Increasing frame rate in ultrasound imaging by temporal morphing using tissue Doppler [human heart imaging]

The diagnostic value of ultrasound B-mode sequences of the human heart seems to diminish when the frame rate is low. In this work, we used morphing based on velocity information to improve the quality of interpolated B-mode frames in sequences with low frame rate. Two different sources of information about tissue velocity were investigated: speckle tracking and Doppler signal processing. Based on a priori knowledge of the image, we calculated the velocity field in certain image locations throughout a cardiac cycle. Secondly, we extended the velocity information to the rest of each image frame to produce a velocity estimate for the entire data set. The velocity information was then used to create intermediate, morphed frames, where the frame rate could be chosen arbitrarily. We applied this technique to data previously used in diagnosis. The decimated and morphed sequences were compared to the original ones, and we conclude that much of the diagnostic value is retained in recordings with frame rates in the range of 12-18 frames per second.