Fig. 10.

The mean value of 2 hypoechoic regions, both indicated in Fig. 9(a), was measured. Acceleration factors of 1, 2, 4, 8, 16, and 32 were tested, both for the proposed SPEED method (solid lines) and for a receive beamforming reconstruction (dotted lines). As can be seen in Fig. 9, the material surrounding these hypoechoic regions has a fairly constant echogenicity for all considered cases. Accordingly, increased signal values for these hypoechoic regions fairly directly translate into losses in contrast. As could be expected, increasing acceleration tended to have a negative impact on contrast. Furthermore, replacing our algorithm by a receive beamforming reconstruction significant degraded contrast. Overall, reconstructions using our algorithm and low acceleration settings featured the best contrast. ROI = region of interest.