2-deoxy-2-[ 18F] fluoro-D-glucose uptake in intercostal respiratory muscles on positron emission tomography/computed tomography: smokers versus nonsmokers

The purpose of this study was to determine the frequency of 2-deoxy-2-[ 18F]fluoro-D-glucose (FDG) uptake in the intercostal respiratory muscles (ICM) of smokers versus nonsmokers using positron emission tomography (PET). Ninety-six whole-body PET/computed tomography (CT) scans were retrospectively reviewed; 61 studies were from smokers and 35 from nonsmokers. The ICM uptake from the lung apices to the level of the carina was visually scored with respect to FDG intensity as follows: 0 = uptake less than or equal to lung uptake; 1 = greater than lung, but less than mediastinal blood pool; 2 = equal to mediastinal blood pool; and 3 = greater than mediastinal blood pool. In smokers, 30 out of 61 (49.2%) PET/CT scans had uptake that localized to ICM, compared to 3/35 (8.6%) studies in nonsmokers. Average ICM uptake was significantly different between smokers and nonsmokers (0.787 ± 0.933 and 0.143 ± 0.494, respectively; P < 0.01). Increased FDG uptake in ICM is a physiologic pattern of uptake that is frequently seen and is more common in smokers.