Imaging of remyelination

1997 ◽  
Vol 3 (2) ◽  
pp. 129-132 ◽  
Author(s):  
Frederik Barkhof
Keyword(s):  
Positron Emission Tomography ◽  
Animal Model ◽  
Magnetic Resonance ◽  
Spatial Resolution ◽  
Magnetization Transfer ◽  
Emission Tomography ◽  
Specific Magnetization ◽  
Magnetization Transfer Contrast ◽  
Positron Emission ◽  
Standard Techniques

Now that the concept of remyelination is gaining acceptance in MS, there is a need for a paraclinical marker to monitor remyelination in MS, for example to study the effect of therapeutical interventions. At present there is no known imaging marker for remyelination. While positron emission tomography (PET) has ample sensitivity and specificity, an appropriate tracer is lacking and spatial resolution is poor. Magnetic resonance (MR) imaging has superior sensitivity and spatial resolution, but the standard techniques lack specificity. Conventional T2-weighted images will most probably still appear abnormal in an area of remyelination. Among several newer MR techniques that are more specific, magnetization transfer contrast is the best candidate with regards to imaging remyelination. There is a strong need for an appropriate animal model and for histopathological confirmation to be able to further develop both PET and MR.

scholarly journals Observation of magnetic susceptibility changes within the thalamus: a comparative study between healthy and Parkinson’s disease afflicted cynomolgus monkeys using 7 T MRI

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sangwoo Kim ◽  
Youngjeon Lee ◽  
Chang-Yeop Jeon ◽  
Yeung Bae Jin ◽  
Sukhoon Oh ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Parkinson’S Disease ◽  
Positron Emission Tomography ◽  
Parkinson's Disease ◽  
Magnetic Resonance ◽  
Disease Model ◽  
Emission Tomography ◽  
Resonance Imaging ◽  
Cynomolgus Monkeys ◽  
Positron Emission

Abstract Background Although the thalamus is known to modulate basal ganglia function related to motor control activity, the abnormal changes within the thalamus during distinct medical complications have been scarcely investigated. In order to explore the feasibility of assessing iron accumulation in the thalamus as an informative biomarker for Parkinson’s disease (PD), this study was designed to employ quantitative susceptibility mapping using a 7 T magnetic resonance imaging system in cynomolgus monkeys. A 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-injected cynomolgus monkey and a healthy control (HC) were examined by 7 T magnetic resonance imaging. Positron emission tomography with 18F-N-(3-fluoro propyl)-2ß-carboxymethoxy-3ß-(4-iodophenyl) nortropane was also employed to identify the relationship between iron deposits and dopamine depletion. All acquired values were averaged within the volume of interest of the nigrostriatal pathway. Findings Compared with the HC, the overall elevation of iron deposition within the thalamus in the Parkinson’s disease model (about 53.81% increase) was similar to that in the substantia nigra (54.81%) region. Substantial susceptibility changes were observed in the intralaminar part of the thalamus (about 70.78% increase). Additionally, we observed that in the Parkinson’s disease model, binding potential values obtained from positron emission tomography were considerably decreased in the thalamus (97.51%) and substantia nigra (92.48%). Conclusions The increased iron deposition in the thalamus showed negative correlation with dopaminergic activity in PD, supporting the idea that iron accumulation affects glutaminergic inputs and dopaminergic neurons. This investigation indicates that the remarkable susceptibility changes in the thalamus could be an initial major diagnostic biomarker for Parkinson’s disease-related motor symptoms.

scholarly journals 18F-fluorodeoxyglucose positron emission tomography and magnetic resonance imaging evaluation of chorea

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Nobuyuki Ishii ◽  
Hitoshi Mochizuki ◽  
Miyuki Miyamoto ◽  
Yuka Ebihara ◽  
Kazutaka Shiomi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Positron Emission Tomography ◽  
Basal Ganglia ◽  
Magnetic Resonance ◽  
Emission Tomography ◽  
Fluorodeoxyglucose Positron Emission Tomography ◽  
Resonance Imaging ◽  
Indirect Pathway ◽  
Positron Emission ◽  
Fluorodeoxyglucose Positron Emission

Chorea is thought to be caused by deactivation of the indirect pathway in the basal ganglia circuit. However, few imaging studies have evaluated the basal ganglia circuit in actual patients with chorea. We investigated the lesions and mechanisms underlying chorea using brain magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). This retrospective case series included three patients with chorea caused by different diseases: hyperglycemic chorea, Huntington’s disease, and subarachnoid hemorrhage. All the patients showed dysfunction in the striatum detected by both MRI and FDG-PET. These neuroimaging findings confirm the theory that chorea is related to an impairment of the indirect pathway of basal ganglia circuit.

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