title: A method for mapping regional oxygen and CO2 transfer in the lung.
abstract: This paper presents a novel approach to visualizing regional lung function, through quantitative three-dimensional maps of O2 and CO2 transfer rates. These maps describe the contribution of anatomical regions to overall gas exchange and demonstrate how transfer rates of the two gas species' differ regionally. An algorithm for generating such maps is presented, and for illustration, regional gas transfer maps were generated using values of ventilation and perfusion imaged by PET/CT for a healthy subject and an asthmatic patient after bronchoprovocation. In a sensitivity analysis, compartment values of gas transfer showed minor sensitivity to imaging noise in the ventilation and perfusion data, and moderate sensitivity to estimation errors in global lung input values, chiefly global alveolar ventilation, followed by cardiac output and arterial-venous O2 content difference. Gas transfer maps offer an intuitive display of physiologically relevant lung function at a regional level, the potential for an improved understanding of pulmonary gas exchange in health and disease, and potentially a presurgical evaluation tool.
authors.affiliation: Department of Respiratory Diseases, Aarhus University Hospital, Noerrebrogade 44, 8000 Aarhus C, Denmark; Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA. Electronic address: troels.johansen@clin.au.dk.
authors.forename: Troels
authors.initials: T
authors.lastname: Johansen
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA.
authors.forename: Tilo
authors.initials: T
authors.lastname: Winkler
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA.
authors.forename: Vanessa Jane
authors.initials: VJ
authors.lastname: Kelly
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA; Department of Informatics, Technical University of Munich, Boltzmannstr. 3, 85748 Garching bei München, Germany.
authors.forename: Juan Sebastian
authors.initials: JS
authors.lastname: Osorio-Valencia
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA; Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Room 3-173, Cambridge, MA 02139, USA.
authors.forename: Elliot Eliyahu
authors.initials: EE
authors.lastname: Greenblatt
authors.affiliation: Department of Medicine, Pulmonary and Critical Care Unit, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA.
authors.forename: Robert Scott
authors.initials: RS
authors.lastname: Harris
authors.affiliation: Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA.
authors.forename: Jose Gabriel
authors.initials: JG
authors.lastname: Venegas
mesh_terms: D000328:Adult; D000465:Algorithms; D001249:Asthma / Q000000981:diagnostic imaging / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D064847:Multimodal Imaging / Q000379:methods; D010100:Oxygen / Q000378:metabolism*; D055420:Perfusion Imaging / Q000379:methods; D049268:Positron-Emission Tomography / Q000379:methods*; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D015203:Reproducibility of Results; D012119:Respiration; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen
keywords: Asthma; CO(2) elimination; Lung imaging; O(2) uptake; Pulmonary gas exchange; Ventilation/perfusion