129Xe and free-breathing 1H ventilation MRI in patients with cystic fibrosis

Free-breathing ¹H MRI offers a means of producing surrogate ventilation images without use of a contrast agent but more validation against direct ventilation imaging methods such as hyperpolarised gas MRI is required. 24 patients with cystic fibrosis were scanned with ¹H and ¹²⁹Xe ventilation MRI. There were strong correlations between ¹H ventilation defect percentage (VDP), ¹²⁹Xe VDP, lung clearance index and FEV₁. ¹H VDP was typically smaller than ¹²⁹Xe VDP with wide limits of agreement (LOA) (bias 2.8%, LOA -13.7%, 19.3%). Both similarities and differences between ¹²⁹Xe and ¹H ventilation images were observed across the range of disease severity.