Purpose
The authors analyzed the characteristics of perfusion magnetic resonance imaging (MRI), 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and 11C-methionine (MET) PET to compare the efficacies of these modalities in making the distinction between radiation necrosis and tumor recurrence of high-grade glioma.Patients and methods
Ten patients were evaluated with dynamic susceptibility contrast perfusion MRI, 11C-MET PET and 18F-FDG PET to visualize gadolinium-enhanced lesions during the post-radiation follow-up period. In the perfusion MRI, four regions of interest (ROIs) were identified and average values were calculated. A reference ROI of the same size was defined in the contralateral white matter to obtain the relative cerebral blood volume (rCBV). After coregistering the PET images with the MRI, we measured the maximum uptake values of the lesion and of the contralateral cerebral white matter as reference area to calculate the Lmax/Rmax ratio.Results
The rCBV was higher in the recurrence group than in the necrosis group (p = 0.010). There was no difference between groups in terms of the Lmax/Rmax ratio as derived from the 18F-FDG and 11C-MET PET.Conclusion
A quantitative rCBV as calculated from a perfusion MRI scan might be superior to the Lmax/Rmax ratio as derived from 18F-FDG and 11C-MET PET in order to distinguish a recurrence of high-grade glioma from radiation necrosis. 相似文献Background and purpose
This study was aimed to assess the hypothesis that unstable plaque formation in the carotid artery is one of phenotypes of chronic and systemic inflammation.Methods
This study included 8 symptomatic patients with internal carotid stenosis (ICS) and 7 healthy controls. All subjects underwent 18F-fluorodeoxyglucos positron emission tomography (18F-FDG PET) of whole body. Plaque vulnerability was evaluated on magnetic resonance imaging (MRI). On 18F-FDG PET, the maximum standardized uptake (SUVmax) value was measured in the carotid plaque, aorta, spleen, liver, and bone marrow. The SUVmax ratio of the spleen or bone marrow to the liver was also calculated. These values were compared between 2 groups. All 8 patients in ICS group underwent carotid endarterectomy, and surgical specimens were subjected to immunohistochemistry.Results
All 8 patients in ICS group had unstable plaque on MRI. The mean SUVmax of carotid plaque was 2.5 ± .2 in ICS group. The SUVmax of spleen was significantly higher in ICS group than in the controls (3.20 ± ?.25 and 2.51 ± ?.40, respectively; P?=?.003). The SUVmax ratio (spleen/liver) was also significantly higher in ICS group than in the controls (1.12 ± ?.06 and .85 ± ?.12, respectively; P?=?.001). The SUVmax of aorta was also significantly higher in ICS group than in the controls (2.16 ± ?.27 and 1.48 ± ?.15, respectively; P?=?.001). However, there were no significant differences in the SUVmax in the bone marrow and SUVmax ratio (bone marrow/liver) between the 2 groups (P?=?.811 and P?=?.731, respectively). Histological examination showed that the plaque strongly expressed endothelial progenitor cells, microvessels, and M1 macrophages.Conclusions
These data strongly suggest the inflammation coupling between the spleen and unstable carotid plaque, and may be useful to develop novel therapeutic strategies against systemic inflammation in patients with ICS. 相似文献Objective
Favorable seizure outcome is reported following resection of bottom-of-sulcus dysplasia (BOSD). We assessed the distribution of epileptogenicity and dysplasia in and around BOSD to better understand this clinical outcome and the optimal surgical approach.Methods
We studied 27 children and adolescents with magnetic resonance imaging (MRI)-positive BOSD who underwent epilepsy surgery; 85% became seizure-free postresection (median = 5.0 years follow-up). All patients had resection of the dysplastic sulcus, and 11 had additional resection of the gyral crown (GC) or adjacent gyri (AG). Markers of epileptogenicity were relative cortical hypometabolism on preoperative 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET), and spiking, ripples, fast ripples, spike–high-frequency oscillation cross-rate, and phase amplitude coupling (PAC) on preresection and postresection electrocorticography (ECoG), all analyzed at the bottom-of-sulcus (BOS), top-of-sulcus (TOS), GC, and AG. Markers of dysplasia were increased cortical thickness on preoperative MRI, and dysmorphic neuron density and variant allele frequency of somatic MTOR mutations in resected tissue, analyzed at similar locations.Results
Relative cortical metabolism was significantly reduced and ECoG markers were significantly increased at the BOS compared to other regions. Apart from spiking and PAC, which were greater at the TOS compared to the GC, there were no significant differences in PET and other ECoG markers between the TOS, GC, and AG, suggesting a cutoff of epileptogenicity at the TOS rather than a tapering gradient on the cortical surface. MRI and tissue markers of dysplasia were all maximal in the BOS, reduced in the TOS, and mostly absent in the GC. Spiking and PAC reduced significantly over the GC after resection of the dysplastic sulcus.Significance
These findings support the concept that dysplasia and intrinsic epileptogenicity are mostly limited to the dysplastic sulcus in BOSD and support resection or ablation confined to the MRI-visible lesion as a first-line surgical approach. 18F-FDG PET and ECoG abnormalities in surrounding cortex seem to be secondary phenomena. 相似文献Background
Synaptic loss is characteristic of many neurodegenerative diseases; it occurs early and is strongly related to functional deficits.Objective
In this longitudinal observational study, we determine the rate at which synaptic density is reduced in the primary tauopathies of progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD), and we test the relationship with disease progression.Methods
Our cross-sectional cohort included 32 participants with probable PSP and 16 with probable CBD (all amyloid-negative corticobasal syndrome), recruited from tertiary care centers in the United Kingdom, and 33 sex- and age-matched healthy control subjects. Synaptic density was estimated by positron emission tomography imaging with the radioligand [11C]UCB-J that binds synaptic vesicle 2A. Clinical severity and cognition were assessed by the PSP Rating Scale and the Addenbrooke's cognitive examination. Regional [11C]UCB-J nondisplaceable binding potential was estimated in Hammersmith Atlas regions of interest. Twenty-two participants with PSP/CBD had a follow-up [11C]UCB-J positron emission tomography scan after 1 year. We calculated the annualized change in [11C]UCB-J nondisplaceable binding potential and correlated this with the change in clinical severity.Results
We found significant annual synaptic loss within the frontal lobe (−3.5%, P = 0.03) and the right caudate (−3.9%, P = 0.046). The degree of longitudinal synaptic loss within the frontal lobe correlated with the rate of change in the PSP Rating Scale (R = 0.47, P = 0.03) and cognition (Addenbrooke's Cognitive Examination–Revised, R = −0.62, P = 0.003).Conclusions
We provide in vivo evidence for rapid progressive synaptic loss, correlating with clinical progression in primary tauopathies. Synaptic loss may be an important therapeutic target and outcome variable for early-phase clinical trials of disease-modifying treatments. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. 相似文献Introduction
The relative importance of structural magnetic resonance imaging (MRI) and tau positron emission tomography (PET) to predict diagnosis and cognition in Alzheimer's disease (AD) is unclear.Methods
We tested 56 cognitively unimpaired controls (including 27 preclinical AD), 32 patients with prodromal AD, and 39 patients with AD dementia. Optimal classifiers were constructed using the least absolute shrinkage and selection operator with 18F-AV-1451 (tau) PET and structural MRI data (regional cortical thickness and subcortical volumes).Results
18F-AV-1451 in the amygdala, entorhinal cortex, parahippocampal gyrus, fusiform, and inferior parietal lobule had 93% diagnostic accuracy for AD (prodromal or dementia). The MRI classifier involved partly the same regions plus the hippocampus, with 83% accuracy, but did not improve upon the tau classifier. 18F-AV-1451 retention and MRI were independently associated with cognition.Discussion
Optimized tau PET classifiers may diagnose AD with high accuracy, but both tau PET and structural brain MRI capture partly unique information relevant for the clinical deterioration in AD. 相似文献Methods: We used middle cerebral artery occlusion (MCAO) procedure to induce cerebral ischemia in rats. Male rats were divided into a negative control group (Normal, n = 4), a sham-operated group (Sham, n = 6), an ischemic group (Control, n = 6) and an ischemic CIMT-treated group (CIMT, n = 6). CIMT started at postoperative day 8 (d8) and lasted for 2 weeks. We utilized 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) micro PET/CT imaging to evaluate glucose metabolism in different brain regions at baseline, before, and after treatment, respectively.
Results: CIMT improved behavioral performance in the ischemic CIMT group. At the end of treatment, the CIMT group showed lower standardized uptake values (SUVs) in the ipsilateral cingulate, motor and somatosensory cortex, respectively; as well as the anterodorsal hippocampus compared to the Control group (1.80% ± 0.10% vs. 1.92% ± 0.08%, 1.32% ± 0.14% vs. 1.48% ± 0.09%, 1.18% ± 0.14% vs. 1.42% ± 0.15%, 1.68% ± 0.09% vs. 1.79% ± 0.06%, P < 0.05). We also observed higher SUVs in the acbcore shell and cortex insular of the contralateral hemisphere compared to the Control group (2.07% group in the acbcore shell and cortex insular of contralateral P < 0.05).
Conclusion: CIMT improved behavioral outcomes in cerebral ischemic rats and this effect can be attributed to increased glucose utilization in the contralateral hemisphere. 相似文献
Background and purpose
The presence of apolipoprotein E ε4 (APOE ε4) is associated with an increased risk of developing Alzheimer disease (AD). The aim of this study was to assess the effects of APOE ε4 on amyloid-β (Aβ) pathology, glucose metabolism, and gray matter (GM) volume and their longitudinal changes in healthy control (HC) and amnestic mild cognitive impairment (aMCI).Methods
We included 50 HCs and 109 aMCI patients from the Alzheimer's Disease Neuroimaging Initiative phase 2/GO based on availability of baseline T1-weighted magnetic resonance imaging, 18F-florbetapir positron emission tomography (PET), and 18F-fluorodeoxyglucose (FDG) PET. Of these, 35 HCs and 67 aMCI patients who underwent 24-month scans were included for follow-up study.Results
Voxelwise analysis revealed that APOE ε4 carriers exhibited greater baseline Aβ deposition than APOE ε4 noncarriers in both diagnostic groups. However, there was no significant difference between APOE ε4 noncarriers and APOE ε4 carriers in terms of 18F-FDG PET standardized uptake value ratio and GM volume. Region of interest-based analysis showed statistically significant greater Aβ deposition in APOE ε4 carriers than APOE ε4 noncarriers only in aMCI patients. Furthermore, APOE ε4 carriers generally exhibited a greater magnitude and spatial extent of longitudinal changes in Aβ deposition than APOE ε4 noncarriers in both diagnostic groups.Conclusions
Our findings suggest a differential effect of APOE ε4 on Aβ pathology, glucose metabolism, and GM volume. Studying APOE ε4-related brain changes with neuroimaging biomarkers in preclinical AD offers an opportunity to further our understanding of the pathophysiology of AD at an early stage. 相似文献Background
Methods to study gastric emptying in rodents are time consuming or terminal, preventing repetitive assessment in the same animal. Magnetic resonance imaging (MRI) is a non-invasive technique increasingly used to investigate gastrointestinal function devoid of these shortcomings. Here, we evaluated MRI to measure gastric emptying in control animals and in two different models of gastroparesis.Methods
Mice were scanned using a 9.4 Tesla MR scanner. Gastric volume was measured by delineating the stomach lumen area. Control mice were scanned every 30 min after ingestion of a 0.2 g meal and stomach volume was quantified. The ability of MRI to detect delayed gastric emptying was evaluated in models of morphine-induced gastroparesis and streptozotocin-induced diabetes.Key Results
Magnetic resonance imaging reproducibly detected increased gastric volume following ingestion of a standard meal and progressively decreased with a half emptying time of 59 ± 5 min. Morphine significantly increased gastric volume measured at t = 120 min (saline: 20 ± 2 vs morphine: 34 ± 5 mm3; n = 8–10; p < 0.001) and increased half emptying time using the breath test (saline: 85 ± 22 vs morphine: 161 ± 46 min; n = 10; p < 0.001). In diabetic mice, gastric volume assessed by MRI at t = 60 min (control: 23 ± 2 mm3; n = 14 vs diabetic: 26 ± 5 mm3; n = 18; p = 0.014) but not at t = 120 min (control: 21 ± 3 mm3; n = 13 vs diabetic: 18 ± 5 mm3; n = 18; p = 0.115) was significantly increased compared to nondiabetic mice.Conclusions and Inferences
Our data indicate that MRI is a reliable and reproducible tool to assess gastric emptying in mice and represents a useful technique to study gastroparesis in disease models or for evaluation of pharmacological compounds. 相似文献Methods: 78 healthy right-handed Chinese volunteers from Tangdu Hospital were scanned using 18F-FDG PET to evaluate brain metabolism between March and October 2016. All PET images were processed using MIMneuro software to create a normal database platform. The platform included anatomical optimization to facilitate spatial localization of abnormalities and a statistical comparison with normal cases utilizing the Z-scores, which represent the number of standard deviations from the mean of the normal controls in the database.
Results: The novel Chinese brain metabolism database platform including 78 healthy volunteers (male: female 40:38; age 3–78 years, mean age, 45 years) was constructed based on the MIMneuro software, which increased the diagnostic confidence in the test patient by quantifying and emphasizing the abnormality. The BrainAlignTM deformation algorithm of MIMneuro matched the size, shape, and orientation of the patient's brain scan to a template brain for comparison against a database of normal controls. The quantitative analysis performed on a voxel and regional level was useful in assessing the areas of abnormalities.
Conclusions: A novel Chinese 18F-FDG PET-based normal brain function database was created to highlight the local regions of abnormal metabolic activity through quantitative comparisons against the normal database. The Z-scores obtained by MIMneuro potentially aid in visualizing and quantifying the subtle lesions on 18FDG-PET scan images as observed in a patient diagnosed with epilepsy. 相似文献
Background
Patients with Lewy body diseases exhibit variable degrees of cortical and subcortical hypometabolism. However, the underlying causes behind this progressive hypometabolism remain unresolved. Generalized synaptic degeneration may be one key contributor.Objective
The objective of this study was to investigate whether local cortical synaptic loss is proportionally linked to the magnitude of hypometabolism in Lewy body disease.Method
Using in vivo positron emission tomography (PET) we investigated cerebral glucose metabolism and quantified the density of cerebral synapses, as measured with [18F]fluorodeoxyglucose ([18F]FDG) PET and [11C]UCB-J, respectively. Volumes-of-interest were defined on magnetic resonance T1 scans and regional standard uptake value ratios-1 values were obtained for 14 pre-selected brain regions. Between-group comparisons were conducted at voxel-level.Results
We observed regional differences in both synaptic density and cerebral glucose consumption in our cohorts of non-demented and demented patients with Parkinson's disease or dementia with Lewy bodies compared to healthy subjects. Additionally, voxel-wise comparisons showed a clear difference in cortical regions between demented patients and controls for both tracers. Importantly, our findings strongly suggested that the magnitude of reduced glucose uptake exceeded the magnitude of reduced cortical synaptic density.Conclusion
Here, we investigated the relationship between in vivo glucose uptake and the magnitude of synaptic density as measured using [18F]FDG PET and [11C]UCB-J PET in Lewy body patients. The magnitude of reduced [18F]FDG uptake was greater than the corresponding decline in [11C]UCB-J binding. Therefore, the progressive hypometabolism seen in Lewy body disorders cannot be fully explained by generalized synaptic degeneration. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. 相似文献Background
Bipolar disorder (BD) is a common mental disorder, subdivided into BD-I and BD-II. Currently, few biomarkers differentiate BD-I from BD-II. However, it is suggested that peripheral blood mononuclear cell (PBMC) mRNA levels of p11 and positron emission tomography (PET) might be potential biomarkers for BD.Methods
Healthy controls (HCs), BD-I, and BD-II patients in remission (n = 20 in each group) underwent a resting PET study with the radiotracer [18F]-2-deoxy-2-fluoro-d-glucose (18F-FDG). PBMC p11 mRNA levels were determined by quantitative real-time PCR.Results
Comparing BD patients to HCs, normalized glucose metabolism (NGM) was higher in the hippocampus, parahippocampus, and amygdala, but lower in the anterior cingulate cortex (aCC), medial prefrontal cortex (mPFC), dorsolateral prefrontal cortex (dlPFC), insula and thalamus. Compared to BD-II, BD-I had hypometabolism of glucose in the aCC, bilateral middle and inferior gyrus, insula and striatum, and hypermetabolism of glucose in the left parahippocampus. PBMC p11 mRNA was over-expressed in both BD-I and BD-II, although there was no significant difference in its expression levels between BD-I and B-II patients. Further, there were significant positive correlations between PBMC p11 mRNA and NGM in the mPFC, aCC, left insula, bilateral orbitofrontal cortex (OFC), and left middle, inferior and superior temporal gyri. Also, PBMC p11 mRNA was positively correlated to the number of depressive episodes in BD patients, especially in BD-I patients.Discussion
This study demonstrates that PBMC p11 mRNA expression is associated with neural activation in the brain of BD patients and warrants a larger translational study to determine its clinical utility. 相似文献![点击此处可从《Journal of neuroimaging》网站下载免费的PDF全文](/ch/ext_images/free.gif)