Gadolinium-based contrast agents (GBCA) are used worldwide for enhanced MRI examinations, including heart and vessels. Gadolinium is a highly toxic heavy metal. If used in GBCA it must be tightly bound to ligands. The configuration of ligands influences the stability of the GBCA and two types of chelates have been used. Macrocyclic chelates offer better protection and binding of gadolinium ion than linear chelates with a flexible open chain - gadolinium could be more easily released from the latter ones. GBCAs are excreted from the body mostly by the kidneys, which is of importance in chronic kidney disease.Two states are related to gadolinium: nephrogenic systemic fibrosis (NSF) and gadolinium body storage. NSF is a severe and debilitating disease, directly connected to gadolinium toxicity, proven after the use of linear chelates. Due to strict recommendations of radiology societies, NSF was practically eradicated. Gadolinium deposition was observed especially in bones and in some brain areas: in dentate nucleus and in globus pallidus, even years after the GBCA administration. The form of the storage (chelated or free), as well as their clinical impact, are not clear, but first observations of "gadolinium deposition disease" have been reported.
- MeSH
- bezpečnost pacientů MeSH
- časové faktory MeSH
- gadolinium škodlivé účinky metabolismus MeSH
- globus pallidus metabolismus MeSH
- hodnocení rizik MeSH
- kontrastní látky škodlivé účinky metabolismus MeSH
- kosti a kostní tkáň metabolismus MeSH
- lidé MeSH
- magnetická rezonanční tomografie škodlivé účinky MeSH
- mozečková jádra metabolismus MeSH
- nefrogenní systémová fibróza chemicky indukované diagnóza MeSH
- obsah radioaktivních látek v organizmu MeSH
- organokovové sloučeniny škodlivé účinky metabolismus MeSH
- prediktivní hodnota testů MeSH
- rizikové faktory MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Huntington's disease (HD) is an inherited neurodegenerative disorder with progressive impairment of motor, behavioral and cognitive functions. The clinical features of HD are closely related to the degeneration of the basal ganglia, predominantly the striatum. The main striatal output structure, the globus pallidus, strongly accumulates metalloprotein-bound iron, which was recently shown to influence the diffusion tensor scalar values. To test the hypothesis that this effect dominates in the iron-rich basal ganglia of HD patients, we examined the globus pallidus using DTI and T2 relaxometry sequences. Quantitative magnetic resonance (MR), clinical and genetic data (number of CAG repeats) were obtained from 14 HD patients. MR parameters such as the T2 relaxation rate (RR), fractional anisotropy (FA) and mean diffusivity (MD) were analysed. A positive correlation was found between RR and FA (R2=0.84), between CAG and RR (R2=0.59) and between CAG and FA (R2=0.44). A negative correlation was observed between RR and MD (R2=0.66). A trend towards correlation between CAG and MD was noted. No correlation between MR and clinical parameters was found. Our results indicate that especially magnetic resonance FA measurements in the globus pallidus of HD patients may be strongly affected by metalloprotein-bound iron accumulation.
- MeSH
- bazální ganglia patologie MeSH
- dospělí MeSH
- expanze repetic DNA MeSH
- globus pallidus metabolismus patologie MeSH
- Huntingtonova nemoc genetika patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční spektroskopie MeSH
- senioři MeSH
- železo metabolismus MeSH
- zobrazování difuzních tenzorů MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Iron deposits in the human brain can be considered as intrinsic contrast agents for magnetic resonance imaging and are used as markers of neurodegeneration accompanied by brain-iron accumulation. We studied one of them - panthotenate-kinase associated neurodegeneration (PKAN) - by using relaxometry at 1.5, 3.0 and 7 T in a group of six patients; we also measured a group of five volunteers for comparison. Based on the magnetic field dependency of antiferromagnetic ferritin and maghemite iron oxide nanoparticle relaxivities, we derived a two-component model for the description of iron deposits in the globus pallidus of PKAN patients. According to this model, we estimated the iron content in PKAN patients as 391 µg/ml of antiferromagnetic iron (ferritin) and 1.1 µg/ml of ferrimagnetic iron, compared with 178 µg/ml of iron in ferritin found in controls. This two-component model explains the nonlinear shape of the relaxometric curves in in vivo measurements of the relaxation rates of PKAN patients and is supported by histological findings in the original reports on PKAN patients.
- MeSH
- dospělí MeSH
- ferritin metabolismus MeSH
- globus pallidus metabolismus patologie MeSH
- Hallervordenův-Spatzův syndrom metabolismus patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie metody MeSH
- mladiství MeSH
- železité sloučeniny metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
