Systemic sclerosis (SSc) is a complex connective tissue disorder. Two-thirds die within 10 years from interstitial lung disease (ILD) and pulmonary hypertension. The pathogenesis is incompletely understood, but TGF-beta activation mediated by integrins is a putative common pathway. There is no effective method for the detection of TGF-beta activation in situ. There is a pressing need to identify non-invasive biomarkers of lung fibrogenesis. 18F-fluciclatide is a highly selective ligand for the avb3 and avb5 integrin receptors. We propose a pilot study to determine the utility of 18F-fluciclatide-PET in assessing fibrogenesis in SSc-ILD. We will correlate the tracer uptake with volumetric CT and CT pulmonary perfusion as imaging markers of pulmonary fibrosis and microvascular changes. If validated, this technique will be employed to assess drug efficacy and disease progression in SSc.