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Aim: To assess whether multimodal magnetic resonance imaging (MRI) could detect neuroanatomical substrates that are distinctive to hyposmic Parkinson's disease (PD)., Materials and Methods: Among 102 PD patients, 62 were hyposmic and 40 were normosmic. For each patient, a sagittal structural three-dimensional (3D) T1-weighted image was obtained with the magnetisation-prepared rapid acquisition of the gradient-echo sequence to generate subcortical grey matter masking templates and to perform a voxel-based morphometry analysis of the subcortical grey matter volumes. A 3D multi-echo gradient sequence was run to obtain axial magnitude and phase images to produce a quantitative susceptibility map (QSM), and a diffusion-weighted image was acquired to generate an apparent diffusion coefficient (ADC) map. The volumes and average QSM and ADC values of the 15 subcortical grey matter structures were calculated, and the group differences were evaluated using a one-way analysis of covariance with age and gender as covariates., Results: The QSM of the left thalamus significantly increased, while that of the right thalamus significantly decreased in hyposmia. No effects on the cortical volume changes were found other than aging., Conclusion: The present results suggest that accumulation of disease-related substances in the left and right thalamus and the increasing asymmetry between the two sides are associated with hyposmia in PD., (Copyright © 2019 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Aim: To describe characteristic magnetic resonance imaging (MRI) abnormalities in hyperglycaemia-induced seizures, and evaluate the diagnostic value of contrast-enhanced fluid-attenuated inversion recovery (FLAIR) imaging. Possible underlying mechanisms of this condition are also discussed., Materials and Methods: Eleven patients with hyperglycaemia-induced seizures and MRI abnormalities were retrospectively studied. Clinical manifestations, laboratory findings, MRI findings, and clinical outcomes were analysed., Results: All patients, except one, presented with focal seizures, simple or complex partial seizures, or negative motor seizures. All patients had long-standing uncontrolled diabetes mellitus. The MRI abnormalities observed acutely were focal subcortical hypointensities on T2-weighted imaging and FLAIR imaging in all patients with overlying cortical gyral T2 hyperintensities in five. Focal overlying cortical or leptomeningeal enhancement on contrast-enhanced T1-weighted imaging or contrast-enhanced FLAIR imaging was observed in all patients. Contrast-enhanced FLAIR imaging was superior to contrast-enhanced T1-weighted imaging for detecting characteristic cortical or leptomeningeal enhancement. Diffusion-weighted imaging showed mildly restricted diffusion in four of five patients with cortical gyral T2 hyperintensity. In nine patients, the lesions were localised in the parietal or parieto-occipital lobes. The other two patients showed localised precentral gyral lesions. After treatment, the neurological symptoms, including the seizures, improved in all patients. On clinical recovery, the subcortical T2 hypointensity, gyral or leptomeningeal enhancement, and overlying cortical T2 hyperintensities resolved., Conclusion: Recognition of these radiological abnormalities in patients with hyperglycaemia-induced seizures is important in restricting unwarranted investigations and initiating early therapy. These patients generally have a good prognosis., (Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Background and Purpose: BBB disruption after acute ischemic stroke and subsequent permeability increase may be enhanced by reperfusion. Agmatine has been reported to attenuate BBB disruption. Our aim was to evaluate the effects of agmatine on BBB stabilization in a rat model of transient cerebral ischemia by using permeability dynamic contrast-enhanced MR imaging at early stages and subsequently to demonstrate the feasibility of dynamic contrast-enhanced MR imaging for the investigation of new therapies., Materials and Methods: Thirty-four male Sprague-Dawley rats were subjected to transient MCA occlusion for 90 minutes. Immediately after reperfusion, agmatine (100 mg/kg) or normal saline was injected intraperitoneally into the agmatine-treated group (n = 17) or the control group, respectively. MR imaging was performed after reperfusion. For quantitative analysis, regions of interest were defined within the infarct area, and values for volume transfer constant, rate transfer coefficient, volume fraction of extravascular extracellular space, and volume fraction of blood plasma were obtained. Infarct volume, infarct growth, quantitative imaging parameters, and numbers of factor VIII-positive cells after immunohistochemical staining were compared between control and agmatine-treated groups., Results: Among the permeability parameters, volume transfer constant and volume fraction of extravascular extracellular space were significantly lower in the agmatine-treated group compared with the control group (0.05 ± 0.02 minutes(-1) versus 0.08 ± 0.03 minute(-1), P = .012, for volume transfer constant and 0.12 ± 0.06 versus 0.22 ± 0.15, P = .02 for volume fraction of extravascular extracellular space). Other permeability parameters were not significantly different between the groups. The number of factor VIII-positive cells was less in the agmatine-treated group than in the control group (3-fold versus 4-fold, P = .037)., Conclusions: In ischemic stroke, agmatine protects the BBB, which can be monitored in vivo by quantification of permeability by using dynamic contrast-enhanced MR imaging. Therefore, dynamic contrast-enhanced MR imaging may serve as a potential imaging biomarker for assessing the BBB stabilization properties of pharmacologic agents., (© 2015 by American Journal of Neuroradiology.)

Background: Acute inflammatory responses have been thought to play a central role in ischemia-reperfusion injury after acute ischemic stroke. Superparamagnetic iron oxide (SPIO) particles have been known to enable in-vivo monitoring of macrophage infiltration by magnetic resonance imaging (MRI) in the experimental ischemic rat brain., Purpose: To determine whether the accumulation of macrophages could be seen in vivo in a reperfusion animal model after focal cerebral ischemia using SPIO-enhanced MRI., Material and Methods: Thirty-four adult male rats were enrolled in this study. SPIO particles were injected into the rats at different time points after 1-hour transient occlusion of the middle cerebral artery, and three-dimensional (3D) T2*-weighted magnetic resonance (MR) images with a gradient-echo sequence were performed 24 hours later. Histochemical iron staining was compared with T2* signal abnormalities., Results: At days 3 and 4 post-reperfusion, focal areas of signal loss indicating local accumulation of SPIO particles appeared in a part of the damaged brain. Areas of signal loss corresponded to local accumulation of iron-laden macrophages in histologic sections, and SPIO-induced signal loss indicated active macrophage transmigration into the reperfused brain., Conclusion: SPIO-enhanced MRI demonstrated through in-vivo monitoring that macrophages participate in reperfusion injury at early stages of injury development. SPIO-enhanced MRI could be a useful tool to examine the inflammatory mechanisms involved in reperfusion brain injury.

Background and Purpose: The goal of thrombolytic therapy in patients with acute ischemic stroke is early recanalization, but this may result in delayed reperfusion injury. The purpose of this study was to evaluate the neuroprotective effect of agmatine in a transient ischemic cat model by using MR perfusion imaging and histopathologic analyses., Method: One-hour temporary occlusion of the left middle cerebral artery of cats was performed in the control ischemia group (n = 10), and 100 mg/kg of agmatine was intravenously injected immediately after recanalization in the agmatine-treated group (n = 15). MR imaging was performed at 1, 24, and 48 hours after recanalization, and the perfusion patterns were investigated. Terminal-deoxynucleotidyl transferase mediated nick and end-labeling (TUNEL) and hematoxylin-eosin (H&E) stainings were performed at the corresponding sections., Results: In the control ischemia group, the number of TUNEL-positive cells was significantly increased in the areas with reperfusion hyperemia (P < .05). In the agmatine-treated group, no significant increase in the number of TUNEL-positive cells was noted in the areas of reperfusion hyperemia. The difference in the number of TUNEL-positive cells between the control ischemia and agmatine-treated group in the areas of reperfusion hyperemia was significant (P < .05). The total number of TUNEL-positive cells and the area of severe ischemic neuronal damage on H&E stain were also significantly attenuated in the agmatine-treated cats compared with the control ischemia cats (P < .05)., Conclusion: Our results suggest that agmatine has neuroprotective effects against reperfusion injury and ischemia.

A number of segmentation algorithms have been developed, but those algorithms are not effective on volume reconstruction because they are limited to operating only on two-dimensional (2-D) images. In this paper, we propose the volumetric object reconstruction method using the three-dimensional Markov random field (3D-MRF) model-based segmentation. The 3D-MRF model is known to be one of efficient ways to model spatial contextual information. The method is compared with the 2-D region growing scheme under three types of interpolation. The results show that the proposed method is better in the aspect of image quality than other methods.

Background and purpose Elevated serum uric acid ( UA) is known to be associated with stroke. However, there is little information on the association between serum UA levels and cerebral microbleed ( CMB), a precursor of stroke. Therefore, we investigated the association between UA and CMB in a general population taking into consideration sex-related differences. Methods The subjects in this cross-sectional study consisted of 2686 individuals of 40-79 years of age (1403 men and 1283 women) who underwent regular health screenings, including brain magnetic resonance imaging, at Seoul National University Hospital Health Promotion Center. Subjects were categorized into three groups according to tertiles of UA levels by sex. The presence and location of CMB were assessed by gradient-recalled echo magnetic resonance imaging. Results The prevalence of CMB was 3.8%. In multivariate logistic regression analysis by sex, the highest tertile of UA in male subjects was independently associated with the presence of CMB compared with the lowest tertile of UA (adjusted odds ratio, 2.46; P = 0.013). Meanwhile, the highest tertile of UA in female subjects was inversely associated with CMB compared with the lowest tertile of UA (adjusted odds ratio, 0.39; P = 0.040). Conclusions High serum UA value was associated with higher prevalence of CMB in male, but lower prevalence of CMB in female subjects. [ABSTRACT FROM AUTHOR]

Background and purpose To evaluate whether white matter hyperintensities ( WMHs) may act as an independent predictor for progression of cognitive status, the authors analyzed the longitudinal effects of WMHs on cognitive dysfunction in non-demented patients with Parkinson's disease (PD). Methods A total of 111 patients with PD were enrolled, including subjects with mild cognitive impairment ( MCI, n = 65) and cognitively normal subjects ( CN, n = 46). These individuals were classified as MCI converters ( n = 22) or MCI non-converters ( n = 43) and CN converters ( n = 18) or CN non-converters ( n = 28) based on whether they were subsequently diagnosed with PD dementia or PD-MCI during a minimum 24-month follow-up. The WMH burden and the Cholinergic Pathway Hyperintensities Scale ( CHIPS) and their relationships to longitudinal changes in cognitive performance were examined. Results PD-MCI converters had larger WMH volume (14421.0 vs. 5180.4, P < 0.001) and higher CHIPS score (22.6 vs. 11.2, P = 0.001) compared with PD- MCI non-converters. Logistic regression analysis revealed in patients with PD- MCI that WMH volume (odds ratio 1.616, P = 0.009) and CHIPS score (odds ratio 1.084, P = 0.007) were independently associated with PD dementia conversion. However, WMH volume and CHIPS score did not differ between PD-CN converters and PD- CN non-converters. In patients with PD- MCI, both WMH volume and CHIPS score were closely associated with longitudinal decline in general cognition, semantic fluency and Stroop test scores. Conclusions The present study demonstrates that WMH burden is a significant predictor of conversion from PD-MCI to PD dementia and is related to ongoing decline in frontal-lobe-based cognitive performance. [ABSTRACT FROM AUTHOR]

Background: Probiotic treatment strategy based on the hygiene hypothesis, such as administration of ova from the non-pathogenic helminth, Trichuris suis, (TSO) has proven safe and effective in autoimmune inflammatory bowel disease. Objective: To study the safety and effects of TSO in a second autoimmune disease, multiple sclerosis (MS), we conducted the phase 1 Helminth-induced Immunomodulatory Therapy (HINT 1) study.Methods: Five subjects with newly diagnosed, treatment-naive relapsing–remitting multiple sclerosis (RRMS) were given 2500 TSO orally every 2 weeks for 3 months in a baseline versus treatment control exploratory trial.Results: The mean number of new gadolinium-enhancing magnetic resonance imaging (MRI) lesions (n-Gd+) fell from 6.6 at baseline to 2.0 at the end of TSO administration, and 2 months after TSO was discontinued, the mean number of n-Gd+ rose to 5.8. No significant adverse effects were observed. In preliminary immunological investigations, increases in the serum level of the cytokines IL-4 and IL-10 were noted in four of the five subjects. Conclusion: TSO was well tolerated in the first human study of this novel probiotic in RRMS, and favorable trends were observed in exploratory MRI and immunological assessments. Further investigations will be required to fully explore the safety, effects, and mechanism of action of this immunomodulatory treatment. [ABSTRACT FROM AUTHOR]