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Liver and heart MR relaxometry in iron loading: Reproducibility of three methods
Author(s) -
Ferguson Mark R.,
Otto Randolph K.,
Bender Michael A.,
Kolokythas Orpheus,
Friedman Seth D.
Publication year - 2013
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.23937
Subject(s) - reproducibility , coefficient of variation , relaxometry , pixel , magnetic resonance imaging , percentile , medicine , nuclear medicine , radiology , mathematics , biomedical engineering , statistics , computer science , spin echo , artificial intelligence
Purpose To compare the derived T2* values and reproducibility of three methods used to assess iron‐loading in heart and liver. Materials and Methods In 23 pediatric patients, liver and cardiac gradient‐echo imaging datasets (within‐exam repeated sequence pairs) were evaluated. Data analyses compared derived relaxation values (average of pairs) and coefficient of variation (reproducibility of pairs). Results T2* values showed differences across methods, with pixel‐wise mean > average fit > pixel‐wise median. Coefficient of variation was found to be lower (better) with pixel‐wise median and average fit methods compared to the pixel‐wise mean technique. Maximum coefficient of variation values were lowest for the pixel‐wise median approach in both the heart and liver. Conclusion Differences in derived T2* values between methods must be considered when comparing values to established magnetic resonance imaging (MRI)‐biopsy formulas. The pixel‐wise median and average fit methods demonstrate substantial benefits in reproducibility compared to the pixel‐wise mean method. Since minimal variation in measurement is critical for patient care, median processing of relaxometry data may be preferable in both tissue types. J. Magn. Reson. Imaging 2013;38:987–990. © 2012 Wiley Periodicals, Inc.