What is the relative distribution of spinal subarachnoid space volumetric compliance in healthy subjects?

Personel

• Bryn Martin
• Francesco Santini
• Francis Loth
• Nikolaos Stergiopulos
• Matthias Stuber

The problem

Craniospinal compliance has been thought to be an important indicator of craniospinal health. However, a non-invasive technique for assessment of craniospinal compliance is not available. The proposed pilot study aims to investigate the feasibility of a novel non-invasive 4D MR flow quantification technique5 to measure the relative distribution of volumetric compliance of the spinal subarachnoid space (Figure 1).

The relative distribution of spinal canal compliance can be measured by integration of the velocity over a manually selected cross-sectional region of the spinal canal for an entire cardiac cycle as detailed by Martin et al. 3,4. If the entire 4D flow field in the spinal subarachnoid space is known5, then it is possible to obtain the relative distribution of compliance along the entire spinal canal which may be indicative of craniospinal health.

Hypothesis and research objectives

We hypothesize that in healthy persons most of the volumetric compensation of the CSF pulsation takes place in the cervical subarachnoid space. The goal of this research is thus to validate the feasibility of a novel 4D MR flow protocol for measurement of the distribution of spinal canal compliance in a healthy person.

Methods and study outline

A. in vivo MR measurements.

Our approach is to obtain 4D CSF flow velocity measurements on a single healthy subject using the protocol developed by Santini et al.5.

B. processing of MR data.

The relative distribution of spinal canal compliance will be calculated based on the CSF flow velocity measurements using a technique similar to Martin et al.4. These measurements will be compared to those already available in the literature1,2.

Expected results and potential impact

The proposed work will determine if the non-invasive MR protocol is capable of measuring the distribution of compliance in the spinal canal in a single healthy volunteer. If proven efficacious, the test could be further explored with healthy volunteers and patients, and has the potential to provide a clinically useful tool for assessment of relative distribution in craniospinal compliance.

Preliminary results

To be posted

References

1. Alperin N, Sivaramakrishnan A, Lichtor T: Magnetic resonance imaging-based measurements of cerebrospinal fluid and blood flow as indicators of intracranial compliance in patients with Chiari malformation. J Neurosurg 103:46-52, 2005

2. Alperin NJ, Lee SH, Loth F, Raksin PB, Lichtor T: MR-Intracranial pressure (ICP): a method to measure intracranial elastance and pressure noninvasively by means of MR imaging: baboon and human study. Radiology 217:877-885, 2000

3. Kalata W: Numerical simulation of cerebrospinal fluid motion within the spinal canal. Masters Thesis Chicago, University of Illinois at Chicago, 2002

4. Martin BA, Kalata W, Loth F, Royston TJ, Oshinski JN: Syringomyelia hydrodynamics: an in vitro study based on in vivo measurements. J Biomech Eng 127:1110-1120, 2005

5. Santini F, Wetzel SG, Bock J, Markl M, Scheffler K: Time-resolved three-dimensional (3D) phase-contrast (PC) balanced steady-state free precession (bSSFP). Magn Reson Med, 2009