Abstract
Purpose To develop and evaluate an algorithm that automatically identifies high-susceptibility areas and excludes them from T2* measurements in the left ventricle (LV) for myocardial iron measurements. Materials and Methods 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 T2* 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 t-test (α = 0.05). Results The CoV of T2* 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 T2* than that using the IS alone (21.1 ± 3.4%, P < 0.0001). Areas where low susceptibility are measured corroborate with areas reported in previous studies that investigated T 2* variations throughout the LV. Conclusion An automated method to measure T2* relaxation in the LV with minimal effects from susceptibility has been developed. Variability is reduced while covering more regions for cardiac T2* calculation. © 2012 Wiley Periodicals, Inc.
Original language | English (US) |
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Pages (from-to) | 441-447 |
Number of pages | 7 |
Journal | Journal of Magnetic Resonance Imaging |
Volume | 38 |
Issue number | 2 |
DOIs | |
State | Published - Aug 2013 |
Externally published | Yes |
Keywords
- T
- autoregressive moving average (ARMA) modeling
- cardiac MR
- iron overload
- mapping
- multigradient echo (mGRE)
- susceptibility
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging