Hyperpolarized Helium-3 Lung MRI Procedures
Children underwent a standard imaging protocol with safety monitoring under IND 57866. Images were obtained without sedation using a 1.5-T commercial whole-body scanner (Avanto, Siemens Medical Solutions, Malvern PA) and either a flexible, vest-shaped chest radio frequency (RF) coil (Clinical MR Solutions, Brookfield, WI) or a fixed geometry RF coil (Rapid Biomedical, Rimpar, Germany) tuned to the He-3 resonant frequency. Details of the MR acquisition procedures have been published previously 11 and are described in detail in the E-Supplement methods.