Premium
Harmonic phase MR tagging for direct quantification of lagrangian strain in rat hearts after myocardial infarction
Author(s) -
Liu Wei,
Chen Junjie,
Ji Songbai,
Allen J. Stacy,
Bayly Philip V.,
Wickline Samuel A.,
Yu Xin
Publication year - 2004
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.20276
Subject(s) - harp , strain (injury) , homogeneous , lagrangian , myocardial infarction , biomedical engineering , nuclear magnetic resonance , physics , mathematics , anatomy , medicine , cardiology , mathematical analysis , quantum mechanics , thermodynamics
The utility of harmonic phase (HARP) analysis was recently demonstrated in humans and large animals as a technique for rapid and automatic analysis of tagged magnetic resonance images. In the current study, the applicability and accuracy of HARP analysis for automatic strain quantification in small animals were investigated. A validation study was performed on seven postinfarct rats and seven age‐matched controls. A method for direct computation of 2D Lagrangian strain fields from spatial derivatives of HARP images was also developed in this paper. The results of HARP analysis were evaluated by comparison with those of homogeneous strain analysis employing finite element method and manual tag tracking. Both methods were validated with simulated digital images. Compared to conventional homogeneous strain analysis, HARP analysis yielded similar results in the assessment of regional strain patterns in both control and infarct rats. Both methods detected a reduction in maximal stretch and shortening in infarct rats. Our results suggest that HARP analysis can also be applied to quantify alterations in regional myocardial wall motion in small animals. Magn Reson Med 52:1282–1290, 2004. © 2004 Wiley‐Liss, Inc.