CT Imaging-Based Low-Attenuation Super Clusters in Three Dimensions and the Progression of Emphysema

Chest: The Journal of Circulation, Respiration and Related Systems

Susumu Sato^3¹  Dean Zeldich^1²  Jarred R. Mondoñedo^1,2³  Tsuyoshi Oguma^3⁴  Shigeo Muro^4⁵  Adam H. Sonnenberg^5⁶ 

[1] Boston University School of Medicine, Boston, MA^2;Department of Bioengineering, Northeastern University, Boston, MA^6;Department of Biomedical Engineering, Boston University College of Engineering, Boston, MA^1;Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan^3;Department of Respiratory Medicine, Nara Medical University, Nara, Japan^4;Department of Systems Engineering, Boston University College of Engineering, Boston, MA^5

关键词: 3-D reconstruction;    computational modeling;    mechanical stress;    power law;    2-D;    two-dimensional;    3-D;    three-dimensional;    Dlco;    diffusing capacity of the lung for carbon monoxide;    GOLD;    Global Initiative for Chronic Obstructive Lung Disease;    HU;    Hounsfield unit;    LAA;    low-attenuation area;    LAN;    number of LAVs;    LAV;    low-attenuation volume;   

DOI  :  10.1016/j.chest.2018.09.014

学科分类：呼吸医学

来源: American College of Chest Physicians

【 摘 要 】

Background Distributions of low-attenuation areas in two-dimensional (2-D) CT lung slices are used to quantify parenchymal destruction in patients with COPD. However, these segmental approaches are limited and may not reflect the true three-dimensional (3-D) tissue processes that drive emphysematous changes in the lung. The goal of this study was to instead evaluate distributions of 3-D low-attenuation volumes, which we hypothesized would follow a power law distribution and provide a more complete assessment of the mechanisms underlying disease progression. Methods CT scans and pulmonary function test results were acquired from an observational database for N = 12 patients with COPD and N = 12 control patients. The data set included baseline and two annual follow-up evaluations in patients with COPD. Three-dimensional representations of the lungs were reconstructed from 2-D axial CT slices, with low-attenuation volumes identified as contiguous voxels Results Low-attenuation sizes generally followed a power law distribution, with the exception of large, individual outliers termed "super clusters," which deviated from the expected distribution. Super cluster volume was correlated with disease severity (% total low attenuation, ρ = 0.950) and clinical measures of lung function including FEV₁ (ρ = –0.849) and diffusing capacity of the lung for carbon monoxide Dlco (ρ = –0.874). To interpret these results, we developed a personalized computational model of super cluster emergence. Simulations indicated disease progression was more likely to occur near existing emphysematous regions, giving rise to a biomechanical, force-induced mechanism of super cluster growth. Conclusions Low-attenuation super clusters are defining, quantitative features of parenchymal destruction that dominate disease progression, particularly in advanced COPD.

【 授权许可】

CC BY