The acquisition of regional cardiac function parameters nowadays encompasses several techniques. Tissue tagging and phase contrast velocity mapping (also called tissue phase mapping, TPM) were already introduced in the 80ies, more recently displacement encoding with stimulated echoes (DENSE) and strain encoding (SENC) have been proposed.

Tagging uses a preparation module where a grid of magnetic saturation bands (tags) is superimposed on the myocardium at the early systole followed by an imaging period showing the tag deformation throughout the cardiac cycle. An advantage of tagging is given by the quick visual inspection it allows for. The quantitative analysis of the tag deformation is rather complicated and can require time-consuming postprocessing, although the recently proposed harmonic phase (HARP) analysis techniques has significantly speeded up this process.

The DENSE technique encodes in-plane or through-plane tissue displacement directly in the signal phase. Because of T1 relaxation, like tagging, the signal carrying the displacement encoding decays over the cardiac cycle. On the other hand, the postprocessing has the advantage of being very simple and quick. DENSE is not yet widely available on clinical scanners.

In SENC tag planes oriented parallel to the imaging plane (unlike tagging) are used. Therefore, through-plane strain is directly related to the pixel intensity, and only little postprocessing is needed. As in tagging, the tags still fade over the cardiac cycle due to T1 relaxation. Longitudinal strain can be determined from short-axis views, circumferential strain from a long-axis plane, radial strain cannot be measured.

The TPM method directly measures the myocardial velocities in all spatial dimensions using the phase contrast technique. The sequence is widely available, but although postprocessing is rather quick straightforward, dedicated software is necessary which is not widely available. Even though single slice measurements if three short axis planes are typically performed also 3D measurements have been presented.

Numerous studies have been performed on volunteers, age and gender differences, patient (ischemic heart disease, RV function, cardiomyopathies, coronary artery bypass graft, heart transplantation), as well as on animals including dogs, rats, mice, and rabbits.

Both quantities that are measured by the different methods, i.e. tissue velocities and displacement, can be transformed into each other with some error propagation in both ways. However, Tissue Velocity Mapping data has been used to calculate strain and strain rate revealing an excellent agreement with strain derived from contour tracking of SSFP Cine images and with a numerical phantom with known strain rate.

The most recent approach to determine strain values uses feature tracking based on SSFP Cine images as acquired routinely for myocardial function parameters. This is done in accordance to speckle tracking echocardiography that analyzes tissue motion using natural patterns on ultrasonic images. Recently, the correlation between strain based on MR feature tracking and speckle tracking echocardiography has been published.