Avid FDG Uptake in the Right Ventricle Coupled with Enhanced Intercostal Muscle Hypermetabolism in Pneumoconiosis

摘要

Avid FDG uptake in the right ventricle (RV) coupled with features of RV hypertrophy in FDG PET can signify RV pressure overload due to underlying pulmonary hypertension and hence observation of such findings would require careful correlation. A 46-year-old man, a coal miner for 30 years presented with the referral diagnosis of pneumoconiosis for evaluation of a suspicious appearing focal irregular nodular opacity measuring 1.3 x 0.8 cm in the right upper lobe on a CT scan of the thorax. In addition, there was evidence of advanced interstitial fibrosis with nodular perilymphaticinterstitial disease; prominent subpleural basilar abnormalities were noted which was in keeping with interstitial pneumonitis. Also reported was moderate cardiomegaly and mediastinal adenopathyespecially in the lower right paratracheal region. He was referred for FDG PET which was done to ascertain the nature of the suspicious pulmonary nodule seen on CT of the thorax. Unusually intense FDG uptake was observed in the RV along with diffuse FDG uptake in the posterior intercostal muscles. The ratio of the SUVmax of the RV (12.1) to the left ventricle (12.9) was 0.93. This signified RV pressure overload due to underlying pulmonary hypertensionproven subsequently by 2D echocardiography and arterial blood gas analysis. It is important for the PET reader to be aware of this as it can provide valuable and clinically significant information; with growing use of FDG PET, such findings are becoming increasingly evident.