ASIR-V重建算法在胸部低剂量CT诊断肺结节中的临床价值  

Clinical value of a new generation adaptive statistical iterative reconstruction(ASIR-V)in the diagnosis of pulmonary nodule in low-dose chest CT

作　　者：唐慧 时宏[1] 刘婷 和鸿[1] 刘为[1] 薛久华[1] TANG Hui;SHI Hong;LIU Ting;HE Hong;LIU Wei;XUE Jiuhua(Department of Radiology,Xi'an No.1 Hospital,Shaanxi Xi'an 710002,China.)

机构地区：[1]西安市第一医院医学影像科,陕西西安710002

出　　处：《现代肿瘤医学》2021年第13期2329-2333,共5页Journal of Modern Oncology

基　　金：陕西省西安市卫健委基金项目资助青年培养项目(编号:2020qn04)。

摘　　要：目的:探讨胸部低剂量CT结合基于多模型的迭代重建算法(ASIR-V)在肺结节诊断中的临床价值。方法:收集行Revolution CT胸部平扫的肺结节患者40例。患者首次检查时先采用常规剂量胸部CT扫描,预设噪声指数为14 HU,图像重建采用滤波反投影法(FBP);若发现肺结节者,于肺结节局部层面进行低剂量靶扫描,预设噪声指数为24 HU,图像采用60%ASIR-V算法进行重建。记录两种扫描模式下肺结节的检出数,测量肺结节的大小、CT值、噪声值以及肺组织CT值和噪声值,并计算肺结节的信噪比(SNR)和对比噪声比(CNR)。两名有经验的放射科医师采用5分法对两种扫描模式下整体图像质量以及部分肺结节的特殊形态学征象进行主观评分。记录两种扫描模式中患者的CT容积剂量指数(CTDIvol)、剂量长度乘积(DLP),并计算有效剂量(ED)。结果:常规剂量扫描ED为(3.20±1.14)mSv,低剂量扫描ED为(1.64±0.29)mSv,辐射剂量减低约48.8%。常规剂量扫描共检出108个肺结节,低剂量扫描共检出107个肺结节,低剂量CT扫描肺结节检出率为99.07%。低剂量60%ASIR-V图像和常规剂量FBP图像在肺结节的大小、CT值、SD值、SNR及CNR方面差异均无统计学意义(P>0.05)。两名医师对两组图像的主观评分差异亦无统计学意义(P>0.05)。结论:在低剂量CT扫描中,运用60%ASIR-V算法对于肺结节的检出、肺结节形态学特征的显示与常规剂量FBP图像质量差异不大,但其辐射剂量明显降低。Objective:To evaluate the clinical value of low-dose chest CT combined with the new generation adaptive statistical iterative reconstruction(ASIR-V)algorithm in the diagnosis of pulmonary nodule.Methods:40 patients with pulmonary nodules underwent chest CT using Revolution CT.The patients were first scanned with standard-dose at a noise index of 14 HU,and the images were reconstructed with FBP algorithm.If pulmonary nodules were found,a low-dose targeted scan,with a noise index of 24 HU,was performed localized on the nodules,and the images were reconstructed with 60%ASIR-V.The detection rate of pulmonary nodules in the two scanning modes was recorded.The size of nodules,CT value and standard deviation(SD)of nodules were measured.The signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were also calculated.Two experienced radiologists used a 5-point method to score the overall image quality and the morphological signs of the partial pulmonary nodules.The volumetric CT dose index(CTDIvol),and dose length product(DLP)were recorded and the effective dose(ED)was calculated of the two scanning modes.Results:ED of the standard-dose scan was(3.20±1.14)mSv,and that of low-dose scan was(1.64±0.29)mSv,with 48.8%reduction.107 of the 108 pulmonary nodules were detected in the low-dose targeted scan,resulting in 99.07%detection rate.There was no difference between the low-dose 60%ASIR-V images and standard-dose FBP images for the size,CT value,SD value,SNR and CNR of nodules(all P>0.05).There was no difference in the subjective scores between the two scanning modes(P>0.05).Conclusion:The low-dose CT scan combined with 60%ASIR-V algorithm is of comparable value in the detection of pulmonary nodules and the display of the morphological signs of nodules when compared with the FBP images obtained by standard-dose scan.

关 键 词：计算机断层扫描 基于多模型的迭代重建算法 胸部 图像质量 

分 类 号：R734.2[医药卫生—肿瘤]