Strain imaging using cardiac magnetic resonance

Abstract

The objective assessments of left ventricular (LV) and right ventricular (RV) ejection fractions (EFs) are the main important tasks of routine cardiovascular magnetic resonance (CMR). Over the years, CMR has emerged as the reference standard for the evaluation of biventricular morphology and function. However, changes in EF may occur in the late stages of the majority of cardiac diseases, and being a measure of global function, it has limited sensitivity for identifying regional myocardial impairment. On the other hand, current wall motion evaluation is done on a subjective basis and subjective, qualitative analysis has a substantial error rate. In an attempt to better quantify global and regional LV function; several techniques, to assess myocardial deformation, have been developed, over the past years. The aim of this review is to provide a comprehensive compendium of all the CMR techniques to assess myocardial deformation parameters as well as the application in different clinical scenarios.

Keywords: CMR tagging; Cardiovascular magnetic resonance; Feature tracking; Myocardial deformation imaging; Myocardial strain.

Fig. 1

Schematic picture representing the left ventricle (LV) and the myocardial deformation directions. L longitudinal shortening, C circumferential shortening, R radial thickening

Fig. 2

Example of coloured strain analysis with a feature-tracking software (Circle CVI42®). From long-axis four-chamber SSFP cine image (a), longitudinal strain curve is derived (b) and short-axis SSFP image (c) is used for calculation of circumferential (d) and radial strain curves (e)

Fig. 3

Example of coloured strain analysis with a feature-tracking software (Circle CVI42®) for the calculation of RV myocardial strain. a Four-chamber SSFP cine image, used to derive the RV longitudinal strain curve (b). c Short-axis SSFP cine image allows for the calculation of radial (d) and circumferential (e) RV strain curves