18F-fluorodeoxyglucose positron-emission tomography/CT and lung involvement in systemic sclerosis.

Systemic sclerosis (SSc) early lung involvement (interstitial lung disease (ILD)) is characterised by ground glass opacities (GGO) at high-resolution CT (HRCT).1 2 The literature provides conflicting interpretations of GGO’s clinical significance,3–5 and whether it represents inflammation or early fibrotic changes is a dilemma. In fact, HRCT cannot discriminate between ‘active inflammatory’ and ‘established fibrotic’ GGO.6 Instead, 18-F fluoro-deoxy-d-glucose positron-emission tomography/CT (18F-FDG-PET/CT) locates areas of increased metabolic activity,7 8 but no data on the ‘established fibrotic’ GGO metabolic activity has been demonstrated yet. We aimed at evaluating if 18F-FDG-PET/CT scan may identify GGO inflammatory component in SSc-ILD.9Seven patients with SSc (six females; mean age 59.56±9.15 years, median disease duration 5 years) from the Rheumatology Outpatient Clinic, University of Florence underwent a 18F-FDG-PET/CT to rule out the presence of a neoplasia for a lung nodule detected at chest HRCT. HRCT pulmonary segments were classified as ‘negative’ (normal morphology) and ‘positive’ (presence of GGO), and the Warrick score was used to quantify ILD at HRCT.10 18F-FDG-PET/CT images were retrospectively …