MRI myocardial motion and fiber tracking: a confirmation of knowledge from different imaging modalities.

OBJECTIVE

A helical configuration underlies the anatomy of cardiac structure, and a structure/function relationship is needed to determine if the ventricular myocardial band model defines this spatial relationship. This report explores how studies of velocity-encoded phase contrast magnetic resonance imaging (MRI) for myocardial motion and fiber tracking algorithms that imply fiber orientations can (a) quantify regional myocardial wall motion of the entire heart, (b) determine if these motion of implied fiber orientation link with the helical heart model, and (c) reveal if this new knowledge correlates with imaging information from other different imaging modalities.

METHODS

Accumulated left ventricular motion patterns that accurately differentiate radial (i.e. contraction and expansion), rotational (i.e. twisting and untwisting), and longitudinal (i.e. lengthening and shortening) motion components are correlated with structure/function data achieved by sonomicrometer crystals, echocardiography, corrosion casts, and MUGA recordings.

RESULTS

Acceleration fiber tracking to determine fiber orientation and cardiac motion during the ejection and rapid filling phases of the cardiac cycle corresponded to maximal force displayed by ultrasonic crystals placed into the angulation of the presumed functional units of the descending and ascending segments of the apical loop of the helical ventricular myocardial band, and motion by echocardiographic recordings. These integrated findings imply a favourable interaction of MRI with the myocyte orientation of the helical ventricular myocardial band.

CONCLUSIONS

These composite findings indicate that phase contrast MRI techniques for high temporal resolution velocity mapping during cardiac motion and myocardial fiber tracking confirm other technologies, and centralize the capacity of MRI to link other imaging methods together relative to a single helical structural model. The close agreement amongst a spectrum of imaging studies provide a very powerful integration that transcends a single look; the same thing is observed by each component of global technology, thereby implying that the helical ventricular band is the structural basis for these functional changes.