Chronic Obstructive Pulmonary Disease: Lobar Analysis with Hyperpolarized 129Xe MR Imaging

Purpose: To compare lobar ventilation and apparent diffusion coefficient (ADC) values obtained with hyperpolarized xenon 129 (Xe-129) magnetic resonance (MR) imaging to quantitative computed tomography (CT) metrics on a lobar basis and pulmonary function test (PFT) results on a whole-lung basis in patients with chronic obstructive pulmonary disease (COPD). Materials and Methods: The study was approved by the National Research Ethics Service Committee; written informed consent was obtained from all patients. Twenty-two patients with COPD (Global Initiative for Chronic Obstructive Lung Disease stage II-IV) underwent hyperpolarized Xe-129 MR imaging at 1.5 T, quantitative CT, and PFTs. Whole-lung and lobar Xe-129 MR imaging parameters were obtained by using automated segmentation of multisection hyperpolarized Xe-129 MR ventilation images and hyperpolarized Xe-129 MR diffusion-weighted images after coregistration to CT scans. Whole-lung and lobar quantitative CT-derived metrics for emphysema and bronchial wall thickness were calculated. Pearson correlation coefficients were used to evaluate the relationship between imaging measures and PFT results. Results: Percentage ventilated volume and average ADC at lobar Xe-129 MR imaging showed correlation with percentage emphysema at lobar quantitative CT (r = 20.32, P < .001 and r = 0.75, P < .0001, respectively). The average ADC at whole-lung Xe-129 MR imaging showed moderate correlation with PFT results (percentage predicted transfer factor of the lung for carbon monoxide [T-LCO]: r = -0.61, P < .005) and percentage predicted functional residual capacity (r = 0.47, P < .05). Whole-lung quantitative CT percentage emphysema also showed statistically significant correlation with percentage predicted T-LCO (r = 20.65, P < .005). Conclusion: Lobar ventilation and ADC values obtained from hyperpolarized Xe-129 MR imaging demonstrated correlation with quantitative CT percentage emphysema on a lobar basis and with PFT results on a whole-lung basis. (C) RSNA, 2016