双低条件下结合最适迭代权重在冠状动脉3D打印技术中应用

目的比较不同权重自适应统计迭代重建(ASIR)技术在低浓度对比剂及低辐射剂量条件下行冠状动脉3D打印的可行性。方法选择2016年3—12月沈阳军区总医院收治的疑诊为冠状动脉心脏病并行冠状动脉CT成像(CCTA)检查的患者20例为研究对象。体质量指数(BMI)20~25 kg/m2,在双低条件下(100 k Vp及270 mg I/ml碘克沙醇对比剂)行前瞻性心电门控技术CCTA扫描,扫描完成后对图像进行滤波反投影法(FBP)及不同权重ASIR重建(20%、40%、60%、80%、100%),并将数据传至3D打印机,行冠状动脉3D建模打印,对3D打印产物进行主客观评价。结果相对于FBP重建算法,20%、40%、60%、80%、100%ASIR图像噪声分别降低9%、21%、30%、45%、52%(P<0.05),信号噪声比(SNR)、对比噪声比(CNR)分别提高约6%、17%、38%、56%、72%及12%、22%、42%、56%、66%(P<0.05)。不同权重ASIR重建图像CT值比较,差异无统计学意义(P>0.05)。行FBP,20%、40%、60%、80%、100%ASIR的3D打印产物主观评分分别为1.6、2.0、4.0、4.1、2.1、1.3分,组间比较,差异有统计学意义(P<0.05)。权重设置在40%、60%ASIR的3D打印产物质量具有最高主观评分,打印冠状动脉的质量最好。结论在双低条件下及ASIR重建技术行冠脉3D打印,相对于FBP重建算法,不同权重ASIR图像在40%、60%时,3D打印产物的质量具有最高主观评分,图像质量最好,同时可大幅度降低患者所受辐射剂量。

Coronary artery 3D printing technology by using low dose of radiation and contrast agent combined with optimizing adaptive statistical iterative reconstruction technique

Objective To compare the feasibility of using different ASIR reconstruction technique combine low dose and low contrast agent apply coronary artery 3D printing.Methods A retrospective study was performed on 20 patients whose BMI from 20 to 25 kg/m2 with suspected coronary disease underwent coronary artery 3D printing from March to December 2016.Coronary artery CTA scanning parameters(100 kVp,contrast media:Visopaque 270 mgI/ml)and group information results were as the following:raw data reconstructed with different percentage of ASIR(0%,20%,40%,60%,80% and 100%),then transmitted data to 3D printer underwent coronary artery 3D printing.The 3D printing products of different weight conditions underwent subjective and objective evaluation was performed.Results In comparison with FBP(0% ASIR),the use of 20%,40%,60%,80% and 100% ASIR resulted in reduced image noise between groups 9%,21%,30%,45% and 52%,respectively(P<0.05).ASIR also increased SNR and CNR between groups 6%,17%,38%,56%,72% and 12%,22%,42%,56%,66%,respectively(P<0.05).There was no significant difference in different weight ASIR reconstruction of CT DICOM data CT between groups(P>0.05).To perform FBP,20%,40%,60%,80% and 100% ASIR in the subjective scores 1.6,2.0,4.0,4.1,2.1 and 1.3,respectively(P<0.05).Reconstruction using 40% and 60% ASIR 3D printing product quality had the highest the subjective scores,display the best quality for coronary artery 3D printing.Conclusion Under the condition of double low and ASIR reconstruction technique to perform 3D printing,compared with FBP reconstruction,reconstruction using 40% and 60% ASIR has the highest subjective scores of imaging quality in coronary artery 3D printing,and apparently reduce the radiation dose to patients.