  A SPAMM tagged MRI methodology is presented allowing continuous (3.3-3.6 Hz)
sampling of 3D dynamic soft tissue deformation using non-segmented 3D
acquisitions. The 3D deformation is reconstructed by the combination of 3
mutually orthogonal tagging directions, thus requiring only 3 repeated motion
cycles. In addition a fully automatic post-processing framework is presented
employing Gabor scale-space and filter-bank analysis for tag extrema
segmentation and triangulated surface fitting aided by Gabor filter bank
derived surface normals. Deformation is derived following tracking of tag
surface triplet triangle intersections. The dynamic deformation measurements
were validated using indentation tests (~20 mm deep at 12 mm/s) on a silicone
gel soft tissue phantom containing contrasting markers which provide a
reference measure of deformation. In addition, the techniques were evaluated
in-vivo for dynamic skeletal muscle tissue deformation measurement during
indentation of the biceps region of the upper arm in a volunteer.
