Improved efficiency and quantitative accuracy in hyperpolarized 129Xe ventilation imaging using 2D spiral acquisition

Despite yielding high signal-to-noise ratio, conventional gradient recalled echo (GRE) sequence requires a relatively long breath-hold for 129Xe ventilation imaging. 2D-spiral sequence enables faster imaging and offers possibility to correct regional B1/flip-angle inhomogeneities and signal decay using keyhole reconstruction without making assumptions about bias texture that can obscure the physiology of interest. Here, GRE and 2D-spiral showed comparable image quality and revealed regional ventilation impairment in cystic fibrosis. Furthermore, flip-angle correction preserved signal variation due to underlying lung pathophysiology, including gravitation ventilation gradients and subtle defects. Thus, flip-angle corrections in 2D-spiral sequence may detect early and reversible disease-induced ventilation impairment.