Multi-plane tagging time-of-flight and bipolar gradient phase-encoding and amplitude-weighting NMR microimaging techniques have been employed to study transport in extraembryonic compartments of fertilized quail eggs during the first seven days of incubation. After the fourth day coherent and incoherent motions became visible in certain regions, in particular in the upper part of the albumen. Coherent motions as visualized by deformations of multiplane tagging grids were specified by local velocities less than 1 mm/ a at most. On the other hand, incoherent motions led to much more pronounced phenomena. The multiplane tagging grid completely faded in a region comprising the upper third of the albumen after 4.5 incubation days. Images weighted by signal attenuation owing to incoherent displacements indicate motions in the same region. The fact that a reproducible localization of the motions is only possible when signals from different transients are averaged indicates that the incoherence at least partly is temporal in nature. The signal intensity of a volume selected in the incoherent-motion region consequently fluctuates with time. The Fourier analysis of these fluctuations revealed a distinct pulsation with a frequency of 0.4 Hz.
Bibliographical noteFunding Information:
Acknowledgments-This work was funded by the Alexander von Humboldt Foundation and the Deutsche Forschungsgemeinschaft. J.W. is indebted to the Slovak Academy of Sciences for the support in the course of this study.
- Anisotropic flow pulsations
- Flow mapping
- Incubated quail eggs
- NMR imaging