Figure 4
From: High-speed, high-frequency ultrasound, in utero vector-flow imaging of mouse embryos
Three frames (40, 186 and 258 ms relative to start of spectrogram) from the vector flow analysis of the data sequence of Fig. 3. The Doppler spectrogram represents the same region of the liver as was indicated in Fig. 3a. The yellow line in the spectrogram indicates the slow-time point for which the data is displayed. (a) Diastole where the perfusion in the liver was minimal. (b) Late diastolic phase with a reversal of flow. (c) Systolic phase after the spectrogram peaked in the positive flow direction. The white arrows highlight the general direction of local flow vectors in each frame. Flow vectors point in the direction of flow and their color and length scale with the vector magnitude. NP: Negative pulse 93 ms after start of spectrogram, UA: Umbilical artery, UV: Umbilical vein. The full image sequence is available as Movie 2.
