scholarly journals Reproducible Analysis of Rat Brain PET Studies Using an Additional [18F]NaF Scan and an MR-Based ROI Template

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Hans J. C. Buiter ◽  
Floris H. P. van Velden ◽  
Josée E. Leysen ◽  
Abraham Fisher ◽  
Albert D. Windhorst ◽  
...  
Keyword(s):  
Rat Brain ◽  
Ex Vivo ◽  
Correlation Coefficients ◽  
Brain Regions ◽  
Image Coregistration ◽  
Brain Pet ◽  
Biodistribution Data ◽  
Positron Emission ◽  
Reproducible Analysis ◽  
Uptake Data

Background. An important step in the analysis of positron emission tomography (PET) studies of the brain is the definition of regions of interest (ROI). Image coregistration, ROI analysis, and quantification of brain PET data in small animals can be observer dependent. The purpose of this study was to investigate the feasibility of ROI analysis based on a standard MR template and an additional [18F]NaF scan. Methods. [18F]NaF scans of 10 Wistar rats were coregistered with a standard MR template by 3 observers and derived transformation matrices were applied to corresponding [11C]AF150(S) images. Uptake measures were derived for several brain regions delineated using the MR template. Overall agreement between the 3 observers was assessed by interclass correlation coefficients (ICC) of uptake data. In addition, [11C]AF150(S) ROI data were compared with ex vivo biodistribution data. Results. For all brain regions, ICC analysis showed excellent agreement between observers. Reproducibility, estimated by calculation of standard deviation of the between-observer differences, was demonstrated by an average of 17% expressed as coefficient of variation. Uptake of [11C]AF150(S) derived from ROI analysis closely matched ex vivo biodistribution data. Conclusions. The proposed method provides a reproducible and tracer-independent method for ROI analysis of rat brain PET data.

scholarly journals Population-specific brain [18F]-FDG PET templates of Chinese subjects for statistical parametric mapping

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Hongkai Wang ◽  
Yang Tian ◽  
Yang Liu ◽  
Zhaofeng Chen ◽  
Haoyu Zhai ◽  
...  
Keyword(s):  
Fdg Pet ◽  
Statistical Parametric Mapping ◽  
Brain Regions ◽  
Brain Images ◽  
Parametric Mapping ◽  
Brain Morphometry ◽  
Brain Pet ◽  
Positron Emission ◽  
The Family ◽  
Function Impairment

AbstractStatistical Parametric Mapping (SPM) is a computational approach for analysing functional brain images like Positron Emission Tomography (PET). When performing SPM analysis for different patient populations, brain PET template images representing population-specific brain morphometry and metabolism features are helpful. However, most currently available brain PET templates were constructed using the Caucasian data. To enrich the family of publicly available brain PET templates, we created Chinese-specific template images based on 116 [18F]-fluorodeoxyglucose ([18F]-FDG) PET images of normal participants. These images were warped into a common averaged space, in which the mean and standard deviation templates were both computed. We also developed the SPM analysis programmes to facilitate easy use of the templates. Our templates were validated through the SPM analysis of Alzheimer’s and Parkinson’s patient images. The resultant SPM t-maps accurately depicted the disease-related brain regions with abnormal [18F]-FDG uptake, proving the templates’ effectiveness in brain function impairment analysis.

scholarly journals Regional Cerebral l-[14C-Methyl]Methionine Incorporation into Proteins: Evidence for Methionine Recycling in the Rat Brain

1992 ◽  
Vol 12 (4) ◽  
pp. 603-612 ◽  
Author(s):  
Anna M. Planas ◽  
Christian Prenant ◽  
Bernard M. Mazoyer ◽  
Dominique Comar ◽  
Luigi Di Giamberardino
Keyword(s):  
Rat Brain ◽  
Specific Activity ◽  
Plasma Source ◽  
Brain Regions ◽  
Emission Tomography ◽  
Protein Breakdown ◽  
Isotopic Equilibrium ◽  
Positron Emission ◽  
Time Periods ◽  
The Brain

The specific activity (SA) of free methionine was measured in plasma and in different regions of the rat brain at 15, 30, or 60 min after intravenous infusion of l-[14C- methyl]methionine. Within these time periods, an apparent steady state of labeled free methionine in plasma and in brain was reached. However, the brain-to-plasma free methionine SA ratio was found to be ∼0.5, showing that an isotopic equilibrium between brain and plasma was not attained. This suggests the presence of an endogenous source of brain free methionine (likely originating from protein breakdown), in addition to the plasma source. The contribution of this endogenous source to the content of free methionine varies significantly among the different brain regions. Our results indicate that the regional rates of protein synthesis measured with l-[11C- methyl]methionine using positron emission tomography would be underestimated, since the local fraction of brain methionine derived from protein degradation would not be considered.

scholarly journals Inhibition of fatty acid amide hydrolase by BIA 10-2474 in rat brain

2016 ◽  
Vol 37 (11) ◽  
pp. 3635-3639 ◽  
Author(s):  
Junchao Tong ◽  
Romina Mizrahi ◽  
Sylvain Houle ◽  
Stephen J Kish ◽  
Isabelle Boileau ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Rat Brain ◽  
Fatty Acid Amide Hydrolase ◽  
Ex Vivo ◽  
Acid Amide ◽  
Brain Regions ◽  
Recent Clinical Trial ◽  
The Central Nervous System ◽  
Amide Hydrolase ◽  
Fatty Acid Amide

In a recent clinical trial, the drug BIA 10-2474, a putative fatty acid amide hydrolase(FAAH) inhibitor, was responsible for severe adverse events (SAEs), including one death. To date, there has been little reliable information divulged about the potency of BIA 10-2474 at FAAH in the central nervous system. We synthesised BIA 10-2474 and determined its ability to inhibit FAAH ex vivo in rat brain using a FAAH selective radiotracer. BIA 10-2474 proved to be a potent FAAH inhibitor with IC50s of 50–70 µg/kg (i.p.) in various brain regions. This information may be useful for determining the cause of the SAEs.

scholarly journals Detection of Remote Neuronal Reactions in the Thalamus and Hippocampus Induced by Rat Glioma Using the PET Tracer Cis-4-[18F]Fluoro-D-Proline

2013 ◽  
Vol 33 (5) ◽  
pp. 724-731 ◽  
Author(s):  
Stefanie Geisler ◽  
Antje Willuweit ◽  
Michael Schroeter ◽  
Karl Zilles ◽  
Kurt Hamacher ◽  
...  
Keyword(s):  
Ex Vivo ◽  
High Sensitivity ◽  
Brain Regions ◽  
Tracer Uptake ◽  
Thalamic Nuclei ◽  
Brain Areas ◽  
Rat Glioma ◽  
F98 Rat Glioma ◽  
Pet Tracer ◽  
Positron Emission

After cerebral ischemia or trauma, secondary neurodegeneration may occur in brain regions remote from the lesion. Little is known about the capacity of cerebral gliomas to induce secondary neurodegeneration. A previous study showed that cis-4-[18F]fluoro-D-proline (D- cis-[18F]FPro) detects secondary reactions of thalamic nuclei after cortical infarction with high sensitivity. Here we investigated the potential of D- cis-[18F]FPro to detect neuronal reactions in remote brain areas in the F98 rat glioma model using ex vivo autoradiography. Although the tumor tissue of F98 gliomas showed no significant D- cis-[18F]FPro uptake, we observed prominent tracer uptake in 7 of 10 animals in the nuclei of the ipsilateral thalamus, which varied with the specific connectivity with the cortical areas affected by the tumor. In addition, strong D- cis-[18F]FPro accumulation was noted in the hippocampal area CA1 in two animals with ipsilateral F98 gliomas involving hippocampal subarea CA3 rostral to that area. Furthermore, focal D- cis-[18F]FPro uptake was present in the necrotic center of the tumors. Cis-4-[18F]fluoro-D-proline uptake was accompanied by microglial activation in the thalamus, in the hippocampus, and in the necrotic center of the tumors. The data suggest that brain tumors induce secondary neuronal reactions in remote brain areas, which may be detected by positron emission tomography (PET) using D- cis-[18F]FPro.

scholarly journals Ratlas-LH: An MRI template of the Lister hooded rat brain with stereotaxic coordinates for neurosurgical implantations

2021 ◽  
Vol 5 ◽  
pp. 239821282110363
Author(s):  
Malcolm J. W. Prior ◽  
Tobias Bast ◽  
Stephanie McGarrity ◽  
Jürgen Goldschmidt ◽  
Daniel Vincenz ◽  
...  
Keyword(s):  
Rat Brain ◽  
Ex Vivo ◽  
Brain Regions ◽  
Magnetic Resonance Images ◽  
Brain Atlas ◽  
Neurosurgical Procedures ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Computed Tomography Images

There is currently no brain atlas available to specifically determine stereotaxic coordinates for neurosurgery in Lister hooded rats despite the popularity of this strain for behavioural neuroscience studies in the United Kingdom and elsewhere. We have created a dataset, which we refer to as ‘Ratlas-LH’ (for Lister hooded). Ratlas-LH combines in vivo magnetic resonance images of the brain of young adult male Lister hooded rats with ex vivo micro-computed tomography images of the ex vivo skull, as well as a set of delineations of brain regions, adapted from the Waxholm Space Atlas of the Sprague Dawley Rat Brain. Ratlas-LH was produced with an isotropic resolution of 0.15 mm. It has been labelled in such a way as to provide a stereotaxic coordinate system for the determination of distances relative to the skull landmark of bregma. We have demonstrated that the atlas can be used to determine stereotaxic coordinates to accurately target brain regions in the Lister hooded rat brain. Ratlas-LH is freely available to facilitate neurosurgical procedures in the Lister hooded rat.

Monitoring Heparin Therapy: Relationships between the Activated Partial Thromboplastin Time and Heparin Assays Based on Ex-Vivo Heparin Samples

1990 ◽  
Vol 63 (01) ◽  
pp. 016-023 ◽  
Author(s):  
A M H P van den Bessekaar ◽  
J Meeuwisse-Braun ◽  
R M Bertina
Keyword(s):  
Partial Thromboplastin Time ◽  
Plasma Sample ◽  
Ex Vivo ◽  
Correlation Coefficients ◽  
Heparin Therapy ◽  
Thromboembolic Disease ◽  
Activated Partial Thromboplastin Time ◽  
Venous Thromboembolic Disease ◽  
Venous Thromboembolic

SummaryFive different APTT reagents, two amidolytic anti-ITa assays, one amidoiytic anti-Xa assay, and one coagulometric anti-Xa/ anti-IIa assay were used to assess the effect of heparin in patients treated for venous thromboembolic disease. Good correlations were observed between lug-transformed APYE> determined with the various reagents (correlation coefficients: 0.92-0.96).Nevertheless there were important differences in the slopes of the lines of relationship between the APTT reagents.Good correlations were observed between the anti-Xa and anti-IIa assay results (correlation coefficients: 0.92-0.97). However, the amidolytic anti-Xa activity was significantly higher (p <0.001) than the two amidolytic anti-IIa activities. Less good correlations were observed between the log-transformed APTTs and the anti-Xa or anti-IIa activities (correlation coefficients: 0.64-0.78). The correlations were improved by transforming the APTT into APTT-ratio, i.e. the ratio of the patient’s APTT to the same patient’s APTT after removal of heparin from the plasma sample by means of ECTEOLA-cellulose treatment. The correlation coefficients of log (AFTT-ratio) with anti-Xa or anti-IIa ranged from 0.76 to 0.87.For both APTT and amidolytic heparin assay, the response to in vitro heparin was different from the response to ex vivo heparin.Therefore, equivalent therapeutic ranges should be assessed by using ex vivo samples rather than in vitro heparin. Because of the response differences between the APTT reagents, it is not adequate to define a therapeutic range for heparin therapy without specification of the reagent.

scholarly journals Accurate Transmission-Less Attenuation Correction Method for Amyloid-β Brain PET Using Deep Neural Network

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1836
Author(s):  
Bo-Hye Choi ◽  
Donghwi Hwang ◽  
Seung-Kwan Kang ◽  
Kyeong-Yun Kim ◽  
Hongyoon Choi ◽  
...  
Keyword(s):  
Neural Network ◽  
Attenuation Correction ◽  
Complex Structure ◽  
Scatter Correction ◽  
Amyloid Β ◽  
Correction Method ◽  
Percentage Error ◽  
Similarity Coefficients ◽  
Brain Pet ◽  
Positron Emission

The lack of physically measured attenuation maps (μ-maps) for attenuation and scatter correction is an important technical challenge in brain-dedicated stand-alone positron emission tomography (PET) scanners. The accuracy of the calculated attenuation correction is limited by the nonuniformity of tissue composition due to pathologic conditions and the complex structure of facial bones. The aim of this study is to develop an accurate transmission-less attenuation correction method for amyloid-β (Aβ) brain PET studies. We investigated the validity of a deep convolutional neural network trained to produce a CT-derived μ-map (μ-CT) from simultaneously reconstructed activity and attenuation maps using the MLAA (maximum likelihood reconstruction of activity and attenuation) algorithm for Aβ brain PET. The performance of three different structures of U-net models (2D, 2.5D, and 3D) were compared. The U-net models generated less noisy and more uniform μ-maps than MLAA μ-maps. Among the three different U-net models, the patch-based 3D U-net model reduced noise and cross-talk artifacts more effectively. The Dice similarity coefficients between the μ-map generated using 3D U-net and μ-CT in bone and air segments were 0.83 and 0.67. All three U-net models showed better voxel-wise correlation of the μ-maps compared to MLAA. The patch-based 3D U-net model was the best. While the uptake value of MLAA yielded a high percentage error of 20% or more, the uptake value of 3D U-nets yielded the lowest percentage error within 5%. The proposed deep learning approach that requires no transmission data, anatomic image, or atlas/template for PET attenuation correction remarkably enhanced the quantitative accuracy of the simultaneously estimated MLAA μ-maps from Aβ brain PET.

scholarly journals Disrupted metabolic connectivity in dopaminergic and cholinergic networks at different stages of dementia from 18F-FDG PET brain persistent homology network

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tun-Wei Hsu ◽  
Jong-Ling Fuh ◽  
Da-Wei Wang ◽  
Li-Fen Chen ◽  
Chia-Jung Chang ◽  
...  
Keyword(s):  
Algebraic Topology ◽  
Fdg Pet ◽  
Persistent Homology ◽  
Network Connectivity ◽  
Brain Regions ◽  
Imaging Data ◽  
Cholinergic Pathways ◽  
Positron Emission ◽  
Metabolic Connectivity ◽  
Neurochemical Changes

AbstractDementia is related to the cellular accumulation of β-amyloid plaques, tau aggregates, or α-synuclein aggregates, or to neurotransmitter deficiencies in the dopaminergic and cholinergic pathways. Cellular and neurochemical changes are both involved in dementia pathology. However, the role of dopaminergic and cholinergic networks in metabolic connectivity at different stages of dementia remains unclear. The altered network organisation of the human brain characteristic of many neuropsychiatric and neurodegenerative disorders can be detected using persistent homology network (PHN) analysis and algebraic topology. We used 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging data to construct dopaminergic and cholinergic metabolism networks, and used PHN analysis to track the evolution of these networks in patients with different stages of dementia. The sums of the network distances revealed significant differences between the network connectivity evident in the Alzheimer’s disease and mild cognitive impairment cohorts. A larger distance between brain regions can indicate poorer efficiency in the integration of information. PHN analysis revealed the structural properties of and changes in the dopaminergic and cholinergic metabolism networks in patients with different stages of dementia at a range of thresholds. This method was thus able to identify dysregulation of dopaminergic and cholinergic networks in the pathology of dementia.

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