| Autor: |
Ingrid Erjefeldt, Jonas Svensson, Göran Pettersson, Peter Magnusson, Klaes Golman, Georg Hansson, Per Wollmer, J. Stefan Petersson, Anselm J. Deninger, Sven Månsson, Björn Fridlund |
| Rok vydání: |
2002 |
| Předmět: |
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| Zdroj: |
Magnetic Resonance in Medicine. 48:223-232 |
| ISSN: |
0740-3194 |
| DOI: |
10.1002/mrm.10206 |
| Popis: |
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 3He 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 |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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