scholarly journals The choice of embedding media affects image quality, tissue R 2 * , and susceptibility behaviors in post‐mortem brain MR microscopy at 7.0T

2018 ◽  
Vol 81 (4) ◽  
pp. 2688-2701 ◽  
Author(s):  
Petr Dusek ◽  
Vince Istvan Madai ◽  
Till Huelnhagen ◽  
Erik Bahn ◽  
Radoslav Matej ◽  
...  
Keyword(s):  
Image Quality ◽  
Post Mortem ◽  
Mr Microscopy ◽  
Post Mortem Brain

scholarly journals Threshold-dependent iodine imaging and spectral separation in a whole-body photon-counting CT system

2021 ◽  
Author(s):  
S. Sawall ◽  
L. Klein ◽  
E. Wehrse ◽  
L. T. Rotkopf ◽  
C. Amato ◽  
...  
Keyword(s):  
Image Quality ◽  
Photon Counting ◽  
Dual Energy ◽  
Whole Body ◽  
Dual Energy Ct ◽  
Post Mortem ◽  
Tube Voltage ◽  
Spectral Separation ◽  
Dual Source ◽  
Noise Ratio

Abstract Objective To evaluate the dual-energy (DE) performance and spectral separation with respect to iodine imaging in a photon-counting CT (PCCT) and compare it to dual-source CT (DSCT) DE imaging. Methods A semi-anthropomorphic phantom extendable with fat rings equipped with iodine vials is measured in an experimental PCCT. The system comprises a PC detector with two energy bins (20 keV, T) and (T, eU) with threshold T and tube voltage U. Measurements using the PCCT are performed at all available tube voltages (80 to 140 kV) and threshold settings (50–90 keV). Further measurements are performed using a conventional energy-integrating DSCT. Spectral separation is quantified as the relative contrast media ratio R between the energy bins and low/high images. Image noise and dose-normalized contrast-to-noise ratio (CNRD) are evaluated in resulting iodine images. All results are validated in a post-mortem angiography study. Results R of the PC detector varies between 1.2 and 2.6 and increases with higher thresholds and higher tube voltage. Reference R of the EI DSCT is found as 2.20 on average overall phantoms. Maximum CNRD in iodine images is found for T = 60/65/70/70 keV for 80/100/120/140 kV. The highest CNRD of the PCCT is obtained using 140 kV and is decreasing with decreasing tube voltage. All results could be confirmed in the post-mortem angiography study. Conclusion Intrinsically acquired DE data are able to provide iodine images similar to conventional DSCT. However, PCCT thresholds should be chosen with respect to tube voltage to maximize image quality in retrospectively derived image sets. Key Points • Photon-counting CT allows for the computation of iodine images with similar quality compared to conventional dual-source dual-energy CT. • Thresholds should be chosen as a function of the tube voltage to maximize iodine contrast-to-noise ratio in derived image sets. • Image quality of retrospectively computed image sets can be maximized using optimized threshold settings.

P1-155: Post-Mortem Brain Tissue Characterisation of Inflammatory and Pathological Hallmarks of Alzheimer’s Disease During Disease Progression

2016 ◽  
Vol 12 ◽  
pp. P462-P462
Author(s):  
Martina M. Hughes ◽  
Beatriz G. Perez-Nievas ◽  
Claire Troakes ◽  
Michael Perkinton ◽  
Diane P. Hanger ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Disease Progression ◽  
Brain Tissue ◽  
Post Mortem ◽  
Tissue Characterisation ◽  
Post Mortem Brain

Comparison of Protein and Ribonucleic Acid Composition of Post Mortem Brain Tissue Between Controls and Cases of Alzheimer Type Dementia

1986 ◽  
pp. 451-455 ◽  
Author(s):  
J. C. Pascall ◽  
N. M. Borthwick ◽  
A. Curtis ◽  
V. Lyons ◽  
C. M. Yates
Keyword(s):  
Brain Tissue ◽  
Acid Composition ◽  
Ribonucleic Acid ◽  
Post Mortem ◽  
Alzheimer Type ◽  
Alzheimer Type Dementia ◽  
Post Mortem Brain

scholarly journals Natriuretic Peptides in Post-mortem Brain Tissue and Cerebrospinal Fluid of Non-demented Humans and Alzheimer’s Disease Patients

2018 ◽  
Vol 12 ◽  
Author(s):  
Simin Mahinrad ◽  
Marjolein Bulk ◽  
Isabelle van der Velpen ◽  
Ahmed Mahfouz ◽  
Willeke van Roon-Mom ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cerebrospinal Fluid ◽  
Brain Tissue ◽  
Natriuretic Peptides ◽  
Post Mortem ◽  
Post Mortem Brain

scholarly journals Emergence of distinct and heterogeneous strains of amyloid beta as Alzheimer′s disease progresses in Down syndrome

2021 ◽  
Author(s):  
Alison M Maxwell ◽  
Peng Yuan ◽  
Brianna M Rivera ◽  
Wilder Schaaf ◽  
Mihovil Mladinov ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Amyloid Beta ◽  
Fluorescent Probes ◽  
Clinical Symptoms ◽  
Critical Role ◽  
Phenotypic Heterogeneity ◽  
Post Mortem ◽  
Strain Profile ◽  
Post Mortem Brain ◽  
And Control

Amyloid beta (A&#946) is thought to play a critical role in the pathogenesis of Alzheimer&#8242s disease (AD). Prion-like Aβ polymorphs, or strains, can have varying pathogenicity and may underlie the phenotypic heterogeneity of the disease. In order to develop effective AD therapies, it is critical to identify the strains of A&#946 that might arise prior to the onset of clinical symptoms and understand how they may change with progressing disease. Down syndrome (DS), as the most common genetic cause of AD, presents promising opportunities to compare such features between early and advanced AD. In this work, we evaluate the neuropathology and A&#946 strain profile in the post-mortem brain tissues of 210 DS, AD, and control individuals. We assayed the levels of various A&#946 and tau species and used conformation-sensitive fluorescent probes to detect differences in A&#946 strains among individuals and populations. We found that these cohorts have some common but also some distinct strains from one another, with the most heterogeneous populations of A&#946 emerging in subjects with high levels of AD pathology. The emergence of distinct strains in DS at these later stages of disease suggests that the confluence of aging, pathology, and other DS-linked factors may favor conditions that generate strains that are unique from sAD.

scholarly journals LINE-1 and Alu methylation Signatures in Autism Spectrum Disorder and Their Function in The Regulation of Autism-Related Genes

2021 ◽  
Author(s):  
Thanit Saeliw ◽  
Tiravut Permpoon ◽  
Nutta Iadsee ◽  
Tewin Tencomnao ◽  
Tewarit Sarachana ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Dna Methylation ◽  
Autism Spectrum ◽  
Small Sample ◽  
Spectrum Disorder ◽  
Post Mortem ◽  
Global Methylation ◽  
Post Mortem Brain ◽  
Dna Methylation Profiling ◽  
Methylation Profiling

Abstract BackgroundLong interspersed nucleotide element-1 (LINE-1) and Alu elements are retrotransposons whose abilities cause abnormal gene expression and genomic instability. Several studies have focused on DNA methylation profiling of gene regions, but the locus-specific methylation of LINE-1 and Alu elements has not been identified in autism spectrum disorder (ASD).MethodsHere, DNA methylation age was predicted using Horvath’s method. We interrogated locus- and family-specific methylation profiles of LINE-1 and Alu elements (22,352 loci) in ASD blood using publicly-available Illumina Infinium 450K methylation datasets from heterogeneous ASD (n = 52), ASD with 16p11.2 del (n = 7), and ASD with Chromodomain Helicase DNA-binding 8 (CHD8) variants (n = 15). The differentially methylated positions of LINE-1 and Alu elements corresponding to genes were combined with transcriptome data from multiple ASD studies. ROC curve was conducted to examine the specificity of target loci.ResultsEpigenetic age acceleration was significantly decelerated in ASD children over the age of 11 years. DNA methylation profiling revealed LINE-1 and Alu methylation signatures in each ASD risk loci by which global methylation were notably hypomethylated exclusively in ASD with CHD8 variants. When LINE-1 and Alu elements were clustered into subfamilies, we found methylation changes in a family-specific manner in L1P, L1H, HAL, AluJ, and AluS families in the heterogeneous ASD and ASD with CHD8 variants. Our results showed that LINE-1 and Alu methylation within target genes is inversely related to the expression level in each ASD variant. Moreover, LINE-1 and Alu methylation signatures can be used to predict ASD individuals from non-ASD.LimitationsIntegration of methylome and transcriptome datasets was performed from different ASD cohorts. The small sample size of the validation cohort used post-mortem brain tissues and necessitates future validation in a larger cohort.ConclusionsThe DNA methylation signatures of the LINE-1 and Alu elements in ASD, as well as their functional impact on ASD-related genes, have been studied. These findings are considered for further research into DNA methylation profiles and the expression of the LINE-1 and Alu elements in post-mortem brain tissue, which has been linked to ASD pathogenesis.

RT-qPCR study on post-mortem brain samples from patients with major psychiatric disorders: Reference genes and specimen characteristics

2011 ◽  
Vol 45 (11) ◽  
pp. 1411-1418 ◽  
Author(s):  
Nerea Abasolo ◽  
Helena Torrell ◽  
Bàrbara Roig ◽  
Sílvia Moyano ◽  
Elisabet Vilella ◽  
...  
Keyword(s):  
Psychiatric Disorders ◽  
Reference Genes ◽  
Post Mortem ◽  
Post Mortem Brain

Post mortem brain alcohol levels

1983 ◽  
Vol 259 ◽  
pp. 353-355 ◽  
Author(s):  
Robert D. Budd
Keyword(s):  
Post Mortem ◽  
Post Mortem Brain

scholarly journals Magnetic resonance imaging and computed tomography of equine cheek teeth and adjacent structures: comparative study of image quality in horses in vivo, post-mortem and frozen-thawed

2019 ◽  
Vol 61 (1) ◽  
Author(s):  
Christin Röttiger ◽  
Maren Hellige ◽  
Bernhard Ohnesorge ◽  
Astrid Bienert-Zeit
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Post Mortem ◽  
Mr Images ◽  
Adjacent Structures ◽  
Group A ◽  
Group B ◽  
The Impact ◽  
Ct And Mri

Abstract Background The use of cadavers for radiology research methodologies involving subjective image quality evaluation of anatomical criteria is well-documented. The purpose of this method comparison study was to evaluate the image quality of dental and adjacent structures in computed tomography (CT) and high-field (3 T) magnetic resonance (MR) images in cadaveric heads, based on an objective four-point rating scale. Whilst CT is a well-established technique, MR imaging (MRI) is rarely used for equine dental diagnostics. The use of a grading system in this study allowed an objective assessment of CT and MRI advantages in portraying equine cheek teeth. As imaging is commonly performed with cadaveric or frozen and thawed heads for dental research investigations, the second objective was to quantify the impact of the specimens’ conditions (in vivo, post-mortem, frozen-thawed) on the image quality in CT and MRI. Results The CT and MR images of nine horses, focused on the maxillary premolar 08s and molar 09s, were acquired post-mortem (Group A). Three observers scored the dental and adjacent tissues. Results showed that MR sequences gave an excellent depiction of endo- and periodontal structures, whereas CT produced high-quality images of the hard tooth and bony tissues. Additional CT and MRI was performed in vivo (Group B) and frozen-thawed (Group C) in three of these nine horses to specify the condition of the best specimens for further research. Assessing the impact of the specimens’ conditions on image quality, specific soft tissues of the maxillary 08s and 09s including adjacent structures (pulps, mucosa of the maxillary sinuses, periodontal ligament, soft tissue inside the infraorbital canal) were graded in group B and C and analysed for significant differences within CT and MR modalities in comparison to group A. Results showed that MRI scores in vivo were superior to the post-mortem and frozen-thawed condition. Conclusions On comparing the imaging performance of CT and MRI, both techniques show a huge potential for application in equine dentistry. Further studies are needed to assess the clinical suitability of MRI. For further research investigations it must be considered, that the best MR image quality is provided in live horses.

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