TY - JOUR T1 - Unfolding the mechanisms of progression of pulmonary emphysema in COPD JF - European Respiratory Journal JO - Eur Respir J SP - 801 LP - 803 DO - 10.1183/09031936.00030112 VL - 40 IS - 4 AU - Riccardo Pellegrino AU - Andrea Antonelli Y1 - 2012/10/01 UR - http://erj.ersjournals.com/content/40/4/801.abstract N2 - Until a quarter of a century ago, diagnosing pulmonary emphysema in clinical practice was a very difficult task, as the definition of the disease was based only on the pathological criteria of destruction of the parenchyma distal to the terminal bronchioles in the absence of inflammation and/or fibrosis [1]. Lung function tests could be of help but this was only possible when airflow obstruction was severe, lung volumes increased above normal and diffusing capacity of the lung very low, i.e. too late to identify the disease in the early stages. Similarly, chest radiography could be of help for this purpose but only when lung fields were hyperlucent with blebs and no or few arteries, the diaphragm was flat, and anteroposterior diameters were increased. Again, this was when the disease was too advanced. A major breakthrough occurred with the advent of high-resolution computed tomography (HRCT), a tool that proved to be very sensitive in assessing the pathology on its centrilobular, panlobular and paraseptal features, and its distribution across the lungs [2, 3]. The results were so impressive that the technique was soon widely used in both clinical practice and research. In addition to assisting in the clinical diagnosis of the disease condition, HRCT brought major advancements as for the pathogenesis of the chronic obstructive pulmonary disease (COPD), and nowadays plays a crucial role with respect to lung volume reduction surgery [4] and transplantation [5].Recent studies have focused on HRCT as a tool to assess the progression of the disease. Most of them have been conducted in α1-antitrypsin deficiency with the aim of identifying the lung densitometry parameters that best reflect the progression of the disease [6] compared with classical functional parameters, such as forced expiratory volume in … ER -