Three-dimensional systolic strain patterns in the normal human left ventricle: characterization with tagged MR
C C Moore1, C H Lugo-Olivieri, E R McVeigh
1Departments of Radiology and Biomedical Engineering, the Johns Hopkins University School of Medicine, 600 N Wolfe St, Baltimore, MD 21287, USA.
Purpose:
To present a database of systolic three-dimensional (3D) strain evolution throughout the normal left ventricle (LV) in humans.
Materials And Methods:
In 31 healthy volunteers, magnetic resonance (MR) tissue tagging and breath-hold MR imaging were used to generate and then detect the motion of transient fiducial markers (ie, tags) in the heart every 32 msec. Strain and motion were calculated from a 3D displacement field that was fit to the tag data. Special indexes of contraction and thickening that were based on multiple strain components also were evaluated.
Results:
The temporal evolution of local strains was linear during the first half of systole. The peak shortening and thickening strain components were typically greatest in the anterolateral wall, increased toward the apex, and increased toward the endocardium. Shears and displacements were more spatially variable. The two specialized indexes of contraction and thickening had higher measurement precision and tighter normal ranges than did the traditional strain components.
Conclusion:
In this study, the authors noninvasively characterized the normal systolic ranges of 3D displacement and strain evolution throughout the human LV. Comparison against this multidimensional database may permit sensitive detection of systolic LV dysfunction.
