In this study the potential of using the enhanced procedures for analyzing diffusion weighted data which were acquired according to clinical procedures is further investigated. The result is compared to the reconstruction of the OR based on high…
ID
Source
Brief title
Condition
- Neurological disorders NEC
Synonym
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
An estimate of the anatomically plausible OR tracts for the three datasets as
described earlier, which is based on the percentage of fibers that remain after
all implausible OR tracts are removed from those produced by the probabilistic
tracking algorithm.
Secondary outcome
As secondary study parameter the plausibility of the fiber distribution will be
evaluated compared to the anatomy.
Background summary
In case of refractory localized temporal lobe epilepsy the anterior part of the
temporal lobe and parts of the mesial structures can be removed with an
anterior temporal lobe resection. After surgery approximately 60 to 80% of the
patients become seizure free. However, a visual field deficit in the upper
quadrant of the visual field is a complication that might arise due to
disruption of the most anterior part of the optic radiation (Meyer*s loop),
even according to some publications in up to 100% of the cases.
Since a large inter-subject variability exists in the anterior extent of
Meyer*s loop, assessment of the risk of a visual field deficit is complicated
and therefore accurately localizing and visualizing the optic radiation (OR) is
useful. Previous research has shown that the reconstruction of the OR is
possible by using anatomical MRI acquisition techniques for fiber tracking
(diffusion-weighted tractography). It has furthermore been demonstrated that
using special analysis techniques to process these data improves the
reconstruction of the OR.
Study objective
In this study the potential of using the enhanced procedures for analyzing
diffusion weighted data which were acquired according to clinical procedures is
further investigated. The result is compared to the reconstruction of the OR
based on high resolution diffusion-weighted tractography data, what takes much
longer to acquire and therefore, is not suited for clinical use.
Study design
This is a feasibility study wherein ten healthy volunteers will undergo a short
anatomical scan acquired according to the current clinical protocol with a
limited number (32) of diffusion directions and a high resolution
diffusion-weighted scan (with 128 diffusion directions). fMRI activated upon
visual stimulation is used to delineate the primary visual cortex. The
diffusion-weighted data are processed, resulting in three distinct datasets:
diffusion-weighted data acquired with the clinical protocol and analyzed
according to the standard and to the enhanced analysis procedures and
diffusion-weighted data acquired with the high resolution scan. For these
datasets white matter fibers connecting the visual cortex and the lateral
geniculate nucleus are generated for each of the conditions using a
probabilistic fMRI seeded tractography algorithm. Since there is no ground
truth for white matter fiber tracts a plausibility evaluation procedure will be
applied, which is based on a pre-postoperative comparison study of the OR.
Study burden and risks
The volunteers will undergo one MR scanning session (about 60 minutes in
duration). The extra risk for the participants in this study is negligible.
Sterkselseweg 65
Heeze 5591 VE
NL
Sterkselseweg 65
Heeze 5591 VE
NL
Listed location countries
Age
Inclusion criteria
* > 18 and < 65 years;
* no structural abnormalities based on earlier MR scans;
* no suspicion of further neurological disorders.
* written agreement that unexpected findings will be reported to the person (general practitioner or other medical specialist) as indicated by the volunteer on the MRI checklist;
* subjects should give a written informed consent. The informed consent gives each participant thorough understanding of the purpose, nature and procedures of the examinations and explains the voluntariness of the examinations and the confidentiality of the patients data.
Exclusion criteria
* who cannot meet the mild physical or psychological criteria for prolonged MRI scanning;
* who have a cardiac pacemaker or intracranial metals.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL43386.068.13 |