Rofo 2010; 182 - A3
DOI: 10.1055/s-0030-1268288

Synchrotron-based Micro-CT Imaging of the Human Lung Acinus

R Moritz 1, AC Langheinrich 1, HD Litzlbauer 1, K Korbel 1, TL Kline 3, SM Jorgensen 3, DR Eaker 3, RM Bohle 2, EL Ritman 3
  • 1Department of Radiology, Justus-Liebig University Gießen and Marburg GmbH
  • 2Department of Pathology, University of Homburg/Saar
  • 3Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN, USA

Aim: Structural data about the human lung fine structure are mainly based on stereological methods applied to serial sections. The purpose of our study was to generate a complete data set of the intact 3-dimensional architecture of the human acinus using high-resolution synchrotron-based micro-CT (synMCT).

Material and Methods: A human lung was inflation-fixed by formaldehyde ventilation and then scanned in a 64-slice CT over its apex to base extent. Lung samples (8-mm diameter, 10-mm height, n=12) were punched out, stained with osmium tetroxide, and scanned using synMCT at (4µm)3 voxel size. The lung functional unit (acinus, n=8) was segmented from the 3D tomographic image using an automated tree-analysis software program. Morphometric data of the lung were analyzed by ANOVA

Results: Intraacinar airways branching occurred over 11 generations. The mean acinar volume was 131.3±29.2mm3 (range 92.5–171.3mm3) and the mean acinar surface was calculated with 1012±26cm2. The airway internal diameter (starting from the bronchiolus terminalis) decreases distally from 0.66±0.04mm to 0.34±0.06mm (p<0.001) and remains constant after the 7th generation (p<0.5). The length of each generation ranges between 0.52–0.93mm and did not show significant differences between the second and 11th generation. The branching angle between daughter branches varies between 113–134° without significant differences between the generations (p<0.3).

Discussion: Our study presents the first x-ray based three-dimensional segmentation of the human acinus using synchrotron-based micro-CT.

Conclusion: This study demonstrates the feasibility of quantitating the 3D structure of the human acinus at the spatial resolution readily achievable using synMCT.

Keywords: Lung, Acinus, micro-CT