Stanley John Kruger1, David Niles1, Grace Parraga2, Sean Fain1, Bernard Dardzinski3, Marcella Ruddy3, Amy Harman3, Stephen Choy2, Scott Nagle4, Christopher Francois4, David G. McCormack2, Nizar Jarjour5
1Medical Physics, University of Wisconsin, Madison, WI, United States; 2Robarts Imaging Institution, University of Western Ontario, London, ON, Canada; 3Merck Research Labs, West Point, PA, United States; 4Radiology, University of Wisconsin, Madison, WI, United States; 5Medicine & Public Health, University of Wisconsin, Madison, WI, United States
A double blind therapy trial using He-3 MRI was conducted to evaluate efficacy for exercise induced bronchoconstriction (EIB) using images of ventilation. To track regional changes in defect volume as an endpoint for treatment effect, He-3 MRI was performed at three separate visits at baseline, exercise challenge and 45 min. after challenge in 13 subjects with EIB. Drug was given at 1 of the visits, and placebo at the remaining visits. Results show decreases in ventilation volume at exercise challenge compared to baseline, with treatment reducing this effect. Both decrease in ventilation volume and treatment effect showed preferential regional behavior.