Clinical Validity of the MoSeSS RARE-Sequence at CSF Flow Disturbances

Abstract

The development of non-invasive diagnostic methods is a matter of great importance. This paper describes Motion Sensitized Single Shot RARE Sequences (MoSeSS) as a new, non-invasive diagnostic method in CSF-flow disturbances. The range of applications and clinical validity are examined.

The strongly T2-weighted RARE-sequence displays selectively unbound water. The addition of flowencoding gradients shows moving spins flow-dependently as a signal reduction. ECG-triggering enablesthe registration of present flow phases, and the CSF-flow can be observed as cine-mode in quasi real-time. Thirty healthy subjects and 137 patients from subcollectives with diverse CSF-flow disturbances were investigated.

The MoSeSS RARE-sequence provides reliable information in occlusion or stenoses of the inner CSF-spaces and in ventriculocisternostomies. Indirect signs of shunt dysfunction are CSF turbulences which correlate in degree with the increase in CSF pressure. Determination of localization and degree of dural impairment in traumatic or postoperative pseudomeningoceles is dependent on the activity of the CSF-flow at the leak. Depending on the stage of NPH, a variably marked active flow oscillation in the aqueduct and in the third ventricle is shown. Liquorrhoea has no definable flow detectable with the MoSeSS RARE-sequence. Vascular pulsation can make differentiation of the CSF-flow from artefacts difficult near larger vessels.

The MoSeSS-RARE-Sequence is a fast, non-invasive and radiation-free method, which yields valid clinical information on circulation disturbances in the inner CSF-spaces. With the cine-mode technique, CSF movements can be observed in quasi real-time. Positive enhancement of the CSF is necessary in assessing processes with an undefined, non-detectable flow.