Understanding Lung Acinar Micromechanics in Health and Disease: Linking Quantitative Imaging and Organ Scale Mechanics by Computational Modeling

The structure of the lung has evolved to optimize gas exchange which is the primary function of the pulmonary system. In this context, the acinus is the functional unit in which gas and blood are brought together for uptake of oxygen and elimination of carbon dioxide. During respiration the lung parenchyma is subjected to cyclic strain which challenges the tissue components and requires mechanisms by which the tissue can cope with the related stresses and strains without sustaining injury. The dynamic changes in acinar microarchitecture during respiration, also referred to as acinar micromechanics, are an area of respiratory physiology and pathophysiology that is not entirely understood. This crucial knowledge gap results from the fact that there are no non-destructive imaging techniques which allow a real time visualization of acinar microarchitecture in vivo with cellular-scale resolution. However, a detailed understanding of the acinar micromechanics is of high importance because organ-scale pulmonary macromechanics are a consequence of the microscale properties. This emergent behavior across length scales is a critically important driver of lung mechanical function that has yet to be fully described. Furthermore, pathological alterations at the micromechanical level have the capacity to potentiate lung injury and fibrosis through mechanisms including heterogeneous alveolar ventilation, tethering-induced stress concentrations, atelectrauma, and volutrauma. These mechanisms are most commonly recognized in the context of ventilator-induced lung injury where the organ-scale pressures and flows delivered by the mechanical ventilator should be optimized to minimize injury caused by microscale stresses and strains. In addition, micromechanical pathology also plays an important role in fibrotic lung diseases such as Idiopathic Pulmonary Fibrosis. As such, quantification of microscale structure and function is of utmost importance to understanding the initiation and progression of pulmonary disease.

Hence, this Research Topic entitled “Understanding Lung Acinar Micromechanics in Health and Disease: Linking Quantitative Imaging and Organ Scale Mechanics by Computational Modeling” aims to publish original research as well as review articles covering imaging, simulation, and the physiology of acinar micromechanics in healthy and diseased lungs.