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A variability study of regional alveolar oxygen tension measurement in humans using hyperpolarized 3 He MRI
Author(s) -
Hamedani Hooman,
Kadlecek Stephen J.,
Ishii Masaru,
Emami Kiarash,
Kuzma Nicholas N.,
Xin Yi,
Rossman Milton,
Rizi Rahim R.
Publication year - 2013
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24604
Subject(s) - intraclass correlation , repeatability , coefficient of variation , reproducibility , nuclear medicine , correlation coefficient , magnetic resonance imaging , pulmonary function testing , medicine , lung function , nuclear magnetic resonance , chemistry , lung , mathematics , radiology , statistics , physics , chromatography
Purpose A systematic study of the short‐term and long‐term variability of regional alveolar partial pressure of oxygen tension ( p A O 2 ) measurements using 3 He magnetic resonance imaging was presented. Additionally, the repeatability of the average evaluated p A O 2 was compared with that of the standard pulmonary function tests. Methods Pulmonary function test and p A O 2 imaging were performed on 4 nonsmokers (1 M, 3 F, 56 ± 1.7 years) and 4 smokers (3 M, 1 F, 52 ± 7.5 years) during three visits over the course of 2 weeks. Two measurements were performed per visit. Variability of p A O 2 was assessed using a mixed‐effect model, with an intraclass correlation coefficient calculated for each group. The coefficient of variation of p A O 2 over the 3‐day period was also compared with the coefficient of variation of pulmonary function test results. Results Short‐term regional variability based on intraclass correlation coefficient was 0.71 for nonsmokers, and 0.63 for smokers, with long‐term variability significantly lower at 0.59 and 0.47, respectively. While the coefficient of variation of the average p A O 2 was similar to the repeatability of the diffusing capacity of CO, it was significantly higher than that of Forced Vital Capacity ( P = 0.02). Conclusion Short‐term and long‐term p A O 2 variability differences were used as an indication of true physiological changes in order to measure technical reproducibility. Smokers show higher physiologic variability and less technical reproducibility. The suggested p A O 2 ‐imaging technique showed a reasonable regional repeatability in nonsmokers as well as the ability to detect differences between the two groups with similar reproducibility and superior discriminatory ability when compared with pulmonary function tests. Magn Reson Med 70:1557–1566, 2013. © 2013 Wiley Periodicals, Inc.