Abstract
A multiplanar Dynamic Magnetic Resonance Imaging (MRI)
technique that extends our earlier work on single-plane Dynamic
MRI is described. Scanned images acquired while an utterance
is repeated are recombined to form pseudo-time-varying images
of the vocal tract using a simultaneously recorded audio signal.
There is no technical limit on the utterance length or number of
slices that can be so imaged, though the number of repetitions
required may be limited by the subject's stamina. An example of
[pasi] imaged in three sagittal planes is shown; with a Signa GE
0.5 T MR scanner, 360 tokens were reconstructed to form a
sequence of 39 3-slice 16 ms frames. From these, a 3-D volume
was generated for each frame, and tract surfaces outlined
manually. Parameters derived from these include: palate-tongue
distances for [a,s,i]; estimates of tongue volume and of the area
function using only the midsagittal, and then all three slices.
These demonstrate the accuracy and usefulness of the technique.