Areas of normal pulmonary parenchyma on HRCT exhibit increased FDG PET signal in IPF patients

Abstract

PurposePatients with idiopathic pulmonary fibrosis (IPF) show increased PET signal at sites of morphological abnormality on high-resolution computed tomography (HRCT). The purpose of this investigation was to investigate the PET signal at sites of normal-appearing lung on HRCT in IPF.MethodsConsecutive IPF patients (22 men, 3 women) were prospectively recruited. The patients underwent 18F-FDG PET/HRCT. The pulmonary imaging findings in the IPF patients were compared to the findings in a control population. Pulmonary uptake of 18F-FDG (mean SUV) was quantified at sites of morphologically normal parenchyma on HRCT. SUVs were also corrected for tissue fraction (TF). The mean SUV in IPF patients was compared with that in 25 controls (patients with lymphoma in remission or suspected paraneoplastic syndrome with normal PET/CT appearances).ResultsThe pulmonary SUV (mean ± SD) uncorrected for TF in the controls was 0.48 ± 0.14 and 0.78 ± 0.24 taken from normal lung regions in IPF patients (p < 0.001). The TF-corrected mean SUV in the controls was 2.24 ± 0.29 and 3.24 ± 0.84 in IPF patients (p < 0.001).ConclusionIPF patients have increased pulmonary uptake of 18F-FDG on PET in areas of lung with a normal morphological appearance on HRCT. This may have implications for determining disease mechanisms and treatment monitoring.

18F-FDG Uptake in Less Affected Lung Field Provides Prognostic Stratification in Patients with Interstitial Lung Disease

“…In addition, increased 18 F-FDG uptake in areas of apparently normal pulmonary parenchyma on HRCT was observed in patients with IPF (16). This finding suggested that higher 18 F-FDG uptake by less-affected lung tissue may provide additional clinical information in patients with ILD, in addition to the morphologic changes observed by HRCT.…”

“…SUV mean was measured in 1 target volume of interest (VOI), which was placed at the most normalappearing area in the lungs of each subject. The target VOIs had a fixed spheric shape measuring 18 cm 3 (16). The area occupied by the VOI typically shows no or minimal signs of increased attenuation on CT (Fig.…”

Quantification of Lung PET Images: Challenges and Opportunities

“…Inflammation characterizes several lung diseases, including pneumonia, cystic fibrosis, chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS), asthma, and interstitial lung diseases such as idiopathic pulmonary fibrosis (IPF), among others (7,8,10,11,(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25). Because ARDS, COPD, and IPF can cause significant variability in the amounts of air, blood, and water in the lungs (Fig.…”

Glucose Transporter 1–Dependent Glycolysis Is Increased during Aging-Related Lung Fibrosis, and Phloretin Inhibits Lung Fibrosis

“…Glycolytic reprogramming has been shown to play an important role in the pathogenesis of lung fibrosis (7). Recent studies have reported that patients with IPF exhibit higher glycolytic activity in fibrotic areas, with positive retention index values being a strong predictor of deterioration in pulmonary function and of higher mortality (8,9).…”