Abstract
Introduction: 18FDG PET/CT imaging may be a useful tool to study lung inflammation in COPD; however the optimal protocol for this imaging biomarker has yet to be established.
Method:We aimed to develop a combined 18FDG-PET/CT imaging protocol optimised to quantify lung inflammation. 6 patients with moderate-severe COPD underwent dynamic 18FDG-PET imaging combined with serial blood sampling (arterial and venous) to determine the localised plasma activity time curve. High resolution CT(HRCT) was utilised to segment the lung and determine areas of emphysema. 3 sets of comparative input functions were analysed (arterial, venous and image derived arterial input function). 18FDG kinetics was fitted using the Patlak method.
Results:Similar results were obtained using time activity curves from all 3 input functions. The arterial input was always found to be slightly higher than the others (Fig.1 Left). Patlak analysis of the time-activity curves for each of the CT derived lung lobes allowed generation of images of slope (influx constant Ki) and intercept (initial volume of distribution)(Fig.1 Right). Acquisition of HRCT co-registered to FDG-PET allows precise demarcation and quantification of FDG in emphysematous areas of the lung. The reproducibility of the technique is currently being studied.
Conclusion:18FDG PET/CT imaging has the potential to be a non-invasive biomarker of lung inflammation in COPD.
(Funded by Pfizer Inc.)
- © 2014 ERS