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Updated: Jun 19, 2026
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Diffusion tensor MR imaging in children with pantothenate kinase-associated neurodegeneration with brain iron
R Awasthi1, R K Gupta, R Trivedi
1Department of Radiodiagnosis, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
Insights
High fractional anisotropy (FA) in siblings of patients with Pantothenate Kinase-Associated Neurodegeneration (PKAN) suggests abnormal iron accumulation in deep gray matter nuclei, detectable via diffusion tensor imaging (DTI). This indicates a potential preclinical marker for the condition.
Area of Science:
- Neuroimaging
- Neurodegenerative Diseases
- Biochemistry
Background:
- Iron concentration impacts diffusion tensor imaging (DTI) metrics in deep gray matter nuclei.
- Pantothenate Kinase-Associated Neurodegeneration (PKAN) is characterized by abnormal iron accumulation.
- The
- eye-of-the-tiger sign
- is a hallmark of PKAN on T2*-weighted GRE sequences.
Purpose of the Study:
- To investigate if increased fractional anisotropy (FA) in deep gray nuclei correlates with abnormal iron accumulation in PKAN patients and their siblings.
- To explore DTI metrics in specific deep gray matter nuclei (putamen, CN, GP, SN, ALIC) and within the
- eye-of-the-tiger sign
- lesions.
Main Methods:
- Prospective study of 7 PKAN patients, 5 siblings, and 5 age-matched controls.
- One-way ANOVA with Bonferroni correction to compare DTI metrics (FA, MD) among groups.
- Segmentation and DTI analysis of hypointense and hyperintense regions of the
- eye-of-the-tiger sign
- .
Main Results:
- Significant FA increase in globus pallidus (GP) and substantia nigra (SN) from controls to siblings to patients.
- Higher mean diffusivity (MD) in GP for patients compared to controls and siblings.
- PKAN patients exhibited increased FA and decreased MD in hypointense vs. hyperintense regions of the
- eye-of-the-tiger sign
- .
Conclusions:
- Elevated FA in siblings suggests subclinical iron accumulation in deep gray matter nuclei.
- DTI may detect abnormal iron in PKAN carriers before the characteristic MRI sign is evident.
- FA and MD changes in deep gray matter nuclei are sensitive indicators of PKAN-related iron dysregulation.
Background And Purpose:
It has been reported that iron concentration influences DTI metrics in deep gray matter nuclei. We hypothesized that increased FA in the deep gray nuclei may indicate abnormal iron accumulation in patients with PKAN and their siblings.
Materials And Methods:
Seven patients with the characteristic "eye-of-the-tiger sign," their 5 siblings, and 5 age-matched controls were prospectively studied. One-way ANOVA with Bonferroni post hoc multiple comparisons was used to compare DTI metrics (FA and MD) among subject groups in the putamen, CN, GP, SN, and ALIC. In addition, hypointense and hyperintense regions of the eye-of-the-tiger sign were segmented, and their DTI metrics were compared. In the patient group, the values of DTI metrics in hypointense regions were also compared with those of the ALIC.
Results:
A significant increase in FA values of the GP and SN from controls to the patient group to siblings was observed. In the GP, MD values were significantly higher in patients compared with controls and siblings. The patients showed significantly increased FA with decreased MD in hypointense compared with hyperintense regions of the eye-of-the-tiger sign. No difference in FA values were observed between the ALIC and hypointense regions of the eye-of-the-tiger sign in patients.
Conclusions:
High FA values in siblings of patients with PKAN suggest the presence of abnormal iron in deep gray matter nuclei, even in the absence of its demonstration on T2*-weighted GRE.
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