Brain morphometry in Parkinson’s disease
Brain morphometry in Parkinson’s disease
Abstract
Abstract
Purpose
The purpose of this brain morphometry study was to examine the volumes of
different regions of the brain by research participants with Parkinson’s disease.
Method
To carry out the study, MR (magnetic resonance) images from 956 research
participants from the Parkinson’s Progression Markers Initiative (PPMI) were
used. The research participants were divided into 6 different cohorts. Before
the MR images were used in this study, they had gone through preprocessing
and segmentation using MAPER, where 121 regions including background were
segmented. Once the data were obtained, the segmented regions were converted to
volumes. The investigation was divided into two parts, first it was studied whether
ICV (intracranial volume) differed between the different cohorts. This was done
with the help of a violin plot and two-sided t-tests for each cohort. In the second
part of the study, the individual volumes in the brain were examined. To accomplish
this, hypothesis generation was used on half of each group’s subjects and then the
hypotheses were tested on the other half. Two-tailed t-tests were performed to
examine statistical differences and similarities between the cohorts.
Result
In the study, it was seen that the ICV differed between the different cohorts and
thus on the imaged person’s head. None of the tested regions in the PD (Parkinsons
disease) and SWEDD (scans without evidence for dopaminergic deficit) cohort
showed any significant volume difference. The other three cohorts had two to five
brain regions that showed a significant volume difference
Conclusion
In this brain morphometry study, it was shown that a correction for ICV is needed
to get comparable results for the different cohorts. For the individual volumes, the
results obtained in this study do not agree with previously obtained results. In
further studies, it would therefore have been interesting to divide the brain into
fewer regions, to add together regions that belong together.
Degree
Student essay
Collections
View/ Open
Date
2023-03-02Author
Olivia, Lönkvist
Keywords
Medical physics
Parkinson’s disease
Computational anatomy
Quantitative image analysis
Language
eng