Visualization of changing cervical vein geometry of the healthy population

Chronic cerebro-spinal venous insufficiency (CCSVI) is a condition
characterised by anomalies in the main veins draining the central nervous
system (CNS) that disturb the normal outflow of blood from the CNS to the
heart. CCSVI is linked to several CNS disorders, such as idiopathic
intracranial hypertension, traumatic brain injury, senile dementia and
hydrocephalous. Therefore, it is important to better understand the cerebral
venous pathways. Previous studies have shown that these pathways depend on the
body position. In supine position, the cerebral venous drainage through the
internal jugular vein (IJV) is increased compared to upright position. In
upright position, the IJVs collapse and the blood goes primarily through the
paravertebral venous plexus. Most of the research of cerebral venous pathways
are performed in supine position, while humans spend most of the time in
upright position. Studies to investigate postural changes in cerebral venous
pathways may contribute to the understanding of CCSVI caused by insufficient
cerebral venous drainage.

Rotating low-field MRI offers the opportunity to visualize the neck veins in
different positions to study how these pathways differ with alternating body
positions. For low-field MRI no standardized non-contrast-enhanced protocol is
developed to evaluate the geometry of extracranial veins. This research aims to
contribute to a better understanding of postural changes affecting the
extracranial venous pathways. An explorative study will be conducted to
evaluate the possibilities of an open 0.25T MRI-system to visualize the
geometry of the IJVs and external jugular veins of healthy subjects in supine,
upright and intermediate positions. The size and geometry of the veins will be
measured to evaluate how these parameters relate to the postural position. This
pilot study will assess the feasibility for a larger study, with the aim to
identify the normal variation of geometry of the extracranial veins in
different postural positions.

This is an explorative prospective cohort study in 15 healthy volunteers. All
the subjects will be volunteering students or employees of the University of
Twente (UT). Each subject will be scanned in the sub-mandibular region, at
scanner inclinations from 90º (sitting, analogous to upright), 69º 45º, 21º and
0º (supine position).

The burden associated with participation is that subjects who are already daily
in the TechMed Centre (University of Twente) need to visit the MRI scanner once
for a scan session of 45 minutes duration. To perform the upright scan, the
participant needs to sit still for 6 minutes first at 90°. After that, the MRI
table will be rotated back to 69°, 45°, 21°, and 0° (=supine), where also
6-minute scans will be made. Due to the sitting position of the participants,
the possible effect of experiencing dizziness or light-headedness that can
occur in standing position will be much less and can be considered negligible.
This is due to the possibility for the participants of using and moving the
legs, which will prevent this effect from happening. Of course, participant do
always have the chance to communicate with the researchers during the scan and
may always indicate on their own initiative to end the investigation if they
want.