超低剂量CT能谱纯化技术定量肺气肿  

Feasibility of ultralow-dose CT with selective photon shield in quantification of emphysema

作　　者：高燕莉[1] 翟晓力[1] 李坤[1] 徐晓莉 张卫国[1] 黄克武[2] GAO Yanli;ZHAI Xiaoli;LI Kun;XU Xiaoli;ZHANG Weiguo;HUANG Kewu(Department of Radiology,Beijing Chao-yang Hospital,Capital Medical University,Beijing 100020,China;Department of Pulmonary and Critical Care Medicine,Beijing Chao-yang Hospital,Capital Medical University,Beijing 100020,China)

机构地区：[1]首都医科大学附属北京朝阳医院放射科,北京100020 [2]首都医科大学附属北京朝阳医院呼吸与危重症医学科,北京100020

出　　处：《中国医学影像技术》2021年第3期375-379,共5页Chinese Journal of Medical Imaging Technology

基　　金：国家重点研发计划(2016YFC0901102)。

摘　　要：目的探讨超低剂量CT(ULDCT)能谱纯化(SPS)技术用于定量诊断肺气肿的可行性。方法对45例慢性阻塞性肺疾病(COPD)患者分别行常规低剂量CT(LDCT)及ULDCT检查,ULDCT采用锡片预滤器达到能谱纯化。以滤波反投影(FBP)重建LDCT图像(LDCT-FBP组),分别以FBP(ULDCT-FBP组)、高级模型迭代重建(ADMIRE)3级(ULDCT-ADMIRE 3组)和5级(ULDCT-ADMIRE 5组)重建ULDCT图像。比较各组图像肺气肿指数(EI)、15%肺衰减值(Perc 15)、平均肺密度(MLD)、全肺体积(TLV)及图像质量主观评分和图像噪声,以及LDCT与ULDCT有效辐射剂量(ED)。结果相比LDCT-FBP组,ULDCT-FBP组EI增加2.34%(P<0.01)、Perc 15降低5 HU(P<0.01),ULDCT-ADMIRE 5组EI降低1.44%(P<0.01)、Perc 15增加3 HU(P<0.01);ULDCT-ADMIRE 3组与LDCT-FBP组间各定量参数差异均无统计学意义(P均>0.05)。LDCT-FBP组图像质量主观评分均高于其余3组(P均<0.05),ULDCT-ADMIRE 3组和ULDCT-ADMIRE 5组图像质量主观评分均达诊断肺气肿标准。LDCT-FBP组图像噪声低于ULDCT-FBP组及ULDCT-ADMIRE 3组(P均<0.05),与ULDCT-ADMIRE 5组差异无统计学意义(P>0.05)。ULDCT的ED为(0.20±0.06)mSv,较LDCT降低88.64%(P<0.01)。结论ULDCT SPS联合ADMIRE(3级)迭代重建可用于定量诊断肺气肿,并能大幅度降低辐射ED。Objective To explore the feasibility of ultralow-dose CT(ULDCT)with selective photon shield(SPS)in quantification of emphysema.Methods A total of 45 patients with chronic obstructive pulmonary disease(COPD)were enrolled and underwent both low-dose CT(LDCT)and ULDCT.ULDCT was purified with single-energy using tin filtration.LDCT images were reconstructed with filtered back projection(FBP,LDCT-FBP group).For ULDCT,images were reconstructed with FBP(ULDCT-FBP group),level 3(ULDCT-ADMIRE 3 group)and level 5(ULDCT-ADMIRE 5 group)of advanced modeled iterative reconstruction(ADMIRE).Emphysema index(EI),the 15th percentile of lung attenuation(Perc 15),the mean lung attenuation(MLD),total lung volume(TLV)as well as subjective scoring of imaging quality and image noise were compared among groups,and the effective dose(ED)of radiation was compared between LDCT and ULDCT.Results Compared with LDCT-FBP group,EI increased by 2.34%and Perc 15 decreased by 5 HU(all P<0.01)in ULDCT-FBP group,while EI decreased by 1.44%and Perc 15 increased by 3 HU(all P<0.01)in ULDCT-ADMIRE 5 group.There was no statistical significance of quantitative parameters between ULDCT-ADMIRE 3 groups and LDCT-FBP group(all P>0.05).The subjective scoring of imaging quality in LDCT-FBP group was higher than that in the other 3 groups(all P<0.05).The subjective scoring of imaging quality in both ULDCT-ADMIRE 3 group and ULDCT-ADMIRE 5 group reached the diagnostic imaging standards of emphysema.The image noise of LDCT-FBP group was lower than that of ULDCT-FBP group and ULDCT-ADMIRE 3 group(both P<0.05),while no significant difference was found with that of ULDCT-ADMIRE 5 group(P>0.05).ED of ULDCT was(0.20±0.06)mSv,88.64%lower than that of LDCT(P<0.01).Conclusion ULDCT with SPS combining ADMIRE(level 3)iterative reconstruction was feasible for quantification of emphysema with obvious reduction of ED.

关 键 词：肺气肿 体层摄影术 X线计算机 质量控制 

分 类 号：R563.3[医药卫生—呼吸系统] R814.42[医药卫生—内科学]