明显降低。
[Abstract]:Objective: to investigate the selection of iDose~4 iterative reconstruction grade and the feasibility of high grade iDose~4 iterative reconstruction in double low dose CT angiography of head and neck, and to evaluate the reduction of radiation dose of iDose~4 iterative reconstruction in head and neck of patients with normal body mass index (NMI).Clinical application value of iodine intake and image quality control.Methods: eight vascular models with different concentrations were established. The vascular models were scanned by Philips Brilliancei 256 CT scanner under the condition of voltage 100kV and current 250mAs, and the images were reconstructed by iDose~4 3-5 stage.Evaluate image quality.The vascular model was scanned with different tube voltage (100120kV) and tube current (200250300350mAs). The images were reconstructed by iDose~4-5. The CT value of vascular model was recorded and the relationship between CT value and concentration was analyzed.Clinical study: 52 normal patients with head and neck CTA were randomly divided into double low group and routine group. The patients in double low group were reconstructed by 100kV scanning iDose4-5, and 40 ml iodoxacin 270mg / ml was used as contrast agent.The patients in the routine group were reconstructed with 120 kV scan and filtered backprojection (FBP), and 50 ml iodipine 370 mg I / ml was used as contrast agent.The general condition, image quality, radiation dose and average iodine intake of the two groups were analyzed statistically.Results: the model study showed that there was no significant difference in CNR among the three kinds of reconstruction grade images (P0.05).But the SNR of iDose~4-5 was better than that of iDose~4-3, and the difference was statistically significant (P 0.05).There was a positive correlation between iodine concentration and CT value of the vascular model. There was a positive correlation between the concentration of iodine and the CT value of the vascular model. There was a positive correlation between the concentration of iodine and the CT value of the vascular model.Clinical study: there was no significant difference in age, weight, height and BMI between the two groups (P < 0.05).The CT values of common carotid artery, internal carotid artery and vertebral artery in double low group were lower than those in routine group (P < 0.05).There was no significant difference in CNR between the two groups (P < 0.05).The scores of bilateral jugular venous pollution in the double low group were higher than those in the routine group (P < 0.05).The radiation dose and average iodine intake in the double low group were lower than those in the routine group (P < 0.05).Conclusion: high-level iterative reconstruction can obtain better image.Low tube voltage can improve the CT value of the target blood vessel.For normal BMI patients, high level iterative reconstruction in dual low dose head and neck CTA can obtain high quality image, and reduce the radiation dose and average iodine intake significantly.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R816.2

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