Fig. 4.

¹²⁹Xe ventilation images for a healthy 12-year-old boy (HV-14, top row) and an 11-year-old boy with cystic fibrosis (CF-7, bottom row). The homogeneous signal seen throughout the lungs of the healthy control indicates that all regions of the lung are well ventilated. In contrast, the hyperpolarized ¹²⁹Xe images of the child with cystic fibrosis display numerous regions of low signal intensity, indicating that ventilation is substantially impaired in multiple regions of the lungs