title: Quantitative measurement of regional lung ventilation using 3He MRI.
abstract: A new strategy for a quantitative measurement of regional pulmonary ventilation using hyperpolarized helium-3 (3He) MRI has been developed. The method employs the build-up of the signal intensity after a variable number of (3)He breaths. A mathematical model of the signal dynamics is presented, from which the local ventilation, defined as the fraction of gas exchanged per breath within a given volume, is calculated. The model was used to create ventilation maps of coronal slices of guinea pig lungs. Ventilation values very close to 1 were found in the trachea and the major airways. In the lung parenchyma, regions adjacent to the hilum showed values of 0.6-0.8, whereas 0.2-0.4 was measured in peripheral regions. Monte Carlo simulations were used to investigate the accuracy of the method and its limitations. The simulations revealed that, at presently attainable signal-to-noise ratios, the ventilation parameter can be determined with a relative uncertainty of <5% over a wide range of values.
authors.affiliation: Amersham Health R&D, Medeon, SE - 205 12 Malmö, Sweden.
authors.forename: Anselm J
authors.initials: AJ
authors.lastname: Deninger
authors.forename: Sven
authors.initials: S
authors.lastname: Månsson
authors.forename: J Stefan
authors.initials: JS
authors.lastname: Petersson
authors.forename: Göran
authors.initials: G
authors.lastname: Pettersson
authors.forename: Peter
authors.initials: P
authors.lastname: Magnusson
authors.forename: Jonas
authors.initials: J
authors.lastname: Svensson
authors.forename: Björn
authors.initials: B
authors.lastname: Fridlund
authors.forename: Georg
authors.initials: G
authors.lastname: Hansson
authors.forename: Ingrid
authors.initials: I
authors.lastname: Erjefeldt
authors.forename: Per
authors.initials: P
authors.lastname: Wollmer
authors.forename: Klaes
authors.initials: K
authors.lastname: Golman
mesh_terms: D000818:Animals; D006168:Guinea Pigs; D006371:Helium; D007091:Image Processing, Computer-Assisted; D007554:Isotopes; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011659:Pulmonary Gas Exchange; D012123:Pulmonary Ventilation / Q000502:physiology; D012680:Sensitivity and Specificity
chemical_list: D007554:Isotopes; D006371:Helium