Quantification of regional contractile function after infarction: strain analysis superior to wall thickening analysis in discriminating infarct from remote myocardium
Marco J. W. Götte, MD* d,
Albert C. van Rossum, MD, PhD* d,
Jos W. R. Twisk, PhD d,
Joost P. A. Kuijer, MSc d,
J. Tim Marcus, PhD d and
Cees A. Visser, MD, PhD* d
* Department of Cardiology, University Hospital ("Vrije Universiteit"), Amsterdam, The Netherlands
EMGO Institute, University Hospital ("Vrije Universiteit"), Amsterdam, The Netherlands
Department of Clinical Physics and Informatics, University Hospital ("Vrije Universiteit"), Amsterdam, The Netherlands
d Institute for Cardiovascular Research, Amsterdam, The Netherlands

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Figure 1 Calculation of two-dimensional WT and strain on short-axis cine MR images (A) and tagged images (B), respectively. The end-diastolic images are shown on the left and the end-systolic images on the right. For calculation of WT, the centerline method was used. The white arrow (a) is one of the 100 chords, representing the end-diastolic WT. The other white arrow (a') represents the end-systolic WT at that point. According the formula (a' a) x 100/a, the percent change in WT between end-diastole and end-systole can be calculated. On the tagged images, the white diamonds indicate the intersection points of the tagging grid. By using groups of three intersection points, multiple triangular elements of the myocardium can be created (C). The variables r and c both represent a line segment in the undeformed state, in the radial and circumferential directions, respectively. The variables r' and c' represent the same line segment in the deformed state. (For the two-dimensional strain computation of a triangle, see Appendix.) MR = magnetic resonance; WT = wall thickness.
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Figure 2 Schematic definition of circumferential segments at the basal level (top), mid-ventricular level (middle) and apical level (bottom). The perfusion territory of the LAD was considered to be at the basal level in segments 10 to 3, at the mid level in segments 9 to 3 and at the apical level in segments 9 to 4. The infarct-related area is indicated by the dashed segments, the adjacent area by the solid segments and the remote area by the open segments. LAD = left anterior descending coronary artery.
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Figure 3 Contractile function in patients with MI in the infarct-related and remote myocardium, as quantified by WTh analysis and strain analysis. Strain analysis revealed significant differences in contractile function between infarct-related and remote myocardium, whereas WTh did not. r = radial stretch; MI = myocardial infarction; WTh = wall thickening.
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