Although crucial in regulating intracranial hydrodynamics, the cerebral venous system has been rarely studied because of its structural complexity and individual variations. The purpose of our study was to evaluate the organization of cerebral venous system in healthy adults. Phase-contrast magnetic resonance imaging (PC-MRI) was performed in 18 healthy volunteers, in the supine position. Venous, arterial, and cerebrospinal fluid (CSF) flows were calculated. We found heterogeneous individual venous flows and variable side dominance in paired veins and sinuses. In some participants, the accessory epidural drainage preponderated over the habitually dominant jugular outflow. The PC-MRI enabled measurements of venous flows in superior sagittal (SSS), SRS (straight), and TS (transverse) sinuses with excellent detection rates. Pulsatility index for both intracranial (SSS) and cervical (mainly jugular) levels showed a significant increase in pulsatile blood flow in jugular veins as compared with that in SSS. Mean cervical and cerebral arterial blood flows were 714+/-124 and 649+/-178 mL/min, respectively. Cerebrospinal fluid aqueductal and cervical stroke volumes were 41+/-22 and 460+/-149 microL, respectively. Our results emphasize the variability of venous drainage for side dominance and jugular/epidural organization. The pulsatility of venous outflow and the role it plays in the regulation of intracranial pressure require further investigation.

Intracranial lipomas are rare congenital malformations which are neither hematomas nor true neoplasms. They result from the abnormal persistence and maldifferentiation of the meninx primitiva. The majority of such lesions occur near the midline. Around 55% of intracranial lipomas are associated with brain malformations of varying severity. Although they are usually an incidental finding, symptomatic intracranial lipomas are sometimes observed. Surgical excision may result in high morbidity and mortality due to the highly vascular nature of intracranial lipomas and the latter's strong adhesion to the surrounding tissue and is very rarely indicated.

BACKGROUND AND PURPOSE: MR diagnostic of postoperative recurrent cholesteatomas is difficult. Our purpose was to compare multishot fast spin-echo periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER) diffusion-weighted MR imaging (DWI) with array spatial sensitivity encoding technique (ASSET) single-shot echo-planar DWI and late postgadolinium T1-weighted MR imaging for the detection of postoperative recurrent middle ear cholesteatomas with a 3T imaging unit.

These results show that VDs occurring after FS correspond to MA and are not transient ischaemic cerebro-vascular events. We suggest a pathophysiological hypothesis resting on the release of endothelin that would reach the cerebral cortex through a paten foramen ovale.

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