超低管电流三维自适应迭代剂量降低重建CT猪结肠成像质量与辐射剂量

发布时间：2018-10-09 09:13

【摘要】：目的探讨超低管电流三维自适应迭代剂量降低(AIDR3D)重建CT猪结肠成像的图像质量与辐射剂量。方法制作10段猪结肠息肉模型,每段猪结肠黏膜设有30枚直径1~15mm的结节样模拟息肉。对所有模型均采用640层CT机进行扫描,管电压120kVp,电流剂量分别为10、20、30、40、50mAs。并获得滤波反投影(FBP)和AIDR3D重建图像,不同管电流及重建方法组合10组数据:A组(10mA,FBP)、B组(10mAs,AIDR3D)、C组(20 mAs,FBP)、D组(20mAs,AIDR3D)、E组(30mAs,FBP)、F组(30mAs,AIDR3D)、G组(40mAs,FBP)、H组(40mAs,AIDR3D)、I组(50mAs,FBP)、J组(50mAs,AIDR3D)。测算图像的噪声、SNR及CNR作为定量指标,并对图像质量进行主观定性评分。以有效辐射剂量为指标比较各组图像的辐射剂量。结果相同管电流条件下,AIDR3D图像的噪声低于FBP图像,SNC及CNR均高于FBP图像(P均0.05)。D组与I组图像的噪声(P=0.052)、SNR(P=0.129)及CNR(P=0.053)差异均无统计学意义。B组图像的噪声(P=0.002)高于I组,SNR及CNR均低于I组(P均0.001)。相同管电流条件下,AIDR3D图像的质量评分高于FBP图像(P均0.05)。D组与I组的图像质量评分差异无统计学意义(P=0.121)。B组的图像质量评分低于I组(P0.001)。与I组(50 mAs,FBP)比较,D组(20 mAs,AIDR3D)的有效辐射剂量降低了59.90%,差异有统计学意义(P0.05)。结论超低管电流(20 mAs)扫描结合AIDR3D重建的猪结肠CT图像质量可媲美常规低管电流(50 mAs)扫描结合FBP重建的图像质量,并有效减低辐射剂量。
[Abstract]:Objective to investigate the image quality and radiation dose of ultra-low tube current 3D adaptive iterative dose reduction (AIDR3D) reconstruction for CT porcine colon imaging. Methods Ten segments of porcine colonic polyps were made. 30 nodular polyps with diameter of 1~15mm were found in each segment of porcine colonic mucosa. All the models were scanned by a 640- layer CT machine. The voltage of the tube was 120kV / p, and the current dose was 1050mAs. The reconstructed images of filtered backprojection (FBP) and AIDR3D were obtained. Different tube currents and reconstruction methods were combined with 10 groups of data: group A (10 mABP), group B (10 mAs-AIDR3D), group C (20 mAs,FBP), group D (20mAsAIDR3D), group E (30mAsFBP), group F (30mAsAIDR3D), group G (40mAsAIDR3D), group H (40mAsAIDR3D), group I (50mAsAIDR3D), group J (50mAsAIDR3D). SNR and CNR are used as quantitative indexes, and subjective qualitative evaluation of image quality is carried out. The effective radiation dose was used as an index to compare the radiation dose of each group. Results the noise of AIDR3D images was lower than that of FBP images and CNR were higher than that of FBP images. There was no significant difference between group D and group I (P0. 052) and CNR (P0. 053). The noise of group B (P0. 002) was higher than that of group I (P 0.001). The image quality score of AIDR3D was higher than that of FBP (P0. 05). There was no significant difference between group D and group I (P0. 121). The image quality score of group B was lower than that of group I (P0. 001). Compared with group I (50 mAs,FBP), the effective radiation dose of group D (20 mAs,AIDR3D) decreased 59.90 (P0.05). Conclusion the image quality of porcine colon CT with ultralow tube current (20 mAs) combined with AIDR3D reconstruction is comparable to that of conventional low-tube current (50 mAs) scan and FBP reconstruction, and the radiation dose can be reduced effectively.
【作者单位】：中山大学附属第六医院放射科;清华大学深圳研究生院生物医学工程研究中心;哈佛大学医学院麻州总医院放射科;纽约州立大学石溪分校放射与计算机科学系;
【基金】：国家自然科学基金项目(81230035) 广东省科技计划项目(2011B031800182、2013B051000016)
【分类号】：R816.5

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