The variability of regional airflow obstruction within the lungs of patients with asthma: Assessment with hyperpolarized helium-3 magnetic resonance imaging

摘要: Background It is unknown whether focal changes of airflow obstruction within the lungs patients with asthma vary or are fixed in location time repeated bronchoconstriction. With hyperpolarized helium-3 magnetic resonance (H 3 HeMR) imaging, airspaces depicted and areas shown as "ventilation defects." Objective To investigate regional Methods H HeMR spirometry were performed before (pre) immediately after (post) methacholine challenge 10 young on 2 days that 7-476 (mean, 185.3 ± 37.2 days) apart. Pair-wise image comparisons to determine change ventilation defects lung their size. Results When comparing premethacholine versus postmethacholine post-methacholine images days, 41% 10% 69% 5% ( P = .017) defects, respectively, same location, those, 12% 43% .022), did not Comparing images, 58% 9% day 1 73% 7% .088) 2. On both days, percent increase defect number from was much greater than decrease spirometric values Conclusion Many persisted recurred bronchoconstriction, suggesting relatively lung. Clinical implications The findings give new insight into variability asthma.