PT  - JOURNAL ARTICLE
AU  - Per Wollmer
AU  - Jonas Jacobson
AU  - Tobias Andersson
AU  - Jakob Löndahl
TI  - The airspace dimension test – A new way to diagnose emphysema?
DP  - 2014 Sep 01
TA  - European Respiratory Journal
PG  - P2134
VI  - 44
IP  - Suppl 58
4099  - http://erj.ersjournals.com/content/44/Suppl_58/P2134.short
4100  - http://erj.ersjournals.com/content/44/Suppl_58/P2134.full
SO  - Eur Respir J2014 Sep 01; 44
AB  - Emphysema is a common feature of chronic obstructive pulmonary disease (COPD). Current diagnostic methods with high specificity for emphysema are computed tomography (CT) and magnetic resonance imaging (MRI) using hyperpolarised gases. CT is relatively expensive and carries a radiation dose. MRI is inaccessible and very expensive. We describe a single-breath technique for measurement of the dimensions of distal airspaces, potentially suitable for diagnosing emphysema.An aerosol containing nanoparticles is inhaled with a vital capacity manoeuvre and the subject holds his breath at maximum inspiration for 10 s. Particle concentration is measured in the inspired gas and in an alveolar sample obtained from the ensuing exhalation. Since nanoparticles are deposited in the lungs purely by diffusion and the time available for diffusion is controlled, the deposited fraction of aerosol (DF) will reflect the diffusion distances in the distal airspaces.We studied 23 normal subjects and 45 patients suffering from a variety of lung diseases and referred for pulmonary function tests. The most common diagnosis was COPD.View this table:As a group, the patients showed airflow obstruction. The range of DF found in normal subjects was very narrow. The ADF was lower in the patients than in normal subjects, compatible with increased diffusion distances in distal airspaces.This preliminary study shows promise for the Airspace Dimension Test as a diagnostic test. Further studies are required to elucidate its relation to emphysema.