The flocculus in computed tomography.
The flocculus may simulate a cerebellopontine angle mass in computed tomography (CT). The CT appearance of the flocculus was compared with acoustic neuroma. Normal internal auditory canals, symmetric cerebellopontine angle cisterns, modest contrast enhancement, and a location posterior to the porus acousticus distinguish the flocculus from an acoustic neuroma.
Anatomía radiológica del espacio subaracnoideo: Las cisternas. Revisión
Introduction: Encephalon cisterns constitute a of cephalorrhachidea liquid reservoir with a greater volume than that one of the ventricles; they contain blood vessels and venous structures; they are continual with each others and they communicate with the ventricular system through the medium and lateral holes, located in the fourth ventricle. Material and method: The magnetic resonance (MR) avoids invasive procedures by means of sequences that allow to observe the cephalorrhachidean liquid without contrast, for example the T2-P and the FIESTA sequence. The neumocisternography and the injection of hydrosoluble medium into the subarachnoid space have became obsolete. Results and remarks: We describe the 15 more important cisterns of the subarachnoid space, classifying them in four groups: I. Posterior fossa (1. Bulbar, 2. Protuberance or pontine, 3. Magna, 4. Ponto cerebellar, 5. Superior cerebellar or vermiana). II. Perimesencephalic (6. Interpeduncular, 7. Crural, 8. Ambiens, 9. Cuadrigeminal). III. (10. Retrothalamic, 11. Interposed veil, 12. Of the callosum body). IV Suprasellar (13. chiasmatic, 14. Terminal Lamina, 15. Sylvian). Conclusions: This revision shows in didactic form the basic information that is to remember of each cistern (content and anatomical relation with the rest of the encephalic structures), supported of schemes, images of TC and MR.
Mean field model of a game for power
Abstract Our aim is to model a game for power (equivalent to total energy) as a dynamical process, where an excess of power possessed by a player allows him to gain even more power. Such a positive feedback is often termed as the Matthew effect. Analytical and numerical methods allow to identify a set of stationary states, i.e. fixed points of the model dynamics. The positions of the unstable fixed points give an insight on the basins of attraction of the stable fixed points. The results are interpreted in terms of modeling of coercive power.