Oblique 3D MRI tags for the estimation of true 3D cardiac motion parameters

Abstract

Aim of this study is to demonstrate the advantages of oblique 3D tags in cardiac magnetic resonance imaging (MRI) and the potential to accurately describe the complex motion of the myocardial wall. 3D cardiac Cine data were densely tagged with 3D oblique tags. The latter were tracked using Gabor analysis and active geometries. From the tag intersections, common 2D parameters such as long axis shortening, radial shortening and rotation were evaluated on a global as well as detailed local level. Finally, the same data were used to estimate left ventricular volume change and myocardial stress/strain. We have successfully tracked dense 3D tags and evaluated common parameters on a detailed local level. In addition, inherently 3D parameters could be estimated. Global motion data are in accordance with previously published data. Oblique tags allow for unambiguous localization of the tag plane in all MRI slices and in any time frame. In contrast to HARP, our tag tracking methodology allows for tracking of the tags even when they are dense. Motion parameters can be extracted in greater detail. Moreover, the intersections of dense oblique 3D tags provide a natural basis for a finite element model of the heart. Straight forward access to the 3D characteristics of the cardiac motion is provided.

A Validation of Two-Dimensional In Vivo Regional Strain Computed from Displacement Encoding with Stimulated Echoes (DENSE), in Reference to Tagged Magnetic Resonance Imaging and Studies in Repeatability

“…A third limitation was obtaining 2D strain from short-axis slices when regional heart function occurs naturally in 3D. 28,38,45 Ideally, any imaging technique used and subsequent strain computations should correct for tissue through-plane motion and 2D analysis inherently bypasses denser strain computation that is possible only within a 3D continuum.…”

Heterogeneous Distribution of Left Ventricular Contractile Injury in Chronic Aortic Insufficiency

“…Although 3D displacements were measured, only two of the six strain components (circumferential and longitudinal strain) were used in our multiparametric analysis, which was due to limited-displacement measurement in the radial direction. Recent advanced MRI methods to estimate strain in the human heart, such as 3D harmonic phase [30], 3D oblique tag lines [31], and 3D displacement encoding with stimulated echoes [32], may provide higher resolution of 3D displacement measurements within a reasonable scan time for patients. A higher density of accurate displacement data may improve the estimation of all six components of strain and allow for more sensitive comparisons.…”

Cardiovascular imaging 2010 in the International Journal of Cardiovascular Imaging

“…The use of oblique 3D MRI tags was proposed by Shimuzu et al [51]. The advantage of their technique is that it permits the tracking of tags even when they are dense to allow for estimation of 3D cardiac motion parameters.…”