Reduced-dose chest CT with 3D automatic exposure control vs. standard chest CT: Quantitative assessment of emphysematous changes in smokers鈥?lung parenchyma

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• 作者：Hisanobu Koyama^a ; ^{hkoyama@med.kobe-u.ac.jp} ; ^{hisanobu19760104@yahoo.co.jp} ; Yoshiharu Ohno^a ; ¹ ; ^{yosirad@kobe-u.ac.jp} ; Youichi Yamazaki^b ; ² ; ^{y.yamazk@sahs.med.osaka-u.ac.jp} ; Keiko Matsumoto^a ; ¹ ; ^{palm_kei@yahoo.co.jp} ; Yumiko Onishi^a ; ¹ ; Daisuke Takenaka^a ; ¹ ; ^{daisuket@med.kobe-u.ac.jp} ; Takeshi Yoshikawa^a ; ¹ ; ^{yoshikaw@med.kobe-u.ac.jp} ; Mizuho Nishio^a ; ¹ ; ^{jurader@yahoo.co.jp} ; Sumiaki Matsumoto^a ; ¹ ; ^{sumatsu@med.kobe-u.ac.jp} ; Kenya Murase^b ; ² ; ^{murase@sahs.med.osaka-u.ac.jp} ; Yoshihiro Nishimura^c ; ³ ; ^{nishiy@med.kobe-u.ac.jp} ; Kazuro Sugimura^a ; ¹ ; ^{sugimura@med.kobe-u.ac.jp}
• 关键词：Lung ; CT ; Radiation dose ; Pulmonary emphysema
• 刊名：European Journal of Radiology
• 出版年：2012
• 期刊代码：93_0720048x
• 类别：med
• 出版时间：June, 2012
• 卷：81
• 期：6
• 页码：1330-1334
• 文件大小：623 K

摘要

Objectives

To determine the capability of reduced-dose chest CT with three-dimensional (3D) automatic exposure control (AEC) on quantitative assessment of emphysematous change in smoker鈥?lung parenchyma, compared to standard chest CT.

Methods

Twenty consecutive smoker patients (mean age 62.8 years) underwent CT examinations using a standard protocol (150 mAs) and a protocol with 3D-AEC. In this study, the targeted standard deviations number was set to 160. For quantitative assessment of emphysematous change in lung parenchyma in each subject using the standard protocol, a percentage of voxels less than 鈭?50 HU in the lung (%LAA_鈭?50) was calculated. The 3D-AEC protocol's%LAA was computed from of voxel percentages under selected threshold CT value. The differences of radiation doses between these two protocols were evaluated, and%LAAs_鈭?50 was compared with the 3D-AEC protocol%LAAs.

Results

Mean dose length products were 780.2 卤 145.5 mGy cm (standard protocol), and 192.0 卤 95.9 (3D-AEC protocol). There was significant difference between them (paired Student's t test, p < 0.00001). Meanwhile, only setting 鈭?60 HU yielded no significant difference (paired Student's t test, p = 0.32) between%LAAs_鈭?50 and 3D-AEC protocol%LAAs. In adopting the feasible threshold CT values of the 3D-AEC protocol, the 3D-AEC protocol%LAAs were significantly correlated with%LAAs_鈭?50 (r = 0.98, p < 0.001) and limits of agreement from Bland-Altman analysis was 0.52 卤 4.3%.

Conclusions

Changing threshold CT values demonstrated that reduced-dose chest CT with 3D-AEC can substitute for the standard protocol in assessments of emphysematous change in smoker鈥?lung parenchyma.