Exercise Induced Bronchoconstriction (0476-359)

Exercise-induced bronchoconstriction (EIB) is a condition where airways tighten when you exercise and may cause coughing, wheezing, or shortness of breath. In many patients, this condition can cause lung function to drop making it harder to breath. An instrument called a spirometer is commonly used to measure lung function. This traditional means of assessing lung function in asthma is limited in its ability to provide information as to where in the lung the tightness is. Hyperpolarized helium magnetic resonance imaging (3He MRI) is a novel way to see the where air is going in the lungs using an MRI and special gas. The ability to see where the air can and cannot reach in the lungs may help show more accurately if a medication is working to make the asthma better. The purpose of this study is to examine patients with EIB in order to see if 3He MRI provides a better way to measure lung function. Patients will be given either montelukast sodium, a drug to improve the ability to breath with EIB, or placebo and then put on a treadmill to induce an occurrence of airway constriction. The patient\'s lung function will be measured more than once using both the spirometer and the 3He MRI.