정상 폐 기능의 비흡연자에서 흉부 전산화단층촬영 덴시토메트리 = CT Densitometry of the Lung in Healthy Nonsmokers with Normal Pulmonary Function

다국어 초록 (Multilingual Abstract)

Purpose: To investigate the upper normal limit of low attenuation area% in healthy nonsmokers.
Materials and Methods: A total of 36 nonsmokers with normal pulmonary function test underwent a CT scan. Six thresholds (-980 - -930 HU) on inspiration CT and two thresholds (-950 and -910 HU) on expiration CT were used for obtaining low attenuation area%. The mean lung density was obtained on both inspiration CT and expiration CT. Descriptive statistics of low attenuation area% and the mean lung density, evaluation of difference of low attenuation area% and the mean lung density in both sex and age groups, analysis of the relationship between demographic information and CT parameters were performed.
Results: Upper normal limit for low attenuation area% was 12.96% on inspiration CT (-950 HU) and 9.48% on expiration CT (-910 HU). Upper normal limit for the mean lung density was -837.58 HU on inspiration CT and 686.82 HU on expiration CT. Low attenuation area% and the mean lung density showed no significant differences in both sex and age groups. Body mass index (BMI) was negatively correlated with low attenuation area% on inspiration CT (-950 HU, r = -0.398, p = 0.016) and positively correlated with the mean lung density on inspiration CT (r = 0.539, p = 0.001) and expiration CT (r = 0.432, p = 0.009). Age and body surface area were not correlated with low attenuation area% or the mean lung density.
Conclusion: Low attenuation area% on CT densitometry of the lung could be found in healthy nonsmokers with normal pulmonary function, and showed negative association with BMI. Reference values, such as range and upper normal limit for low attenuation area% in healthy subjects could be helpful in quantitative analysis and follow up of early emphysema, using CT densitometry of the lung.

국문 초록 (Abstract)

목적: 정상 폐 기능 비흡연 성인의 흉부 전산화단층촬영에서 다양한 역치의 저감쇠영역%의 범위와 정상 상한치를 제시하고자 하였다.
대상과 방법: 흉부 전산화단층촬영을 시행 받은 정상 폐 기능 비흡연 성인 36명에 대해 흡기시 6개의 역치(-980~-930 HU)와 호기시 2개의 역치(-950, -910 HU)에서의 저감쇠영역%와 흡기, 호기시 폐실질평균농도를 구하였다. 저감쇠영역%와 폐실질평균농도의 기술통계를 시행하고 성별과 연령구역에 따른 차이를 비교하였으며, 연령, 체표면적, 체질량지수와의 상관성을 분석하였다.
결과: 흡기시 -950 HU 역치의 저감쇠영역%의 평균, 정상 상한치값(95th percentile)은 5.24%, 12.96%, 호기시 -910 HU 역치에서는 2.06%, 9.48%, 흡기시 폐실질평균농도는 -866.16 HU, -837.58 HU, 호기시 폐실질평균농도는 -737.80 HU, -686.82 HU였다. 성별과 연령구역 간 저감쇠영역%와 폐실질평균농도는 통계학적 차이가 없었다. 체질량지수는 흡기시 -970~-930 HU 역치의 저감쇠영역%들과 음의 상관성을(-950 HU, p = 0.016), 흡기와 호기 폐실질평균농도와 양의 상관성을 보였다(p = 0.001, p = 0.009).
결론: 정상 폐 기능의 비흡연자에서도 특정 역치를 이용한 덴시토메트리에서 저감쇠영역%가 나타날 수 있고, 체질량지수와 반비례하여 증가하였다. 정상 성인에서 저감쇠영역%의 범위와 정상 상한치의 정보가 덴시토메트리를 이용한 조기 폐기종의 정량분석과 추적관찰에서의 진행 정도를 평가하는 데에 도움을 줄 것으로 생각한다.

참고문헌 (Reference)

1 이현주, "만성폐쇄성폐질환 환자를 대상으로 흡기와 호기 시에 시행된 전산화단층촬영에서 폐기종지수를 구하기 위한 역치에 대한 연구: 폐기능검사와의 연관도에의 영향" 대한영상의학회 59 (59): 99-106, 2008

2 Müller NL, "“Density mask”. An objective method to quantitate emphysema using computed tomography" 94 : 782-787, 1988

3 Marsh S, "Utility of lung density measurements in the diagnosis of emphysema" 101 : 1512-1520, 2007

4 Gevenois PA, "The effects of age, sex, lung size, and hyperinflation on CT lung densitometry" 167 : 1169-1173, 1996

5 "Standards for the diagnosis and care of patients with chronic obstructive pulmonary disease. American Thoracic Society" 152 (152): S77-S121, 1995

6 Chae EJ, "Slope of emphysema index: an objective descriptor of regional heterogeneity of emphysema and an independent determinant of pulmonary function." 194 : W248-W255, 2010

7 "Quantitative assessment of emphysema, air trapping, and airway thickening on computed tomography" SPRINGER 186 : 157-165, 2008

8 Park KJ, "Quantitation of emphysema with three-dimensional CT densitometry: comparison with two-dimensional analysis, visual emphysema scores, and pulmonary function test results" 211 : 541-547, 1999

9 Kinsella M, "Quantitation of emphysema by computed tomography using a “density mask” program and correlation with pulmonary function tests" 97 : 315-321, 1990

10 Bankier AA, "Pulmonary emphysema: subjective visual grading versus objective quantification with macroscopic morphometry and thin-section CT densitometry" 211 : 851-858, 1999

11 Gevenois PA, "Pulmonary emphysema: quantitative CT during expiration" 199 : 825-829, 1996

12 Madani A, "Pulmonary emphysema: objective quantification at multi-detector row CT--comparison with macroscopic and microscopic morphometry" 238 : 1036-1043, 2006

13 Stolk J, "Progression parameters for emphysema: a clinical investigation" 101 : 1924-1930, 2007

14 Stoel BC, "Optimization and standardization of lung densitometry in the assessment of pulmonary emphysema" 39 : 681-688, 2004

15 Coxson HO, "Early emphysema in patients with anorexia nervosa" 170 : 748-752, 2004

16 Stolk J, "Correlation between annual change in health status and computer tomography derived lung density in subjects with alpha1-antitrypsin deficiency" 58 : 1027-1030, 2003

17 Gevenois PA, "Comparison of computed density and microscopic morphometry in pulmonary emphysema" 154 : 187-192, 1996

18 Gevenois PA, "Comparison of computed density and macroscopic morphometry in pulmonary emphysema" 152 : 653-657, 1995

19 Irion KL, "CT quantification of emphysema in young subjects with no recognizable chest disease" 192 : W90-W96, 2009

20 Ogawa E, "Body mass index in male patients with COPD: correlation with low attenuation areas on CT" 64 : 20-25, 2009

21 Gillooly M, "Airspace size in lungs of lifelong non-smokers: effect of age and sex" 48 : 39-43, 1993

22 Standardization of Spirometry, "1994 Update. American Thoracic Society" 152 : 1107-1136, 1995