MODEL-FREE RECONSTRUCTION OF 3-DIMENSIONAL MYOCARDIAL STRAIN FROM PLANAR TAGGED MR-IMAGES

A technique Is presented for reconstructing a three-dimensional myocar dial strain map from a set of parallel-tagged MR images, Radial strain s were reconstructed from in vivo data from an anaesthetized dog with values between .05 and .1 with a precision of +/- .003 for a tag detec tion accuracy of .1 mm and a tag spacing of 2.5 mm, The reconstruction spatial resolution was demonstrated by reconstructing a localized dis placement abnormality. In the circumferential direction, the abnormali ty that resulted in 50% displacement attenuation had a full width at h alf maximum of 5.4 +/- .4 mm (mean +/- SD), Graphs are presented showi ng the relationship between the size of an abnormality and the ability of the method to reconstruct that abnormality. The combination of hig h resolution parallel-tagged MR images and the model-free, coordinate system-free strain reconstruction technique presented in this paper is capable of producing accurate, high resolution strain maps of the myo cardium.