Xenon ventilation MRI in difficult asthma: initial experience in a clinical setting oleh Grace T. Mussell, Helen Marshall, Laurie J. Smith, Alberto M. Biancardi, Paul J.C. Hughes, David J. Capener, Jody Bray, Andrew J. Swift, Smitha Rajaram, Alison M. Condliffe, Guilhem J. Collier, Chris S. Johns, Nick D. Weatherley, Jim M. Wild, Ian Sabroe