TY - JOUR
T1 - Quantitative assessment of regional myocardial function in a rat model of myocardial infarction using tagged MRI
AU - Thomas, D.
AU - Ferrari, V. A.
AU - Janik, M.
AU - Kim, D. H.
AU - Pickup, S.
AU - Glickson, J. D.
AU - Zhou, R.
N1 - Funding Information:
Acknowledgements This study was supported by a grant from the National Institutes of Health (EB-002473) to RZ. We thank Dr. M. Brennick for usage of his MR volume coil.
PY - 2004/12
Y1 - 2004/12
N2 - We characterized global and regional left ventricular (LV) function during post myocardium infarction (MI) remodeling in rats, which has been incompletely described by previous MRI studies. To assess regional wall motion, four groups of infarcted animals corresponding to 1-2, 3-4, 6-8 and 9-12 weeks post-MI respectively were imaged using a fast gradient echo sequence with a 2D spatial modulation of magnetization (SPAMM) tagging preparation. An additional group was serially imaged (1-2 and 6-7 weeks post-MI) to assess the global function. Regional and global functional parameters of infarcted rats were compared to non-infarcted normal rats. Compared to normal rats, a decrease in ejection fraction (70 ± 7 vs. 40 ± 8%, p < 0.05) was observed in rats with MI. Maximal and minimal principal stretches (λ1, λ2) and strains (E1, E2), principal angle (β) and displacement varied regionally in normal rats but deviated significantly from the normal values in rats with MI particularly in the infarcted and adjacent zones. Not only was strain magnitude reduced segmentally post-MI, but strain direction became more circumferentially oriented, particularly in rats with larger infarctions. We report the first regional myocardial strain values in normal and infarcted rats. These results parallel findings in humans, and provide a unique tool to examine regional mechanical influences on the remodeling process.
AB - We characterized global and regional left ventricular (LV) function during post myocardium infarction (MI) remodeling in rats, which has been incompletely described by previous MRI studies. To assess regional wall motion, four groups of infarcted animals corresponding to 1-2, 3-4, 6-8 and 9-12 weeks post-MI respectively were imaged using a fast gradient echo sequence with a 2D spatial modulation of magnetization (SPAMM) tagging preparation. An additional group was serially imaged (1-2 and 6-7 weeks post-MI) to assess the global function. Regional and global functional parameters of infarcted rats were compared to non-infarcted normal rats. Compared to normal rats, a decrease in ejection fraction (70 ± 7 vs. 40 ± 8%, p < 0.05) was observed in rats with MI. Maximal and minimal principal stretches (λ1, λ2) and strains (E1, E2), principal angle (β) and displacement varied regionally in normal rats but deviated significantly from the normal values in rats with MI particularly in the infarcted and adjacent zones. Not only was strain magnitude reduced segmentally post-MI, but strain direction became more circumferentially oriented, particularly in rats with larger infarctions. We report the first regional myocardial strain values in normal and infarcted rats. These results parallel findings in humans, and provide a unique tool to examine regional mechanical influences on the remodeling process.
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U2 - 10.1007/s10334-004-0051-y
DO - 10.1007/s10334-004-0051-y
M3 - Article
C2 - 15517473
AN - SCOPUS:14944373094
SN - 0968-5243
VL - 17
SP - 179
EP - 187
JO - Magnetic Resonance Materials in Physics, Biology, and Medicine
JF - Magnetic Resonance Materials in Physics, Biology, and Medicine
IS - 3-6
ER -