Magnetresonantstomograafiaga seotud riskid ja ohutuse tagamine

Magnetresonantstomograafia (MRT) on nüüdisaegne radioloogiline uurimismeetod, mis võimaldab kompuutertomograafiaga (KT) võrreldes paremini hinnata keha eri piirkondade pehmete kudede seisundit. Erinevalt KT- ja röntgenuuringutest ei kasutata MRTs patsienti kahjustavat ioniseerivat röntgenikiirgust. Kujutis patsiendi uuritavast piirkonnast luuakse mitteioniseeriva elektromagnetkiirguse abil. MRT-uuringute arv on aastate jooksul järjest suurenenud, kuna uurigu näidustusi on erialadel aina rohkem. Kui 2009. aastal tehti Tartu Ülikooli Kliinikumis MRT-uuringuid ca 6000 patsiendile, siis nüüdseks on see arv kasvanud 12 000-ni. Peale uuritavate arvu suurenemise on aja jooksul lisandunud üha keerulisemaid uuringuid (näiteks kardioloogia ja neuroloogia vallas), mida 10 aasta eest peaaegu ei tehtud ning mille tegemiseks kulub rohkem aega. Arvestades järjest suurenevat MRT-uuringute arvu, on oluline tähelepanu pöörata MRT-uuringuga kaasnevatele riskidele

Grey matter abnormalities in methcathinone abusers with a Parkinsonian syndrome

Funding Information: The study was supported by Grants GARNR9199 and GARLA0148P of the Estonian Science Foundation, and Grant No. 5.8.2 of the National Research Program of Latvia. Ricarda A L Menke is employed by the University of Oxford and her salary is funded by the Medical Research Council of the UK. Heidi Johansen-Berg is employed by the Universities of Oxford and Oslo, holds grants from the Wellcome Trust, National Institutes of Health Research, Education Endowment Foundation, Stroke Association, and Royalties from Elsevier. Charlotte J Stagg holds a Sir Henry Dale Fellowship jointly funded by the Wellcome Trust and the Royal Society. Ain?rs Stepens holds Grant No. 5.8.2 of the National Research Program of Latvia, which supported this study. Pille Taba holds Grant 9199 of the Estonian Science Foundation, which supported this study, is principal investigator of Grant 3.2.1001.11-0017 of the EU European Regional Development Fund, and participates in Grant IUT2-4 of the Estonian Research Council. Publisher Copyright: © 2016 The Authors. Brain and Behavior published by Wiley Periodicals, Inc. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.Background: A permanent Parkinsonian syndrome occurs in intravenous abusers of the designer psychostimulant methcathinone (ephedrone). It is attributed to deposition of contaminant manganese, as reflected by characteristic globus pallidus hyperintensity on T1-weighted MRI. Methods: We have investigated brain structure and function in methcathinone abusers (n = 12) compared to matched control subjects (n = 12) using T1-weighted structural and resting-state functional MRI. Results: Segmentation analysis revealed significant (p <.05) subcortical grey matter atrophy in methcathinone abusers within putamen and thalamus bilaterally, and the left caudate nucleus. The volume of the caudate nuclei correlated inversely with duration of methcathinone abuse. Voxel-based morphometry showed patients to have significant grey matter loss (p <.05) bilaterally in the putamina and caudate nucleus. Surface-based analysis demonstrated nine clusters of cerebral cortical thinning in methcathinone abusers, with relative sparing of prefrontal, parieto-occipital, and temporal regions. Resting-state functional MRI analysis showed increased functional connectivity within the motor network of patients (p <.05), particularly within the right primary motor cortex. Conclusion: Taken together, these results suggest that the manganese exposure associated with prolonged methcathinone abuse results in widespread structural and functional changes affecting both subcortical and cortical grey matter and their connections. Underlying the distinctive movement disorder caused by methcathinone abuse, there is a more widespread pattern of brain involvement than is evident from the hyperintensity restricted to the basal ganglia as shown by T1-weighted structural MRI.Peer reviewe

Cubic Iron Core–Shell Nanoparticles Functionalized to Obtain High-Performance MRI Contrast Agents

Nanoparticles with SiO2 coating were synthesized to have a cubic iron core. These were found to have saturation magnetization very close to the highest possible value of any iron-containing nanoparticles and the bulk iron saturation magnetization. The in vitro toxicology studies show that they are highly biocompatible and possess better MRI contrast agent potential than iron oxide NPs