Analysis of intrapulmonary O2concentration by MR imaging of inhaled hyperpolarized helium-3
| Autor: | Anselm Deninger, Timothy P.L. Roberts, Manfred Thelen, Ernst W. Otten, L. Lauer, Reinhard Surkau, Klaus Markstaller, Werner Heil, Balthasar Eberle, T. Grossmann, W. F. Dick, Michael Ebert, Norbert Weiler, Wolfgang Schreiber, HU Kauczor |
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| Rok vydání: | 1999 |
| Předmět: |
Swine
Physiology chemistry.chemical_element Hyperpolarized Helium 3 Helium Oxygen Isotopes Physiology (medical) Administration Inhalation Tidal Volume medicine Animals Hyperpolarization (physics) Respiratory system Lung Tidal volume medicine.diagnostic_test Inhalation business.industry Respiration Osmolar Concentration Magnetic resonance imaging Magnetic Resonance Imaging medicine.anatomical_structure chemistry Feasibility Studies Nuclear medicine business |
| Zdroj: | Journal of Applied Physiology. 87:2043-2052 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.1999.87.6.2043 |
| Popis: | Inhalation of hyperpolarized 3He allows magnetic resonance imaging (MRI) of ventilated airspaces.3He hyperpolarization decays more rapidly when interacting with paramagnetic O2. We describe a method for in vivo determination of intrapulmonary O2 concentrations ([O2]) based on MRI analysis of the fate of measured amounts of inhaled hyperpolarized3He in imaged regions of the lung. Anesthetized pigs underwent controlled normoventilation in a 1.5-T MRI unit. The inspired O2 fraction was varied to achieve different end-tidal [O2] fractions ([Formula: see text]). With the use of a specifically designed applicator,3He (100 ml, 35–45% polarized) was administered at a predefined time within single tidal volumes. During subsequent inspiratory apnea, serial two-dimensional images of airways and lungs were acquired. At least once in each animal studied, the radio-frequency excitation used for imaging was doubled at constant[Formula: see text]. Signal intensity measurements in regions of interest of the animals' lungs (volume range, 54–294 cm3), taken at two different radio-frequency excitations, permitted calculation of [O2] in these regions of interest. The [O2] fractions in the regions of interest correlated closely with[Formula: see text]( R = 0.879; P < 0.0001). O2-sensitive3He-MRI may allow noninvasive study of regional distribution of ventilation and alveolar[Formula: see text] in the lung. |
| Databáze: | OpenAIRE |
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