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KOZLER P, HERYNEK V, MAREŠOVÁ D, PEREZ P, ŠEFC L, POKORNÝ J. Effect of Methylprednisolone on Experimental Brain Edema in Magnetic Resonance Imaging. Physiol Res 2020; 69:919-926. [DOI: 10.33549/physiolres.934460] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Magnetic resonance imaging has been used for evaluating of a brain edema in experimental animals to assess cytotoxic and vasogenic edema by the apparent diffusion coefficient (ADC) and T2 imaging. This paper brings information about the effectiveness of methylprednisolone (MP) on experimental brain edema. A total of 24 rats were divided into three groups of 8 animals each. Rats with cytotoxic/intracellular brain edema induced by water intoxication were assigned to the group WI. These rats also served as the additional control group CG when measured before the induction of edema. A third group (WIMP) was intraperitoneally administered with methylprednisolone 100 mg/kg during water intoxication treatment. The group WI+MP was injected with methylprednisolone 50 mg/kg into the carotid artery within two hours after the water intoxication treatment. We evaluated the results in four groups. Two control groups (CG, WI) and two experimental groups (WIMP, WI+MP). Rats were subjected to MR scanning 24 h after edema induction. We observed significantly increased ADC values in group WI in both evaluated areas – cortex and hippocampus, which proved the occurrence of experimental vasogenic edema, while ADC values in groups WIMP and WI+MP were not increased, indicating that the experimental edema was not developed and thus confirming the protective effect of MP.
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Affiliation(s)
- P KOZLER
- Institute of Physiology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - V HERYNEK
- Center for Advanced Preclinical Imaging, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - D MAREŠOVÁ
- Institute of Physiology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - P PEREZ
- Center for Advanced Preclinical Imaging, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - L ŠEFC
- Center for Advanced Preclinical Imaging, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - J POKORNÝ
- Institute of Physiology, First Faculty of Medicine, Charles University, Prague, Czech Republic
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Dezortova M, Lescinskij A, Dusek P, Herynek V, Acosta‐Cabronero J, Bruha R, Jiru F, Robinson SD, Hajek M. Multiparametric Quantitative Brain MRI in Neurological and Hepatic Forms of Wilson's Disease. J Magn Reson Imaging 2019; 51:1829-1835. [DOI: 10.1002/jmri.26984] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 12/23/2022] Open
Affiliation(s)
- Monika Dezortova
- MR Unit, Department of Diagnostic and Interventional RadiologyInstitute for Clinical and Experimental Medicine Prague Czech Republic
| | - Artem Lescinskij
- MR Unit, Department of Diagnostic and Interventional RadiologyInstitute for Clinical and Experimental Medicine Prague Czech Republic
- Department of Radiology, First Faculty of MedicineCharles University and General University Hospital Prague Czech Republic
| | - Petr Dusek
- Department of Radiology, First Faculty of MedicineCharles University and General University Hospital Prague Czech Republic
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of MedicineCharles University and General University Hospital Prague Czech Republic
| | - Vit Herynek
- MR Unit, Department of Diagnostic and Interventional RadiologyInstitute for Clinical and Experimental Medicine Prague Czech Republic
- Center for Advanced Preclinical Imaging, First Faculty of MedicineCharles University Prague Czech Republic
| | | | - Radan Bruha
- Fourth Department of Internal Medicine, First Faculty of MedicineCharles University and General University Hospital Prague Czech Republic
| | - Filip Jiru
- MR Unit, Department of Diagnostic and Interventional RadiologyInstitute for Clinical and Experimental Medicine Prague Czech Republic
| | - Simon D. Robinson
- High Field MR Centre, Department of Biomedical Imaging and Image‐guided TherapyMedical University of Vienna Vienna Austria
| | - Milan Hajek
- MR Unit, Department of Diagnostic and Interventional RadiologyInstitute for Clinical and Experimental Medicine Prague Czech Republic
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Goede LL, Pflugrad H, Schmitz B, Lanfermann H, Tryc AB, Barg-Hock H, Klempnauer J, Weissenborn K, Ding XQ. Quantitative magnetic resonance imaging indicates brain tissue alterations in patients after liver transplantation. PLoS One 2019; 14:e0222934. [PMID: 31553760 PMCID: PMC6760889 DOI: 10.1371/journal.pone.0222934] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/10/2019] [Indexed: 12/28/2022] Open
Abstract
PURPOSE To investigate cerebral microstructural alterations in patients treated with calcineurin inhibitors (CNI) after orthotopic liver transplantation (OLT) using quantitative magnetic resonance imaging (qMRI) and a cross-sectional study design. METHODS Cerebral qMRI was performed in 85 patients in a median 10 years after OLT compared to 31 healthy controls. Patients were treated with different dosages of CNI or with a CNI-free immunosuppression (CNI-free: n = 19; CNI-low: n = 36; CNI-standard: n = 30). T2-, T2*- and T2'- relaxation times, as well as apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured in brain gray and white matter by using the regions of interest method. RESULTS In comparison to controls, patients revealed significantly increased T2, T2*, T2', ADC and reduced FA, predominantly in the frontal white matter, indicating microstructural brain alterations represented by increased free water (increased T2), reduced neuronal metabolism (increased T2') and a lower degree of spatial organization of the nervous fibers (reduced FA). CNI-low and CNI-free patients showed more alterations than CNI-standard patients. Analysis of their history revealed impairment of kidney function while under standard CNI dose suggesting that these patients may be more vulnerable to toxic CNI side-effects. CONCLUSION Our findings suggest that the individual sensitivity to toxic side effects should be considered when choosing an appropriate immunosuppressive regimen in patients after liver transplantation.
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Affiliation(s)
- Lukas Laurids Goede
- Department of Neurology, Hannover Medical School, Hannover, Germany
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
- Integrated Research and Treatment Centre Transplantation (IFB-Tx), Hannover Medical School, Hannover, Germany
| | - Henning Pflugrad
- Department of Neurology, Hannover Medical School, Hannover, Germany
- Integrated Research and Treatment Centre Transplantation (IFB-Tx), Hannover Medical School, Hannover, Germany
| | - Birte Schmitz
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| | - Heinrich Lanfermann
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
| | - Anita Blanka Tryc
- Department of Neurology, Hannover Medical School, Hannover, Germany
- Integrated Research and Treatment Centre Transplantation (IFB-Tx), Hannover Medical School, Hannover, Germany
| | - Hannelore Barg-Hock
- Clinic for Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany
| | - Jürgen Klempnauer
- Clinic for Visceral and Transplant Surgery, Hannover Medical School, Hannover, Germany
| | - Karin Weissenborn
- Department of Neurology, Hannover Medical School, Hannover, Germany
- Integrated Research and Treatment Centre Transplantation (IFB-Tx), Hannover Medical School, Hannover, Germany
| | - Xiao-Qi Ding
- Institute of Diagnostic and Interventional Neuroradiology, Hannover Medical School, Hannover, Germany
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McPhee KC, Wilman AH. Limitations of skipping echoes for exponential T2fitting. J Magn Reson Imaging 2018; 48:1432-1440. [DOI: 10.1002/jmri.26052] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 03/27/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Kelly C. McPhee
- Department of Physics; University of Alberta; Edmonton Alberta Canada
- Department of Biomedical Engineering; University of Alberta; Edmonton Alberta Canada
| | - Alan H. Wilman
- Department of Physics; University of Alberta; Edmonton Alberta Canada
- Department of Biomedical Engineering; University of Alberta; Edmonton Alberta Canada
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Sparacia G, Cannella R, Lo Re V, Mamone G, Sakai K, Yamada K, Miraglia R. Brain-core temperature of patients before and after orthotopic liver transplantation assessed by DWI thermometry. Jpn J Radiol 2018; 36:324-330. [DOI: 10.1007/s11604-018-0729-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 03/15/2018] [Indexed: 10/17/2022]
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Patsula V, Kosinová L, Lovrić M, Ferhatovic Hamzić L, Rabyk M, Konefal R, Paruzel A, Šlouf M, Herynek V, Gajović S, Horák D. Superparamagnetic Fe3O4 Nanoparticles: Synthesis by Thermal Decomposition of Iron(III) Glucuronate and Application in Magnetic Resonance Imaging. ACS APPLIED MATERIALS & INTERFACES 2016; 8:7238-47. [PMID: 26928653 DOI: 10.1021/acsami.5b12720] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Monodisperse superparamagnetic Fe3O4 nanoparticles coated with oleic acid were prepared by thermal decomposition of Fe(III) glucuronate. The shape, size, and particle size distribution were controlled by varying the reaction parameters, such as the reaction temperature, concentration of the stabilizer, and type of high-boiling-point solvents. Magnetite particles were characterized by transmission electron microscopy (TEM), as well as electron diffraction (SAED), X-ray diffraction (XRD), dynamic light scattering (DLS), and magnetometer measurements. The particle coating was analyzed by atomic absorption spectroscopy (AAS) and attenuated total reflection (ATR) Fourier transform infrared spectroscopy (FTIR) spectroscopy. To make the Fe3O4 nanoparticles dispersible in water, the particle surface was modified with α-carboxyl-ω-bis(ethane-2,1-diyl)phosphonic acid-terminated poly(3-O-methacryloyl-α-D-glucopyranose) (PMG-P). For future practical biomedical applications, nontoxicity plays a key role, and the PMG-P&Fe3O4 nanoparticles were tested on rat mesenchymal stem cells to determine the particle toxicity and their ability to label the cells. MR relaxometry confirmed that the PMG-P&Fe3O4 nanoparticles had high relaxivity but rather low cellular uptake. Nevertheless, the labeled cells still provided visible contrast enhancement in the magnetic resonance image. In addition, the cell viability was not compromised by the nanoparticles. Therefore, the PMG-P&Fe3O4 nanoparticles have the potential to be used in biomedical applications, especially as contrast agents for magnetic resonance imaging.
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Affiliation(s)
- Vitalii Patsula
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic , Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
| | - Lucie Kosinová
- Institute for Clinical and Experimental Medicine , Vídeňská 1958/9, 140 21 Prague 4, Czech Republic
| | - Marija Lovrić
- University of Zagreb School of Medicine , Croatian Institute for Brain Research, Salata 12, HR-10000 Zagreb, Croatia
| | - Lejla Ferhatovic Hamzić
- University of Zagreb School of Medicine , Croatian Institute for Brain Research, Salata 12, HR-10000 Zagreb, Croatia
| | - Mariia Rabyk
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic , Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
| | - Rafal Konefal
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic , Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
| | - Aleksandra Paruzel
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic , Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
| | - Miroslav Šlouf
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic , Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
| | - Vít Herynek
- Institute for Clinical and Experimental Medicine , Vídeňská 1958/9, 140 21 Prague 4, Czech Republic
| | - Srećko Gajović
- University of Zagreb School of Medicine , Croatian Institute for Brain Research, Salata 12, HR-10000 Zagreb, Croatia
| | - Daniel Horák
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic , Heyrovského nám. 2, 162 06 Prague 6, Czech Republic
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Novotna B, Turnovcova K, Veverka P, Rössner P, Bagryantseva Y, Herynek V, Zvatora P, Vosmanska M, Klementova M, Sykova E, Jendelova P. The impact of silica encapsulated cobalt zinc ferrite nanoparticles on DNA, lipids and proteins of rat bone marrow mesenchymal stem cells. Nanotoxicology 2015; 10:662-70. [PMID: 26581309 DOI: 10.3109/17435390.2015.1107144] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Nanomaterials are currently the subject of intense research due to their wide variety of potential applications in the biomedical, optical and electronic fields. We prepared and tested cobalt zinc ferrite nanoparticles (Co0.5Zn0.5Fe2O4+γ [CZF-NPs]) encapsulated by amorphous silica in order to find a safe contrast agent and magnetic label for tracking transplanted cells within an organism using magnetic resonance imaging (MRI). Rat mesenchymal stem cells (rMSCs) were labeled for 48 h with a low, medium or high dose of CZF-NPs (0.05; 0.11 or 0.55 mM); silica NPs (Si-NPs; 0.11 mM) served as a positive control. The internalization of NPs into cells was verified by transmission electron microscopy. Biological effects were analyzed at the end of exposure and after an additional 72 h of cell growth without NPs. Compared to untreated cells, Annexin V/Propidium Iodide labeling revealed no significant cytotoxicity for any group of treated cells and only a high dose of CZF-NPs slowed down cell proliferation and induced DNA damage, manifested as a significant increase of DNA-strand breaks and oxidized DNA bases. This was accompanied by high concentrations of 15-F2t-isoprostane and carbonyl groups, demonstrating oxidative injury to lipids and proteins, respectively. No harmful effects were detected in cells exposed to the low dose of CZF-NPs. Nevertheless, the labeled cells still exhibited an adequate relaxation rate for MRI in repeated experiments and ICP-MS confirmed sufficient magnetic label concentrations inside the cells. The results suggest that the silica-coated CZF-NPs, when applied at a non-toxic dose, represent a promising contrast agent for cell labeling.
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Affiliation(s)
- Bozena Novotna
- a Department of Genetic Ecotoxicology , Institute of Experimental Medicine AS CR , v.v.i., Prague , Czech Republic
| | - Karolina Turnovcova
- a Department of Genetic Ecotoxicology , Institute of Experimental Medicine AS CR , v.v.i., Prague , Czech Republic
| | - Pavel Veverka
- b Institute of Physics, AS CR, v.v.i. , Prague , Czech Republic
| | - Pavel Rössner
- a Department of Genetic Ecotoxicology , Institute of Experimental Medicine AS CR , v.v.i., Prague , Czech Republic
| | - Yana Bagryantseva
- a Department of Genetic Ecotoxicology , Institute of Experimental Medicine AS CR , v.v.i., Prague , Czech Republic
| | - Vit Herynek
- c Institute for Clinical and Experimental Medicine , Prague , Czech Republic
| | | | - Magda Vosmanska
- e University of Chemistry and Technology , Prague , Czech Republic , and
| | - Mariana Klementova
- f New Technologies - Research Centre, University of West Bohemia , Pilsen , Czech Republic
| | - Eva Sykova
- a Department of Genetic Ecotoxicology , Institute of Experimental Medicine AS CR , v.v.i., Prague , Czech Republic
| | - Pavla Jendelova
- a Department of Genetic Ecotoxicology , Institute of Experimental Medicine AS CR , v.v.i., Prague , Czech Republic
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Wagnerová D, Herynek V, Dezortová M, Marusič P, Kršek P, Zámečník J, Jírů F, Škoch A, Hájek M. The Relationships Between Quantitative MR Parameters in Hippocampus in Healthy Subjects and Patients With Temporal Lobe Epilepsy. Physiol Res 2015; 64:407-17. [PMID: 25536324 DOI: 10.33549/physiolres.932846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We introduce a new magnetic resonance (MR) method based on a pixel-by-pixel image processing to examine relationships between metabolic and structural processes in the pathologic hippocampus. The method was tested for lateralization of the epileptogenic zone in patients with temporal lobe epilepsy (TLE). Twenty patients with drug-resistant TLE and fifteen healthy controls were examined at 3T. The measurement protocol contained T2-weighted MR images, spectroscopic imaging, diffusion tensor imaging and T2 relaxometry. Correlations between quantitative MR parameters were calculated on a pixel-by-pixel basis using the CORIMA program which enables automated pixel identification in the normal tissue according to control data. All MR parameters changed in the anteroposterior direction in the hippocampus and correlation patterns and their slopes differed between patients and controls. Combinations of T2 relaxation times with metabolite values represent the best biomarkers of the epileptogenic zone. Correlations with mean diffusivity did not provide sufficiently accurate results due to diffusion image distortions. Quantitative MR analysis non-invasively provides a detailed description of hippocampal pathology and may represent complementary tool to the standard clinical protocol. However, the automated processing should be carefully monitored in order to avoid possible errors caused by MR artifacts.
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Affiliation(s)
- D Wagnerová
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
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Syka M, Keller J, Klempíř J, Rulseh AM, Roth J, Jech R, Vorisek I, Vymazal J. Correlation between relaxometry and diffusion tensor imaging in the globus pallidus of Huntington's disease patients. PLoS One 2015; 10:e0118907. [PMID: 25781024 PMCID: PMC4362949 DOI: 10.1371/journal.pone.0118907] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 01/18/2015] [Indexed: 11/18/2022] Open
Abstract
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.
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Affiliation(s)
- Michael Syka
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
- International Clinical Research Center, St. Anne´s University Hospital, Brno, Czech Republic
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
- * E-mail:
| | - Jiří Keller
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
- Department of Neurology, 3rd Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Jiří Klempíř
- Department of Neurology and Center of Clinical Neuroscience, 1st Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic
- Institute of Anatomy, 1st Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Aaron M. Rulseh
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
- Department of Radiology, 1st Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic
| | - Jan Roth
- Department of Neurology and Center of Clinical Neuroscience, 1st Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic
| | - Robert Jech
- Department of Neurology and Center of Clinical Neuroscience, 1st Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Prague, Czech Republic
| | - Ivan Vorisek
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, v.v.i., Prague, Czech Republic
| | - Josef Vymazal
- Department of Radiology, Na Homolce Hospital, Prague, Czech Republic
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Herynek V, Wagnerová D, Malucelli A, Vymazal J, Sameš M, Hájek M. Alterations in the basal ganglia in patients with brain tumours may be due to excessive iron deposition. Oncol Lett 2014; 9:43-46. [PMID: 25435931 PMCID: PMC4246608 DOI: 10.3892/ol.2014.2638] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 09/26/2014] [Indexed: 11/06/2022] Open
Abstract
The accumulation of iron in the brain is a common physiological process. However, alterations in the deposition of iron or other paramagnetic substances are associated with various diseases. In the present study, the deposition of paramagnetic substances in patients with brain tumours was evaluated using T2 relaxometry. A total of 23 patients with untreated tumours or with recurrent tumours following treatment, together with a group of 19 age-matched healthy controls, were examined using T2 relaxometry at 3T. The relaxation times in the basal ganglia, thalamus and white matter were evaluated. Significantly lower T2 relaxation times were identified in the basal ganglia and thalamus of the patients with tumours, as compared with those of the controls (P<0.05). No statistically significant difference was identified between patients with untreated or recurrent brain tumours. The reduction in T2 relaxation times in the brain tumour patients was possibly caused by the accumulation of iron, since iron homeostasis is known to be altered in patients with tumours. We propose that increased iron deposition is a consequence of a higher risk of oxidative stress caused by an increased iron concentration in the plasma or cerebrospinal fluid.
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Affiliation(s)
- Vít Herynek
- Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Vídeňská, Prague 14021, Czech Republic
| | - Dita Wagnerová
- Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Vídeňská, Prague 14021, Czech Republic
| | - Alberto Malucelli
- Department of Neurosurgery, JE Purkyně University and Masaryk Hospital, Sociální péče, Ústí nad Labem 40113, Czech Republic
| | - Josef Vymazal
- Department of Radiology, Na Homolce Hospital, Roentgenova, Prague 15030, Czech Republic
| | - Martin Sameš
- Department of Neurosurgery, JE Purkyně University and Masaryk Hospital, Sociální péče, Ústí nad Labem 40113, Czech Republic
| | - Milan Hájek
- Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Vídeňská, Prague 14021, Czech Republic
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Dezortova M, Herynek V, Krssak M, Kronerwetter C, Trattnig S, Hajek M. Two forms of iron as an intrinsic contrast agent in the basal ganglia of PKAN patients. CONTRAST MEDIA & MOLECULAR IMAGING 2013; 7:509-15. [PMID: 22991317 DOI: 10.1002/cmmi.1482] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
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.
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Affiliation(s)
- Monika Dezortova
- MR Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Prague, Czech Republic.
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Abstract
Magnetic resonance imaging (MRI) enables a noninvasive in vivo quantification of iron in various organs. Several techniques have been developed that detect signal alterations derived mainly from the magnetic properties of ferritin and hemosiderin, the major iron storage compounds. High magnetic susceptibility of ferritin shortens the transversal relaxation time of nearby water protons and thus induces a focal signal extinction of iron-rich areas in T2-weighted (T2w) MRI. T2w tissue contrast is additionally influenced by other factors such as water content, myelin density, and the presence of other metals. Therefore, more specific methods are needed with higher specificity to iron. These in vivo techniques can be divided into three groups: relaxometry, magnetic field correlation imaging and phase-based contrast covering susceptibility-weighted imaging, and quantitative susceptibility mapping. The differential diagnosis of various neurological disorders is aided by characteristic patterns of iron depositions. Reliable estimates of cerebral tissue iron concentration are equally important in studying physiological age-related as well as pathological conditions in neurodegenerative, neuroinflammatory, and vascular diseases. In the future, monitoring changes in iron storage and content may serve as sensitive biomarker for diagnosis as well as treatment monitoring.
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Affiliation(s)
- Petr Dusek
- Department of Neurology and Center of Clinical Neuroscience, Charles University in Prague, 1st Faculty of Medicine and General University Hospital, Prague, Czech Republic; Institut für interventionelle und diagnostische Neuroradiologie, Universitätsmedizin Göttingen, Göttingen, Germany.
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Quantitative MR imaging and spectroscopy of brain tumours: a step forward? Eur Radiol 2012; 22:2307-18. [PMID: 22688126 DOI: 10.1007/s00330-012-2502-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 04/09/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVES A prospective quantitative MR study of brain tumours was performed to show the potential of combining different MR techniques to distinguish various disease processes in routine clinical practice. METHODS Twenty-three patients with various intracranial tumours before treatment (diagnosis confirmed by a biopsy) and 59 healthy subjects were examined on a 3-T system by conventional MR imaging, 1H spectroscopic imaging, diffusion tensor imaging and T2 relaxometry. Metabolic concentrations and their ratios, T2 relaxation times and mean diffusivities were calculated and correlated on a pixel-by-pixel basis and compared to control data. RESULTS Different tumour types and different localisations revealed specific patterns of correlations between metabolic concentrations and mean diffusivity or T2 relaxation times. The patterns distinguish given tissue states in the examined area: healthy tissue, tissue infiltrated by tumour, active tumour, oedema infiltrated by tumour, oedema, etc. This method is able to describe the complexity of a highly heterogeneous tissue in the tumour and its vicinity, and determines crucial parameters for tissue differentiation. CONCLUSIONS A combination of different MR parameters on a pixel-by-pixel basis in individual patients enables better identification of the tumour type, direction of proliferation and assessment of the tumour extension. KEY POINTS • Magnetic resonance offers many different methods of examining the brain. • A combination of quantitative MR parameters helps distinguish different brain lesions • Different tumour types revealed specific correlation patterns amongst different MR parameters • The correlation patterns reflect highly heterogeneous complex tissue within tumours.
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