Kizhakke Puliyakote Abhilash S, Vasilescu Dragoş M, Sen Sharma Kriti, Wang Ge, Hoffman Eric A
Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa;
Department of Radiology, University of Iowa, Iowa City, Iowa;
J Appl Physiol (1985). 2016 Jun 15;120(12):1402-9. doi: 10.1152/japplphysiol.00923.2015. Epub 2016 Mar 3.
We seek to establish a method using interior tomographic techniques (Xradia MicroXCT-400) for acinar morphometric analysis using the pathway center lines from micro X-ray computed tomographic (Micro-CT) images as the road map. Through the application of these techniques, we present a method to extend the atlas of murine lungs to acinar levels and present a comparison between two age groups of the C57BL/6 strain. Lungs fixed via vascular perfusion were scanned using high-resolution Micro-CT protocols. Individual acini were segmented, and skeletonized paths to alveolar sacs from the entrance to the acinus were formed. Morphometric parameters, including branch lengths, diameters, and branching angles, were generated. Six mice each, at two age groups (∼20 and ∼90 wk of age), were studied. Additive Gaussian noise (0 mean and SD 1, 2, 5, and 10) was used to test the robustness of the analytical method. Noise-based variations were within ±6 μm for branch lengths and ±5 μm for diameters. At a noise level of 10, errors increased. Branch diameters were less susceptible to noise than lengths. There was >95% center line overlap across all noise levels. The measurements obtained using the center lines as a road map were not affected by added noise. Acini from younger mice had smaller branch diameters and lengths at all generations without significant differences in branching angles. The relative distribution of volume in the alveolar ducts was similar across both age groups. The method has been demonstrated to be repeatable and robust to image noise and provides a new, nondestructive technique to assess and compare acinar morphometry quantitatively.
我们试图建立一种方法，使用内部断层扫描技术（Xradia MicroXCT - 400），以微X射线计算机断层扫描（Micro - CT）图像中的路径中心线作为路线图进行腺泡形态计量分析。通过应用这些技术，我们提出了一种将小鼠肺图谱扩展到腺泡水平的方法，并对C57BL/6品系的两个年龄组进行了比较。通过血管灌注固定的肺使用高分辨率Micro - CT协议进行扫描。对单个腺泡进行分割，并形成从腺泡入口到肺泡囊的骨架化路径。生成了包括分支长度、直径和分支角度在内的形态计量参数。研究了两个年龄组（约20周龄和约90周龄）的各6只小鼠。使用加性高斯噪声（均值为0，标准差为1、2、5和10）来测试分析方法的稳健性。基于噪声的变化对于分支长度在±6μm以内，对于直径在±5μm以内。在噪声水平为10时，误差增加。分支直径比长度对噪声更不敏感。在所有噪声水平下，中心线重叠率>95%。使用中心线作为路线图获得的测量不受添加噪声的影响。年轻小鼠的腺泡在所有代次中分支直径和长度都较小，分支角度没有显著差异。两个年龄组肺泡管中的体积相对分布相似。该方法已被证明具有可重复性，对图像噪声具有稳健性，并提供了一种新的无损技术来定量评估和比较腺泡形态计量学。
