Dynamic Xenon-Enhanced Spectral CT Imaging to Evaluate Regional Lung Function in an In Vivo Rabbit Model

Background/Objectives: Pulmonary diseases exhibit spatially heterogeneous functional and structural abnormalities that are inadequately represented by conventional lung function testing. This pilot study investigates dynamic xenon-enhanced dual-energy CT (Xe-DECT) for a multiparametric assessment of lung ventilation and tissue.

Methods

Four mechanically ventilated rabbits were scanned during washout of 70% xenon in oxygen using multibreath imaging with a clinical DECT both before (baseline) and after methacholine administration (post-MCh). Tracheal Xe concentration (CXe) and flow were monitored using mass spectrometry and pneumotachometry to estimate specific ventilation (sV˙ms) and end-expiratory lung volume (EELVms). DECT-derived xenon concentration and tissue density images (mg/mL) were obtained by material decomposition, yielding sV˙DECT and EELVDECT, respectively. Agreement with mass spectrometry and differences between baseline and post-MCh were assessed.