Using Dynamic Chest Radiography to Assess the Impact of Endobronchial Valve Treatment on Lung Volumes and Diaphragm Motion in Severe Emphysema

Abstract

Introduction: Lung volume reduction (LVR) using endobronchial valves (EBV) can improve lung function in patients with emphysema, but detailed assessment can be difficult soon after EBV. Dynamic chest radiography (DCR) is a novel, real time X-ray imaging system (Konica Minolta, Inc.) with a low radiation dose compared to CT. It is performed rapidly in a standard radiology room with minimal training. Aims and Objectives: We used DCR to assess changes in lung capacity and diaphragm motion after EBV. Methods: A 76 year old woman (heterogeneous emphysema, complete fissures, previous left lower lobe EBV) (BMI 16kg/m2; FEV1 45, FVC 64, RV 270, TLCO 38 [% predicted]) was referred for right lower lobe EBV. DCR was performed immediately prior to and 48 hours post EBV: sequential PA and lateral images were recorded at 15fps over 13s during tidal and forced breathing. Lung field area per frame was recorded to calculate TLC. Diaphragm motion was tracked by software. Results: 8 EBVs were placed in the right lower lobe: volume loss was seen on CXR and DCR. Results are shown in Table 1. TLC pre-EBV calculated by DCR (7.55L) correlated with PFT TLC (7.42L). Conclusions: DCR demonstrated improvement in TLC, diaphragm motion, speed, and tidal breathing pattern 48 hours post EBV. DCR is a useful imaging modality to study diaphragm kinetics in lung volume reduction alongside PFTs and CT.