Figure 2:

Selected sections from representative ¹²⁹Xe ventilation and ¹H MR anatomic images in individual subjects. A, Steady-state free-precession ¹H MR images in a healthy volunteer. B, Corresponding ¹²⁹Xe ventilation MR images in the same healthy volunteer. C, Steady-state free-precession ¹H MR images in a subject with COPD. D, Corresponding ¹²⁹Xe ventilation MR images in the same subject with COPD show substantial ventilation defects and regions lacking ventilation.