Novel Pulmonary Function Measures for Diagnosis of Bronchiolitis Obliterans Syndrome Following Hematopoietic Stem-Cell Transplantation in Children

In this study, we will study 129Xe-MRI and LCI as tools for diagnosis of BOS in pediatric patients who have received Hematopoietic Stem Cell Transplantation (HSCT) and have been identified as eligible for this study. Participants will be required to have vital signs collected, complete breathing tests and complete an MRI. The MRI will require participants to perform breath holds in the MRI scanner with xenon gas while being coached by a research assistant.