目的探讨大矩阵IMR重建技术对肺结节图像质量的影响。方法回顾性分析2018年1月至7月来我院行胸部CT检查的355例病人肺结节CT图像,每位患者均采用飞利浦128排i CT进行扫描,扫描条件为管电压100 kV,参考管电流80 mAs,螺距1.0,球管旋转时间0.8 s,层厚5 mm,层间隔5 mm,分别进行A组512矩阵滤波反投影重建和B组1024大矩阵全迭代重建,测量上中下双肺外侧带噪声值以及主动脉弓、气管分叉处降主动脉、肺底层面降主动脉的噪声值,A、B两组的平均噪声值进行统计学分析,以P<0.05为有统计学差异性,并由两位高年资医生对重建图像进行盲评。结果 A组双肺平均噪声值为42.57±4.83,主动脉平均噪声值为17.34±3.62,B组双肺平均噪声值为23.25±4.36,主动脉平均噪声值为5.65±1.12,A、B两组差异(双肺噪声P<0.05,主动脉噪声P<0.01),有统计学差异,主观评价B组对肺结节显示要优于A组,且两名医生间的一致性均较好(P<0.05)。结论大矩阵IMR重建技术对肺结节图像质量可以进行优化,在低剂量扫描条件下可以得到更高的图像质量。
Objective To investigate the effect of large matrix IMR reconstruction technique on image quality of pulmonary nodules.Methods A retrospective analysis of CT images of 355 patients with chest CT examination from January to July 2018 was performed.Each patient was scanned with Philips 128-row iCT, the scanning condition was tube voltage 100 kV, reference tube current was 80 mAs, pitch was 1.0, bulb rotation time was 0.8 s, layer thickness was 5 mm, layer spacing was 5 mm, respectively.Group A was performed 512 matrix filtered back projection reconstruction(FBP) and group B was performed 1024 large matrix full iteration reconstruction. The noise value of the upper and lower lungs and the noise value of the aortic arch, the descending aorta at the tracheal bifurcation, and the descending aorta of the lung was separately measured. The average noise values of the A and B groups were statistically analyzed. Statistical significance was found with P<0.05, and the reconstructed images were blindly evaluated by two senior physicians. Results The average noise value of the lungs in group A was 42.57±4.83, the average noise value of aorta was 17.34±3.62, the average noise value of the lungs in group B was 23.25±4.36, and the average noise value of aorta was 5.65±1.12. There were significant differences in group differences(P<0.01). There were 86 cases of subjective evaluation in group A and 173 cases in group B. There were statistical differences between the two groups(P<0.05). Conclusion The large matrix IMR reconstruction technique can optimize the image quality of lung nodules and obtain higher image quality under low dose scanning conditions.
China Medical Devices
iterative model reconstruction
filtered back projection