Variation of lateral ventricular volume during the cardiac cycle observed by MR imaging

CSF pulsation suggests variation in the size of the cerebral ventricles during the cardiac cycle. The arterial blood flow and venous outflow are two major components that contribute to the variation. High-resolution MR imaging with cardiac gating provides sharp delineation of the cerebral ventricles with clear boundaries. Subtle changes in the size of the ventricles during the cardiac cycle are measurable with high precision and accuracy by using a sophisticated automated edge-detection algorithm. In 12 normal individuals, the cerebral ventricles were examined, and the size of the lateral ventricles showed a 10-20% change during the cardiac cycle. The pattern is complex but similar in appearance to the intracranial pressure pulse waveform. The variation suggests that the choroid plexus may play a greater role as a source of CSF pulsation that currently acknowledged. The ability to measure the variations in ventricular volume has clinical implication as a noninvasive method for the diagnosis of diseases with abnormal brain elasticity.