title: Visualizing water clearance in the lung with MRI.
abstract: Current indirect measurements of alveolar fluid clearance (AFC) suggest that the rate of fluid clearance correlates with morbidity and mortality in patients with pulmonary edema. In a traditional AFC-measurement, fluid laced with a tracer macromolecule is instilled into the lung and thereafter repeated samples of the instilled fluid are extracted from the lung's fluid-filled airspaces. The change in concentration of the tracer molecule indicates the AFC-rate. In this work, a new MRI technique was developed to image lung water clearance by adding Gadolinium-DTPA to the instilled fluid. As fluid is absorbed by the animal, the concentration of gadolinium will increase, reducing the T(1) relaxation time. By repeatedly measuring the T(1) relaxation time, the AFC can be tracked over time with high spatial resolution. The new technique was tested both in phantoms and 10 Yorkshire piglets.
authors.affiliation: Department of Medical Imaging, The Hospital for Sick Children and The University of Toronto, 555 University Avenue, Toronto, Ontario, Canada. logi@sickkids.ca
authors.forename: Logi
authors.initials: L
authors.lastname: Vidarsson
authors.forename: Emma
authors.initials: E
authors.lastname: Helm
authors.forename: Hugh
authors.initials: H
authors.lastname: O'Brodovich
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Macgowan
mesh_terms: D000818:Animals; D003287:Contrast Media; D015633:Extravascular Lung Water / Q000502:physiology*; D019786:Gadolinium DTPA; D008279:Magnetic Resonance Imaging / Q000379:methods*; D011654:Pulmonary Edema; D013552:Swine
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA