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Updated: Aug 26, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Diffusion tensor MRI correlates with executive dysfunction in patients with ischaemic leukoaraiosis
M O'Sullivan1, R G Morris, B Huckstep
1Clinical Neuroscience, St George's Hospital Medical School, London SW17, UK.
Background:
Cerebral small vessel disease is a common cause of vascular dementia. Both discrete lacunar infarcts and more diffuse ischaemic changes, seen as confluent high signal (leukoaraiosis) on T2 weighted magnetic resonance imaging (MRI), occur. However, there is a weak correlation between T2 lesion load and cognitive impairment. Diffusion tensor MRI (DTI) is a new technique that may provide a better index of white matter damage.
Objectives:
To determine whether DTI measures are correlated more strongly with cognitive performance than lesion load on T2 weighted images, and whether these correlations are independent of conventional MRI parameters.
Methods:
36 patients with ischaemic leukoaraiosis (leukoaraiosis plus a previous lacunar stroke) and 19 healthy volunteers underwent DTI, conventional MRI, and neuropsychological assessment.
Results:
On DTI, diffusivity was increased both within lesions and in normal appearing white matter. Mean diffusivity of normal appearing white matter correlated with full scale IQ (r = -0.46, p = 0.009) and tests of executive function. These correlations remained significant after controlling for age, sex, brain volume, and T1/T2 lesion volumes. No significant correlation was identified between T2 lesion load and IQ or neuropsychological scores. Of conventional measures, brain volume correlated best with cognitive function.
Conclusions:
Diffusion tensor measurements correlate better with cognition than conventional MRI measures. They may be useful in monitoring disease progression and as a surrogate marker for treatment trials. The findings support the role of white matter damage and disruption of white matter connections in the pathogenesis of cognitive impairment in cerebral small vessel disease.
Insights
Diffusion tensor imaging (DTI) better reflects cognitive decline in cerebral small vessel disease than traditional MRI. DTI measures of white matter integrity show stronger correlations with cognitive function, aiding in disease monitoring and treatment trials.
Area of Science:
- Neurology
- Radiology
- Neuroimaging
Background:
- Cerebral small vessel disease is a primary cause of vascular dementia.
- Leukoaraiosis and lacunar infarcts are common MRI findings, but T2 lesion load poorly correlates with cognitive impairment.
- Diffusion tensor MRI (DTI) offers a potentially superior method for assessing white matter damage.
Purpose of the Study:
- To compare the correlation of DTI measures with cognitive performance against T2 lesion load.
- To determine if DTI correlations are independent of conventional MRI parameters.
Main Methods:
- 36 patients with ischaemic leukoaraiosis and 19 healthy controls underwent DTI, conventional MRI, and neuropsychological testing.
- Diffusion tensor imaging (DTI) and conventional MRI parameters were analyzed.
- Neuropsychological assessments evaluated cognitive function.
Main Results:
- Increased diffusivity was observed on DTI within lesions and normal-appearing white matter.
- Mean diffusivity in normal-appearing white matter significantly correlated with IQ and executive function (r = -0.46, p = 0.009).
- T2 lesion load did not correlate with cognitive scores, while brain volume showed the best correlation among conventional measures.
Conclusions:
- DTI measurements demonstrate a stronger correlation with cognitive function compared to conventional MRI.
- DTI may serve as a valuable surrogate marker for disease progression and treatment efficacy in clinical trials.
- White matter damage and disrupted connectivity are implicated in cognitive impairment in cerebral small vessel disease.
