¹⁸F‐FDG accumulation at the early onset of acute exacerbation of idiopathic interstitial pneumonia on ¹⁸F‐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 ( 18 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 18 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 18 F‐FDG accumulation extending beyond these regions. To the best of our knowledge, this report represents the first assessment of 18 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.