F-FDG accumulation at the early onset of acute exacerbation of idiopathic interstitial pneumonia on F-FDG PET/CT: A case report.

Acute exacerbation of idiopathic interstitial pneumonias (AE-IIPs) is a disease associated with a poor prognosis in patients with IIPs. However, the specific characteristics of fluorine-18 2-fluoro-2-deoxy-d-glucose (F-FDG) positron emission tomography/computed tomography (PET/CT) imaging for AE-IIPs remain unclear. Herein, we present the case of a patient with lung cancer combined with IIPs who underwent F-FDG PET/CT at the early onset of AE-IIPs. The scan, conducted 18 days post-bronchoscopy for lung cancer evaluation, revealed AE-IIPs before the onset of respiratory failure. New ground-glass opacities appeared, accompanied by significant F-FDG accumulation extending beyond these regions. To the best of our knowledge, this report represents the first assessment of F-FDG PET/CT images at the early onset of AE-IIPs before respiratory failure in humans. The observed features in this PET image could potentially contribute to our understanding of the pathophysiology of AE-IIPs.