Idiopathic Pulmonary Fibrosis: Evaluation with Positron Emission Tomography

BACKGROUND: The pathogenesis of interstitial lung disease remains under investigation, but may be related to increased inflammatory or cellular activity. This activity may be detectable with physiologic imaging. OBJECTIVES: We investigated the role of physiologic imaging using (18)F-2-fluoro-2-deoxy-D-glucose ((18)FDG)-positron emission tomography (PET) scans in idiopathic pulmonary fibrosis (IPF). METHODS: Seven male patients with histologically confirmed IPF underwent (18)FDG-PET scans. Scans were analyzed qualitatively and interpreted as positive or negative. Patients also underwent pulmonary function tests and computed tomography (CT) scans. RESULTS: The average total lung capacity was 71 +/- 22% predicted (mean +/- SD) and diffusing capacity for carbon monoxide was 44 +/- 14% predicted. All had changes consistent with IPF on chest CT and 2 patients had ground glass attenuation. Six of seven patients (86%) had a positive (18)FDG-PET scan. Changes in the (18)FDG-PET scan were seen in 1 patient corresponding to changes in clinical status. CONCLUSIONS: Our findings suggest that (18)FDG-PET scans may be helpful in the evaluation of IPF. Increased activity suggests active disease and changes in response to therapy.