Automated T2* measurements using supplementary field mapping to assess cardiac iron content. Issue 2 (4th January 2013)

• Record Type: Journal Article
• Authors: Taylor, Brian A.; Loeffler, Ralf B.; Song, Ruitian; McCarville, Mary E.; Hankins, Jane S.; Hillenbrand, Claudia M.
• Is Part Of: Journal of magnetic resonance imaging. Volume 38:Issue 2(2013)
• Page Start: 441
• Page End: 447
• Publication Date: 2013-01-04
• Subjects: Magnetic resonance imaging -- Periodicals; 616
• DOI: 10.1002/jmri.23990
• Languages: English
• ISSNs: 1053-1807

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="jmri23990-sec-0001" sec-type="section"> <title>Purpose</title> <p>To develop and evaluate an algorithm that automatically identifies high‐susceptibility areas and excludes them from T<sub>2</sub>* measurements in the left ventricle (LV) for myocardial iron measurements.</p> </sec> <sec id="jmri23990-sec-0002" sec-type="section"> <title>Materials and Methods</title> <p>An autoregressive moving average (ARMA) model was implemented on multigradient echo scans of 24 patients (age range 3–45 years, 10 male/14 female). Voxels with relatively high susceptibility (>3 Hz/mm) were flagged and deselected from the T<sub>2</sub>* calculations for iron quantification. The mean, standard deviation, and coefficient of variation (CoV) of the ARMA‐defined region were compared to the CoV of four distinct regions of the LV and the entire LV using a Student's <italic>t</italic>‐test (α = 0.05).</p> </sec> <sec id="jmri23990-sec-0003" sec-type="section"> <title>Results</title> <p>The CoV of T<sub>2</sub>* values obtained by the ARMA method are comparable with that in the interventricular septum (IS), where susceptibility was the lowest (CoV = 0.31). The ARMA method provides a greater area (51.9 ± 13.7% of the LV) to measure T<sub>2</sub>* than that using the IS alone (21.1 ± 3.4%, <italic>P</italic> < 0.0001). Areas where low susceptibility are measured corroborate with areas reported in previous studies that investigated T<sub>2</sub>* variations throughout the LV.</p> </sec> <sec id="jmri23990-sec-0004" sec-type="section"> <title>Conclusion</title> <p>An automated method to measure T<sub>2</sub>* relaxation in the LV with minimal effects from susceptibility has been developed. Variability is reduced while covering more regions for cardiac T<sub>2</sub>* calculation. J. Magn. Reson. Imaging 2013;38:441–447. © 2012 Wiley Periodicals, Inc.</p> </sec> </abstract>