Abstract #1663

Shah N, Washko G, Israel E, Gereige J, Mansour J, Lutchen K, Albert M, Tzeng Y

In an attempt to characterize ventilation heterogeneity, average local coefficient-of-variation and standard deviation of pixel intensity have been computed for hyperpolarized 3He MR images obtained during static ventilation. The images were acquired from asthmatics and non-asthmatics, before methacholine challenge, after methacholine challenge, and after deep inspirations. Statistically significant changes in these indices from one phase to another, as well as differences between the two subject populations, corroborate current understanding of asthmatic hyper-reactivity, and the inability of deep inspirations to reverse asthmatic bronchoconstriction.