Given its greater availability and lower cost, 129Xe apparent diffusion coefficient (ADC) MRI offers an alternative to 3He ADC MRI. To demonstrate the feasibility of hyperpolarized 129Xe ADC MRI, we present results from healthy volunteers (HV), chronic obstructive pulmonary disease (COPD) subjects, and age-matched healthy controls (AMC). The mean parenchymal ADC was 0.036 ± 0.003 cm2 sec-1 for HV, 0.043 ± 0.006 cm2 sec-1 for AMC, and 0.056 ± 0.008 cm2 sec-1 for COPD subjects with emphysema. In healthy individuals, but not the COPD group, ADC decreased significantly in the anterior-posterior direction by ∼22% (P = 0.006, AMC; 0.0059, HV), likely because of gravity-induced tissue compression. The COPD group exhibited a significantly larger superior-inferior ADC reduction (∼28%) than the healthy groups (∼24%) (P = 0.00018, HV; P = 3.45 × 10-5, AMC), consistent with smoking-related tissue destruction in the superior lung. Superior-inferior gradients in healthy subjects may result from regional differences in xenon concentration. ADC was significantly correlated with pulmonary function tests (forced expiratory volume in 1 sec, r = -0.77, P = 0.0002; forced expiratory volume in 1 sec/forced vital capacity, r = -0.77, P = 0.0002; diffusing capacity of carbon monoxide in the lung/alveolar volume (VA), r = -0.77, P = 0.0002). In healthy groups, ADC increased with age by 0.0002 cm2 sec-1 year-1 (r = 0.56, P = 0.02). This study shows that 129Xe ADC MRI is clinically feasible, sufficiently sensitive to distinguish HV from subjects with emphysema, and detects age- and posture-dependent changes.
- apparent diffusion coefficient
- chronic obstructive pulmonary disease
- pulmonary function testing
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging