Yanping Sun1, Terence Tan1, Sanaz Zhalehdoust-Sani2, Yang-Sheng Tzeng3, Ken Lutchen2, Mitchell S. Albert1
1Radiology, University of Massachusetts Medical School, Worcester, MA, USA; 2Biomedical Engineering, Boston University, Boston, MA, USA; 3Radiology, Brigham and Women's Hospital, Boston, MA, USA
To assess the chronic respiratory impairment in asthmatics, we performed hyperpolarized 3He MRI to image the change in ventilation distribution in asthmatic and healthy subjects at baseline, after methacholine (Mch) challenge, after deep inspirations (DI) following Mch challenge, and after Albuterol administration. The asthmatic groups showed significantly higher defect volumes and heterogeneity at baseline than healthy subjects, which was further exacerbated by Mch challenge. Unlike in healthy subjects, DIs appeared to have little impact on diminishing defect volumes and heterogeneity in the asthmatic lung. Albuterol reversed ventilation defects and heterogeneity in healthy subjects less so in severe asthmatics.