Chasing shadows: what determines DTI metrics in gray matter regions? An in vitro and in vivo study
Language English Country United States Media print-electronic
Document type Journal Article, Research Support, Non-U.S. Gov't
PubMed
23440865
DOI
10.1002/jmri.24065
Knihovny.cz E-resources
- Keywords
- T2 relaxation, basal ganglia, brain iron, diffusion tensor imaging, fractional anisotropy, mean diffusivity,
- MeSH
- Adult MeSH
- Phantoms, Imaging MeSH
- Ferritins metabolism MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Brain cytology metabolism MeSH
- Neurons cytology metabolism MeSH
- Reproducibility of Results MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Sensitivity and Specificity MeSH
- In Vitro Techniques MeSH
- Iron metabolism MeSH
- Diffusion Tensor Imaging instrumentation methods MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Young Adult MeSH
- Male MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Ferritins MeSH
- Iron MeSH
PURPOSE: To characterize the relationship between superparamagnetic ferritin-bound iron and diffusion tensor scalars in vitro, and validate the results in vivo. MATERIALS AND METHODS: The in vitro model consisted of a series of 40-mL 1.1% agarose gels doped with ferritin covering and exceeding those concentrations normally found within healthy human gray matter. Additionally, regions of interest were placed in the caudate, putamen, and globus pallidus of 29 healthy volunteer subjects 19-80 years of age. Carr-Purcell-Meiboom-Gill sequence (CPMG) and diffusion tensor imaging (DTI) data were collected at 1.5 Tesla (T) and 3T in vitro, and at 1.5T in vivo. RESULTS: In vitro, linear relationships were observed between ferritin-bound iron concentration, R2 (1/T2 ) and 1/SNR. Eigenvalue repulsion with increasing R2 (decreasing SNR) was reflected in an artifactual increase of fractional anisotropy. In vivo, similar relationships were observed, with mean diffusivity also decreasing linearly with increasing R2 . Lambda 3 showed the strongest correlation with R2 both in vitro and in vivo. CONCLUSION: The observation that DTI metrics correlate with ferritin-bound iron is an important consideration in the design and interpretation of studies exploring the diffusion characteristics of gray matter regions, especially in studies focused on adolescence as well as diseases associated with altered brain-iron load such as pantothenate kinase-associated neurodegeneration, Huntington disease and multiple system atrophy.
References provided by Crossref.org
Diffusion tensor imaging in the characterization of multiple system atrophy
