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目的探讨70 k V联合原始数据域迭代重建(SAFIRE)技术在小儿先天性心脏病(先心病)CT检查中的应用价值。方法收集2014年1月-9月拟行CT检查的30例先心病患儿,按不同的管电压分为A组(80 k V)和B组(70 k V),每组15例。两组患儿均采用西门子128层双源CT进行扫描,对A组患儿的图像采用滤波反投影技术重建,对B组患儿的图像采用SAFIRE技术重建。测量并计算出A组和B组主肺动脉窗层面肺动脉的信噪比、升主动脉的信噪比、肺动脉与竖脊肌的对比噪声比、升主动脉与竖脊肌的对比噪声比;对两组图像进行主观评分并记录辐射剂量指标CT容积剂量指数(CTDIvol)、CT剂量长度乘积(DLP),并计算吸收剂量(ED)。结果 A组和B组主肺动脉窗层面肺动脉的信噪比(14.54±3.77、11.23±2.52)、升主动脉的信噪比(14.76±3.41、12.31±3.47)、肺动脉与竖脊肌的对比噪声比(12.04±3.96、9.18±3.76)、升主动脉与竖脊肌的对比噪声比(12.47±4.59、9.77±4.41)、差异均无统计学意义(P>0.05)。两组图像质量主观评分均≥3分。A组和B组患儿CTDIvol分别为(0.53±0.09)、(0.38±0.03)m Gy,DLP分别为(12.93±1.79)、(6.67±0.72)m Gy·cm,ED分别为(0.34±0.05)、(0.17±0.02)m Sv,两组患儿辐射剂量之间差异有统计学意义(P<0.05)。结论小儿先心病CT检查使用70 k V联合SAFIRE技术可以明显降低辐射剂量,且不降低图像质量,在临床上有较高的应用价值。
Objective To investigate the value of 70 kV combined with original data field iterative reconstruction (SAFIRE) in CT examination of children with congenital heart disease (CHD). Methods Thirty patients with congenital heart disease undergoing CT examination from January to September in 2014 were divided into group A (80 kv) and group B (70 kv) with different tube voltages, 15 cases in each group. Both groups of children were scanned with double-source CT 128-slice Siemens, and the images of children in group A were reconstructed by filtering back projection technique. The images of group B were reconstructed by SAFIRE technique. The signal-to-noise ratio of the pulmonary artery, the signal-to-noise ratio of the ascending aorta, the contrast ratio of the pulmonary artery to the erector spinae, and the contrast ratio of the ascending aorta to the erector spinae were measured and calculated. The two groups of images were subjectively scored and the CT dose volume index (CTDIvol) and CT dose length product (DLP) were recorded and the absorbed dose (ED) was calculated. Results The signal-to-noise ratio (14.54 ± 3.77, 11.23 ± 2.52), the signal-to-noise ratio of ascending aorta (14.76 ± 3.41, 12.31 ± 3.47), the contrast between pulmonary artery and erector spinae (12.04 ± 3.96,9.18 ± 3.76), the ratio of contrast to ascending aorta to erector spinae (12.47 ± 4.59,9.77 ± 4.41), the difference was not statistically significant (P> 0.05). Subjective scores of both groups were ≥ 3 points. The CTDIvol in group A and group B were (0.53 ± 0.09) and (0.38 ± 0.03) m Gy, respectively, and the DLP were (12.93 ± 1.79) and (6.67 ± 0.72) m Gy · cm respectively ), (0.17 ± 0.02) m Sv, the difference between the two groups of children’s radiation dose was statistically significant (P <0.05). Conclusion CT examination in children with congenital heart disease using 70 k V SAFIRE technology can significantly reduce the radiation dose, without reducing the image quality, and has a high clinical value.