Feasibility, Repeatability, and Correlation to Lung Function of Phase-Resolved Functional Lung (PREFUL) MRI-derived Pulmonary Artery Pulse Wave Velocity Measurements

Background: Pulse wave velocity (PWV) in the pulmonary arteries (PA) is a marker of vascular stiffening. Currently, only phase-contrast (PC) MRI-based options exist to measure PA-PWV. Purpose: To test feasibility, repeatability, and correlation to clinical data of Phase-Resolved Functional Lung (PREFUL) MRI-based calculation of PA-PWV. Study Type: Retrospective. Subjects: 79 (26 female) healthy subjects (age range 19–78), 58 (24 female) patients with chronic obstructive pulmonary disease (COPD, age range 40–77), 60 (33 female) patients with suspected pulmonary hypertension (PH, age range 28–85). Sequence: 2D spoiled gradient echo, 1.5T. Assessment: PA-PWV was measured from PREFUL-derived cardiac cycles based on the determination of temporal and spatial distance between lung vasculature voxels using a simplified (sPWV) method and a more comprehensive (cPWV) method including more elaborate distance calculation. For 135 individuals, PC MRI-based PWV (PWV-QA) was measured. Statistical Tests: Intraclass-correlation-coefficient (ICC) and coefficient of variation (CoV) were used to test repeatability. Nonparametric tests were used to compare cohorts. Correlation of sPWV/cPWV, PWV-QA, forced expiratory volume in 1 sec (FEV<inf>1</inf>) %predicted, residual volume (RV) %predicted, age, and right heart catheterization (RHC) data were tested. Significance level α = 0.05 was used. Results: sPWV and cPWV showed no significant differences between repeated measurements (P-range 0.10–0.92). CoV was generally lower than 15%. COPD and PH patients had significantly higher sPWV and cPWV than healthy subjects. Significant correlation was found between sPWV or cPWV and FEV<inf>1</inf>%pred. (R = −0.36 and R = −0.44), but not with RHC (P-range −0.11 − 0.91) or age (P-range 0.23–0.89). Correlation to RV%pred. was significant for cPWV (R = 0.42) but not for sPWV (R = 0.34, P = 0.055). For all cohorts, sPWV and cPWV were significantly correlated with PWV-QA (R = −0.41 and R = 0.48). Data Conclusion: PREFUL-derived PWV is feasible and repeatable. PWV is increased in COPD and PH patients and correlates to airway obstruction and hyperinflation. Level of Evidence: 3. Technical Efficacy: Stage 2.