Background

An understanding of CSF flow and its disorders is essential for the management of many neurosurgical conditions. Such an understanding is enhanced by the detection of CSF flow on imaging and its qualitative as well as quantitative assessments. Such a task has posed significant challenges based on routine imaging protocols.

Objective

We present our clinical experience over the last 8 years with T2-weighted 3D spin echo sequences with variable flip angle (SPACE, Cube) that allow better visualisation of CSF flow. When coupled with high resolution 3D-balanced steady-state free precession sequences (CISS, FIESTA), the information gained is second to none in addressing intra- and para-ventricular pathology.

Methods

We present our data with examples from clinical practice clearly demonstrating CSF flow in a variety of pathologies. We also compare the sequences with phase contrast CINE-MRI. Finally, we present data from in vitro studies, assessing flow within shunt tubing.

Results

Areas of CSF flow appear as regions of signal drop out on 3D T2-weighted sequences. The degree of signal drop out is related to the velocity of flow and is equivalent to the flow demonstrated during the highest velocity phase of CINE-MRI.

Conclusions

3D T2-weighted spin echo sequences with variable flip angle afford excellent visualisation of CSF flow, providing similar information to phase contrast CINE-MRI studies. These sequences can be acquired with isotropic 0.7-1mm3 voxels that can be directly uploaded to neuronavigation systems, avoiding the need to perform additional sequences. Results from our in vitro studies suggest that we may be able to use them to assess shunt function in the future.