Pulmonary microvascular blood volume and emphysema: in vivo link shown in the MESA cohort

Abstract

While the pulmonary microvasculature is thought to be one of the causative factors in emphysema pathogenesis, there is little in vivo evidence in the general population to confirm this. Hermann and colleagues have investigated this link by quantifying the microvascular blood volume using dual-energy computed tomography (DECT) in a diverse, community-based cohort of older adults with and without emphysema.1 Their findings reveal that lower pulmonary microvascular blood volume (PMBV) is linked to emphysema severity, specifically in those with the diffuse emphysema subtype. This association persisted even in participants without a history of smoking or evidence of airflow limitation on spirometry. DECT allows characterisation of materials by measuring attenuation values at two different X-ray energy levels.2 After the administration of iodinated intravenous contrast, DECT can be used to create iodine maps of the lungs at the voxel level, equivalent to pulmonary perfusion, and allows calculation of perfused PMBV.3 In the current study, PMBV is defined as the blood volume in the peripheral 2 cm of lung tissue excluding the area adjacent to the mediastinum, which was selected automatically in order to assess the regions of lung proven …