Noninvasive quantification of left ventricular rotational deformation in normal humans using magnetic resonance imaging myocardial tagging.

摘要: It has been postulated that rotation of the left ventricular apex with respect to base is a component normal systolic function in humans, but it difficult measure noninvasively. Tagging new magnetic resonance imaging technique labels specific areas myocardium by selective radio-frequency excitation narrow planes orthogonal plane before acquiring an image. Tags appear as black lines and persist for 400-500 msec and, if applied at end diastole, will move through systole. was used noninvasively quantify torsion circumferential-longitudinal shear (shearCL) humans. Eight volunteers, aged 24-38 years, were imaged 0.38-T iron-core resistive magnet. Five short-axis images, positioned encompass entire ventricle (LV), obtained separately Four equiangular radial tags had intersecting eight locations. We calculated difference angular displacement each epicardial endocardial tag point (a being where crossed epicardium or endocardium) systole from position corresponding on basal plane. This value called angle. From this, shearCL, angle inscribed surface between position, its projection onto slice interest could be 32 points wall.(ABSTRACT TRUNCATED AT 250 WORDS)