Hell J Nucl Med
-
Our aim was to quantify the degree of pulmonary inflammation associated with centrilobular emphysema using fluoro-18-2-fluoro-2-deoxy-D-glucose positron emission tomography ((18)F-FDG-PET) and diagnostic unenhanced computed tomography (CT) based image segmentation and partial volume correction. Forty-nine subjects, with variable amounts of centrilobular emphysema, who had prior diagnostic unenhanced chest CT and either (18)F-FDG-PET or (18)F-FDG-PET/CT were selected. Lung parenchymal volume (L) (in cm³) excluding large and small pulmonary vessels, emphysema volume (E) (in cm³) based on a -910HU threshold, fraction of lung emphysema (F=E/L), and mean attenuation (HU) of non-emphysematous lung parenchyma (A) were calculated from CT images using the image analysis software 3DVIEWNIX. ⋯ In conclusion, the degree of pulmonary inflammation increases with emphysema severity based on (18)F-FDG-PET or (18)F-FDG-PET/CT assessment, but is only detectable when (18)F-FDG uptake is corrected for the partial volume effect based on data provided from diagnostic chest CT images. These results support the notion that pulmonary inflammation plays an important role in the pathophysiology of emphysema. This novel image analysis approach has great potential for practical, accurate, and precise combined structural-functional PET quantification of pulmonary inflammation in patients with emphysema or other pulmonary conditions, although further validation and refinement will be required.