Purpose: To quantitatively compare dynamic 19F and single breath hyperpolarized 129Xe MRI for the detection of ventilation abnormalities in subjects with mild cystic fibrosis (CF) lung disease. Methods: Ten participants with stable CF and a baseline FEV1 > 70% completed a single imaging session where dynamic 19F and single breath 129Xe lung ventilation images were acquired on a 3T MRI scanner. Ventilation defect percentages (VDP) values between 19F early-breath, 19F maximum-ventilation, 129Xe low-resolution, and 129Xe high-resolution images were compared. Dynamic 19F images were used to determine gas wash-in/out rates in regions of ventilation congruency and mismatch between 129Xe and 19F. Results: VDP values from high-resolution 129Xe images were greater than from low-resolution images (P =.001), although these values were significantly correlated (r = 0.68, P =.03). Early-breath 19F VDP and max-vent 19F VDP also showed significant correlation (r = 0.75, P =.012), with early-breath 19F VDP values being significantly greater (P <.001). No correlation in VDP values were detected between either 19F method or high-res 129Xe images. In addition, the location and volume of ventilation defects were often different when comparing 129Xe and 19F images from the same subject. Areas of ventilation congruence displayed the expected ventilation kinetics, while areas of ventilation mismatch displayed abnormally slow gas wash-in and wash-out. Conclusion: In CF subjects, ventilation abnormalities are identified by both 19F and HP 129Xe imaging. However, these ventilation abnormalities are not entirely congruent. 19F and HP 129Xe imaging provide complementary information that enable differentiation of normally ventilated, slowly ventilated, and non-ventilated regions in the lungs
