Related Experiment Videos
Diffusion tensor imaging of early relapsing-remitting multiple sclerosis with histogram analysis using automated
W Rashid1, A Hadjiprocopis, C M Griffin
1MS NMR Research Unit, Department of Neuroinflammation, Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.
Multiple Sclerosis (Houndmills, Basingstoke, England)
|February 6, 2004
Summary
Diffusion tensor imaging reveals early brain abnormalities in multiple sclerosis (MS) patients. Adjusting for brain volume differences improves the detection of these subtle changes in normal-appearing brain tissue.
Area of Science:
- Neuroimaging
- Neurology
- Biomedical Engineering
Background:
- Diffusion tensor imaging (DTI) detects abnormalities in normal-appearing brain tissue (NABT) in multiple sclerosis (MS).
- The early occurrence of these DTI abnormalities in MS remains unclear.
- Whole brain histogram analysis shows promise for detecting subtle changes but faces challenges with segmentation reliability and intersubject brain volume variations causing partial volume errors.
Purpose of the Study:
- To investigate early DTI-detectable abnormalities in normal-appearing brain tissue (NABT) in relapsing-remitting multiple sclerosis (MS).
- To assess the impact of brain parenchymal volume (BPV) differences on DTI histogram analysis in early MS.
- To improve the reproducibility and reliability of DTI histogram analysis in early MS using automated segmentation.
Main Methods:
- Compared 28 early relapsing-remitting MS subjects with 20 healthy controls using whole brain histogram analysis.
- Employed an automated segmentation algorithm to enhance reproducibility and calculated brain parenchymal volumes (BPV) for each subject.
- Analyzed DTI parameters including fractional anisotropy (FA), mean diffusivity, and volume ratio, focusing on mean, peak height, and peak location.
Main Results:
- An increased fractional anisotropy (FA) peak height in the normal-appearing brain tissue (NABT) of MS subjects was observed (P = 0.02), even after accounting for age, gender, and brain parenchymal volume (BPV).
- Further DTI abnormalities in NABT became apparent when BPV differences were excluded from the analysis.
- The study highlights that partial volume effects related to brain volume variations can influence histogram analysis findings.
Conclusions:
- Fractional anisotropy (FA) peak height is elevated in the normal-appearing brain tissue (NABT) of individuals with early multiple sclerosis (MS).
- Partial volume effects, stemming from intersubject brain volume differences, may contribute to observed abnormalities in NABT histogram analysis.
- Correcting for brain volume variations is crucial for reducing potential partial volume edge effects and accurately detecting DTI abnormalities in early MS.