Comparative analysis of in situ and ex situ postmortem brain MRI: Evaluating volumetry, DTI, and relaxometry.

PURPOSE: To compare postmortem in situ with ex situ MRI parameters, including volumetry, diffusion tensor imaging (DTI), and relaxometry for assessing methodology-induced alterations, which is a crucial prerequisite when performing MRI biomarker validation. METHODS: MRI whole-brain scans of five deceased patients with amyotrophic lateral sclerosis were performed at 3 T. In situ scans were conducted within 32 h after death (SD 18 h), and ex situ scans after brain extraction and 3 months of formalin fixation. The imaging protocol included MP2RAGE, DTI, and multi-contrast spin-echo and multi-echo gradient-echo sequences. Volumetry, fractional anisotropy, mean diffusivity, T1, T2, and T 2 * $$ {T}_2^{\ast } $$ have been assessed for specific brain regions. RESULTS: When comparing ex situ to in situ values, the following results were obtained. Deep gray matter as well as the thalamus and the hippocampus showed a reduced volume. Fractional anisotropy was reduced in the cortex and the whole brain. Mean diffusivity was decreased in white matter and deep gray matter. T1 and T2 were reduced in all investigated structures, whereas T 2 * $$ {T}_2^{\ast } $$ was increased in the cortex. CONCLUSION: The results of this study show that the volumes and MRI parameters of several brain regions are potentially affected by tissue extraction and subsequent formalin fixation, suggesting that methodological alterations are present in ex situ MRI. To avoid overlap of indistinguishable methodological and disease-related changes, we recommend performing in situ postmortem MRI as an additional intermediate step for in vivo MRI biomarker validation.

The Lateral Corticospinal Tract Sign: An MRI Marker for Amyotrophic Lateral Sclerosis.

Background Radially sampled averaged magnetization inversion-recovery acquisition (rAMIRA) imaging shows hyperintensity in the lateral corticospinal tract (CST) in patients with motor neuron diseases. Purpose To systematically determine the accuracy of the lateral corticospinal tract sign for detecting patients with amyotrophic lateral sclerosis (ALS) at rAMIRA MRI. Materials and Methods This study included prospectively acquired data from participants in ALS and other motor neuron disease imaging studies at the University Hospital Basel, Switzerland. All participants underwent 3-T axial two-dimensional rAMIRA imaging at four cervical intervertebral disk levels. The lateral CST sign was defined as spinal cord white matter hyperintensity dorsolateral to the anterior horns, with higher signal intensity than in the dorsal columns on axial rAMIRA images. Marker accuracy was assessed in a study data set and in an independent validation data set. Postmortem rAMIRA imaging and histopathologic analysis were performed in one participant who died during the study. Results Participants with ALS (study data set: 38 participants [mean age, 61 years; IQR, 15 years], 22 male participants; validation data set: 10 participants [mean age, 61 years; IQR, 21 years], seven male participants), post-polio syndrome (study data set: 25 participants [mean age, 68 years; IQR, 8 years], 12 male participants), spinal muscular atrophy (study data set: 10 participants [mean age, 43 years; IQR, 14 years], eight male participants; validation data set: five participants [mean age, 38 years; IQR, 19 years], two male participants), and healthy control participants (study data set: 60 participants [mean age, 57 years; IQR, 20 years], 36 male participants; validation data set: 10 participants [mean age, 44 years; IQR, 17 years], seven male participants) were included. The sensitivity and specificity of rAMIRA for ALS were 60% (23 of 38) and 97% (91 of 94) in the study data set and 100% (10 of 10) and 93% (14 of 15) in the validation data set, respectively. Histopathologic analysis showed distinct loss of myelinated axons in the localization of the hyperintensities observed at rAMIRA imaging performed in situ and after organ extraction. Conclusion The recently defined marker at rAMIRA MRI may be a promising tool for assessing upper motor neuron degeneration in the lateral CST in patients with ALS. Clinical trials registration no. NCT03561623, NCT05764434, NCT06137612 © RSNA, 2024 Supplemental material is available for this article.

When alienated from society, conspiracy theory belief gives meaning to life.

Background: Conspiracy theory belief - explaining the ultimate causes of social and political events with claims of secret conspiracies - is assumed to arise from a desire to make sense of uncertainty, especially in times of crisis. However, there is no compelling evidence that conspiracy theory belief actually fulfils this function, particularly in terms of evaluating one's life as meaningful. We posit that the adoption of conspiracy theory belief can be explained as a fluid compensation when a more proximal source of meaning, a sense of belonging to society, is threatened. Thus, a positive association between conspiracy theory belief and meaningfulness should emerge when people feel alienated from society. We therefore tested the hypotheses that alienation from society correlates negatively with meaningfulness (H1), and that it moderates the relationship between conspiracy theory belief and meaningfulness (H2). Method: Conspiracy theory belief related to the COVID-19 pandemic, meaningfulness (Meaning and Purpose Scales, MAPS), and perceived alienation from society were assessed in a representative sample of N = 974 German residents. Results: As expected, alienation from society was inversely related to meaningfulness and moderated the relationship between conspiracy theory belief and meaningfulness. According to the interaction, a positive association between belief in conspiracy theory and meaningfulness emerged when individuals experienced themselves as alienated from society. Conclusion: The results suggest that conspiracy theory belief might alleviate a lack of meaningfulness caused by experienced alienation from society. Individuals who felt discriminated against, treated unequally, or having their rights restricted were more likely to hold conspiracy theory belief, which was associated with a greater sense of meaning in their lives.

Longitudinal visibility of MRI findings in living victims of strangulation.

Initial experiences with magnetic resonance imaging (MRI) of living strangulation victims demonstrated additional findings of internal injuries compared to the standard clinical forensic examination. However, existing studies on the use of MRI for this purpose mostly focused on the first 48 h after the incident. The aims of this study were (a) to evaluate the longitudinal visibility of MRI findings after violence against the neck by performing two MRI examinations within 12 days and a minimum of four days between both MRI scans and (b) to assess which MRI sequences were most helpful for the detection of injuries. Twenty strangulation victims participated in this study and underwent one (n = 8) or two (n = 12) MRI scans. The first MRI examination was conducted during the first five days, the second five to 12 days after the incident. Two blinded radiologists assessed the MRI data and looked for lesions in the structures of the neck. In total, 140 findings were reported in the 32 MRI examinations. Most of the findings were detected in the thyroid and the muscles of the neck. T2-weighted SPACE with fat suppression, T1-weighted TSE and T1-weighted MPRAGE were rated as the most helpful MRI sequences. Subjects who showed findings in the initial scan also demonstrated comparable results in the second scan, which was performed on average 8.4 days after the incident. Our results show that even up to 12 days after the incident, the criminal proceeding of strangulation cases may greatly profit from the information provided by an MRI examination of the neck in addition to the standard clinical forensic examination.

Automated detection of fatal cerebral haemorrhage in postmortem CT data.

During the last years, the detection of different causes of death based on postmortem imaging findings became more and more relevant. Especially postmortem computed tomography (PMCT) as a non-invasive, relatively cheap, and fast technique is progressively used as an important imaging tool for supporting autopsies. Additionally, previous works showed that deep learning applications yielded robust results for in vivo medical imaging interpretation. In this work, we propose a pipeline to identify fatal cerebral haemorrhage on three-dimensional PMCT data. We retrospectively selected 81 PMCT cases from the database of our institute, whereby 36 cases suffered from a fatal cerebral haemorrhage as confirmed by autopsy. The remaining 45 cases were considered as neurologically healthy. Based on these datasets, six machine learning classifiers (k-nearest neighbour, Gaussian naive Bayes, logistic regression, decision tree, linear discriminant analysis, and support vector machine) were executed and two deep learning models, namely a convolutional neural network (CNN) and a densely connected convolutional network (DenseNet), were trained. For all algorithms, 80% of the data was randomly selected for training and 20% for validation purposes and a five-fold cross-validation was executed. The best-performing classification algorithm for fatal cerebral haemorrhage was the artificial neural network CNN, which resulted in an accuracy of 0.94 for all folds. In the future, artificial neural network algorithms may be applied by forensic pathologists as a helpful computer-assisted diagnostics tool supporting PMCT-based evaluation of cause of death.

Optimizing the Gut Microbiota for Individualized Performance Development in Elite Athletes.

The human gut microbiota can be compared to a fingerprint due to its uniqueness, hosting trillions of living organisms. Taking a sport-centric perspective, the gut microbiota might represent a physiological system that relates to health aspects as well as individualized performance in athletes. The athletes' physiology has adapted to their exceptional lifestyle over the years, including the diversity and taxonomy of the microbiota. The gut microbiota is influenced by several physiological parameters and requires a highly individual and complex approach to unravel the linkage between performance and the microbial community. This approach has been taken in this review, highlighting the functions that the microbial community performs in sports, naming gut-centered targets, and aiming for both a healthy and sustainable athlete and performance development. With this article, we try to consider whether initiating a microbiota analysis is practicable and could add value in elite sport, and what possibilities it holds when influenced through a variety of interventions. The aim is to support enabling a well-rounded and sustainable athlete and establish a new methodology in elite sport.

Temperature correction of post mortem quantitative magnetic resonance imaging using real-time forehead temperature acquisitions.

Performing magnetic resonance imaging (MRI) of deceased is challenging due to altered body temperatures compared to in vivo temperatures and, hence, requires a temperature correction. This study investigates the possibility to correct brain MRI parameters real-time and non invasively based on the forehead temperature. 17 post mortem cases were included and their forehead temperatures were measured continuously during the in situ brain MRI protocol consisting of a diffusion tensor imaging, multi-contrast spin echo, multi-echo gradient echo and inversion recovery spin echo sequence. Linear models were fitted to the quantitative MRI parameters in a forensically interesting temperature range for white matter, cerebral cortex and deep gray matter, separately, and the influence of the forehead temperature on the MRI parameters was determined. A statistically significant temperature sensitivity was found for T2 and mean diffusivity in white matter, for T1 in cerebral cortex, as well as for T1 and mean diffusivity in deep gray matter. Linear models were computed to temperature correct these MRI parameters in in situ post mortem scans to allow their comparison regardless of temperature. The here presented real-time and non invasive temperature correction method for the brain presents a crucial precondition for quantitative in situ post mortem MRI.

Investigation of post mortem brain, rectal and forehead temperature relations.

It is well known that magnetic resonance (MR) imaging is temperature sensitive, which is highly relevant for post mortem examinations. Therefore, the determination of the exact temperature of the investigated body site, e.g. the brain, is crucial. However, direct temperature measurements are invasive and inconvenient. Thus, in view of post mortem MR imaging of the brain, this study aims at investigating the relation between the brain and the forehead temperature for modelling the brain temperature based on the non-invasive forehead temperature. In addition, the brain temperature will be compared to the rectal temperature. Brain temperature profiles measured in the longitudinal fissure between the brain hemispheres, as well as rectal and forehead temperature profiles of 16 deceased were acquired continuously. Linear mixed, linear, quadratic and cubic models were fitted to the relation between the longitudinal fissure and the forehead and between the longitudinal fissure and the rectal temperature, respectively. Highest adjusted R2 values were found between the longitudinal fissure and the forehead temperature, as well as between the longitudinal fissure and the rectal temperature using a linear mixed model including the sex, environmental temperature and humidity as fixed effects. The results indicate that the forehead, as well as the rectal temperature, can be used to model the brain temperature measured in the longitudinal fissure. Comparable fit results were observed for the longitudinal fissure-forehead temperature relation and for the longitudinal fissure-rectal temperature relation. Combined with the fact that the forehead temperature overcomes the problem of measurement invasiveness, the results suggest using the forehead temperature for modelling the brain temperature in the longitudinal fissure.

Fully automated radiologic identification focusing on the sternal bone.

A crucial task in forensic investigations is the identification of unknown deceased. In general, secure identification methods rely on a comparison of ante mortem (AM) with post mortem (PM) data. However, available morphologic approaches are often dependent on the expertise and experience of the examiner, and often lack standardisation and statistical evidence. The objective of this study was therefore to overcome the current challenges via developing a fully automated radiologic identification (autoRADid) method based on the sternal bone. An anonymised AM data set consisting of 91 chest computed tomography (CT) scans, as well as an anonymised PM data set of 42 chest CT scans were included in this work. Out of the 91 available AM CT data sets, 42 AM scans corresponded to the 42 PM CT scans. For the fully automated identification analysis, a custom-made python pipeline was developed, which automatically registers AM data to the PM data in question using a two-step registration method. To evaluate the registration procedure and subsequent identification success, the image similarity measures Jaccard Coefficient, Dice Coefficient, and Mutual Information were computed. The highest value for each metric was retrieved in order to analyse the correspondence between AM and PM data. For all three similarity measures, 38 out of the 42 cases were matched correctly. This corresponds to an accuracy of 91.2%. The four unsuccessful cases incorporated surgical interventions taking place between the AM and the PM CT acquisition or poor CT scan quality preventing robust registration results. To conclude, the presented autoRADid method seems to be a promising fully automated tool for a reliable and facile identification of unknown deceased. A final pipeline combining all three similarity measures is open source and publicly available for efficient future identifications of unknown deceased.

Technical note: Quantitative optimization of the FLAIR sequence in post mortem magnetic resonance imaging.

The fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) sequence aims at suppressing the signal of the cerebrospinal fluid (CSF) by acquiring images at the time point at which the longitudinal magnetization and therefore the signal of CSF is zero. This time point is also called the null point inversion time (TInull). However, the FLAIR sequence is impaired by the temperature dependency of TInull in post mortem MRI due to the lower body temperature of the deceased subject. Therefore, the temperature correction of TInull is crucial for correctly suppressing the CSF signal in post mortem FLAIR imaging. Thus, the goal of this study was to determine the temperature effect on post mortem TInull for achieving a robust suppression of the CSF signal in in situ post mortem MRI using the FLAIR sequence. For this purpose, nine deceased subjects underwent an in situ MRI brain examination on a 3 T MRI scanner. TInull of CSF was determined quantitatively based on different FLAIR acquisitions using varying inversion times. The brain and rectal temperatures were determined prior to the MRI scan. A significant positive linear relation was found between TInull of CSF and the brain temperature, as well as between TInull of CSF and the rectal temperature. The found linear relations between TInull and both brain and rectal temperatures allow correcting TInull for varying temperatures of the deceased. This in turn enables an optimal suppression of the CSF signal in future post mortem FLAIR MRI acquisitions.

Post mortem evaluation of brain edema using quantitative MRI.

The post mortem assessment of brain edema is routinely performed during autopsy by forensic pathologists who evaluate the macroscopically visible signs. In this study, the suitability of magnetic resonance imaging (MRI) for a differentiation between edematous and nonedematous brains was examined as an objective, noninvasive and quantitative rating method. In this study, 22 deceased underwent post mortem in situ MRI prior to regular autopsy. Acquired MRI sequences allowed the computation of the quantitative MRI parameters T1, T2, T2*, fractional anisotropy (FA) and mean diffusivity for the cortex, white matter and deep gray matter separately. Beside the autopsy results, which represent the gold standard for rating brain edema, also the normalized cerebral weight (NCW) was determined by dividing the brain weight by the intracranial volume as developed by Bauer et al. [10]. For further examination of the relation of MRI parameters with the NCW, linear regression models were calculated. The results revealed highly significant correlations of the MRI parameters T2 and FA with the NCW in the cortex. These combinations additionally showed the best fitting results of the linear regression models. In conclusion, quantitative MRI is suitable for differentiating edematous from nonedematous brains by calculating T2 and FA in the cortex. A post mortem in situ MRI scan of the brain can, besides delivering morphological information, add relevant and objective information on the edema status of the brain prior to autopsy or when no autopsy is ordered.

Determination of time of death by blinded post-mortem interrogation of cardiac implantable electrical devices.

Postmortal interrogation of cardiac implantable electrical devices (CIED) may contribute to the determination of time of death in forensic medicine. Recent studies aimed to improve estimation of time of death by combining findings from autopsy, CIED interrogation and patients´ medical history. CIED from deceased undergoing forensic autopsy were included, if time of death remained unclear after forensic assessment. CIED explanted from deceased with known time of death were analysed as a control cohort. CIED were sent to our device interrogation lab and underwent analysis blinded for autopsy findings, medical history and police reports. The accuracy of time of death determination and the accuracy of time of death in the control cohort served as primary outcome. A total of 87 CIED were analysed. The determination of time of death was possible in 54 CIED (62%, CI 52-72%). The accuracy of the estimated time of death was 92.3% in the control cohort. Certain CIED type and manufacturers were associated with more successful determination. Blinded postmortal analysis enables a valid determination of the time of death in the majority of CIED. Analysis of explanted CIED in a cardiological core lab is feasible and should be implemented in forensic medicine.

Post mortem brain temperature and its influence on quantitative MRI of the brain.

OBJECTIVE: MRI temperature sensitivity presents a major issue in in situ post mortem MRI (PMMRI), as the tissue temperatures differ from living persons due to passive cooling of the deceased. This study aims at computing brain temperature effects on the MRI parameters to correct for temperature in PMMRI, laying the foundation for future projects on post mortem validation of in vivo MRI techniques. MATERIALS AND METHODS: Brain MRI parameters were assessed in vivo and in situ post mortem using a 3 T MRI scanner. Post mortem brain temperature was measured in situ transethmoidally. The temperature effect was computed by fitting a linear model to the MRI parameters and the corresponding brain temperature. RESULTS: Linear positive temperature correlations were observed for T1, T2* and mean diffusivity in all tissue types. A significant negative correlation was observed for T2 in white matter. Fractional anisotropy revealed significant correlations in all gray matter regions except for the thalamus. DISCUSSION: The linear models will allow to correct for temperature in post mortem MRI. Comparing in vivo to post mortem conditions, the mean diffusivity, in contrast to T1 and T2, revealed additional effects besides temperature, such as cessation of perfusion and active diffusion.

Sensitivity of fiber orientation dependent R2∗ to temperature and post mortem interval.

PURPOSE: R2∗ imaging of brain white matter is well known for being sensitive to the orientation of nerve fibers with respect to the B0 field of the MRI scanner. The goal of this study was to evaluate whether and to which extent fiber orientation dependent R2∗ differs between in vivo and post mortem in situ examinations, and to investigate the influence of varying temperatures and post mortem intervals (PMI). METHODS: Post mortem in situ and in vivo MRI scans were conducted at 3T. R2∗ was acquired with a multi-echo gradient-echo sequence, and the orientation of white matter fibers was computed using diffusion tensor imaging (DTI). Fitting of the measured fiber orientation dependent R2∗ was performed using three different formulations of a previously proposed model. RESULTS: R2∗ increased with increasing fiber angle for in vivo and post mortem in situ examinations, whereby the orientation dependency was lower post mortem. The different formulations of the fiber orientation model resulted in an identical fit, but showed large variations of the estimated parameters. The higher order orientation dependent R2∗ components significantly decreased with decreasing temperature, while the orientation independent R2∗ components showed no significant correlation with either temperature or PMI. CONCLUSION: Although the mean diffusivity is strongly reduced post mortem, we could successfully estimate the fiber angle using DTI. Due to the strong correlation of the higher order orientation dependent R2∗ components with temperature, the decreased R2∗ fiber orientation dependency post mortem in situ might primarily be attributed to the lower brain temperature.

Tissue sample analysis for post mortem determination of brain edema.

The post mortem evaluation of a brain edema is routinely performed by pathologists based on the macroscopic signs during autopsy. This method represents the current gold standard, but is subjective and observer dependent. Therefore, three post mortem evaluation methods of brain samples were analyzed in this work: histology, wet-dry weight and normalized cerebral weight, which was described in 2020 by Bauer et al. Tissue samples from six different regions of 34 brains were collected and examined both by rating of histological slides and by measuring the water content by using a drying oven. The rating of the histological slides, stained with hematoxylin and eosin, was performed by two pathologists independently. For the water content, the wet weight and the dry weight of each sample were set in relation. The normalized cerebral weight was calculated by dividing the brain weight by the brain volume, which were both determined during autopsy and in computed tomography images, respectively. A fair to moderate interrater agreement was obtained for the histologic evaluation and a significant correlation was present between one rater and the wet-dry weight and the normalized cerebral weight method. When classifying according to the gold standard, a significant difference was detected between the edematous and nonedematous cases by using the wet-dry weight method in the cerebral cortex and by using the normalized cerebral weight method. However, the significant correlations and group differences were limited to the aforementioned results. In conclusion, both the histological and the wet-dry weight method show limited benefits for the classification of brain edema and the histology analysis is highly observer dependent. The normalized cerebral weight method, however, reveals a significant effect between the edematous and nonedematous cases when classifying according to the gold standard. Therefore, we suggest to apply this method for the assessment of brain edema since it is objective and rater independent. Nevertheless, the exact evaluation of brain edema remains a challenging task, especially due to the continuous transition between no edema and edema.

Analysis of different post mortem assessment methods for cerebral edema.

While cerebral edema is a live-threatening condition in living persons, also an edema-like fluid redistribution can occur post mortem. In deceased, usually macroscopic signs are evaluated during autopsy in order to determine the presence or absence of cerebral edema. As a quantitative and objective classification is beneficial, an already existing method (Radojevic et al., 2017), which is based on a mathematical formula using the intracranial dimensions and the cerebral weight, was compared to the evaluation of macroscopic signs in 31 cases. The results showed an excellent agreement for the comparison between the raters as well as the measurement methods (at opened skull or in CT images). However, both measurement methods only poorly agree with the macroscopic edema evaluation. In order to find a more concordant method, the normalized cerebral weight, which puts the cerebral weight in relation to the intracranial volume, was calculated for 115 cases. This method resulted in an excellent agreement with the macroscopic rating and showed a clear numerical difference between the edematous and nonedematous group. While the influence of the post mortem time and the cooling time was found to be negligible, the age at death might confound the edema classification due to pre-existing cerebral atrophy leading to lower cerebral weights. In summary, the present study compared different assessment methods to classify cerebral edema and developed a rater independent, objective and quantitative classification method, which was as reliable as the rating of the forensic pathologists.

No associations between medial temporal lobe volumes and verbal learning/memory in emerging psychosis.

Grey matter (GM) volume alterations have been repeatedly demonstrated in patients with first episode psychosis (FEP). Some of these neuroanatomical abnormalities are already evident in the at-risk mental state (ARMS) for psychosis. Not only GM alterations but also neurocognitive impairments predate the onset of frank psychosis with verbal learning and memory (VLM) being among the most impaired domains. Yet, their interconnection with alterations in GM volumes remains ambiguous. Thus, we evaluated associations of different subcortical GM volumes in the medial temporal lobe with VLM performance in antipsychotic-naïve ARMS and FEP patients. Data from 59 ARMS and 31 FEP patients, collected within the prospective Früherkennung von Psychosen study, were analysed. Structural T1-weighted images were acquired using a 3 Tesla magnetic resonance imaging scanner. VLM was assessed using the California Verbal Learning Test and its factors Attention Span, Learning Efficiency, Delayed Memory and Inaccurate Memory. FEP patients showed significantly enlarged volumes of hippocampus, pallidum, putamen and thalamus compared to ARMS patients. A significant negative association between amygdala and pallidum volume and Attention Span was found in ARMS and FEP patients combined, which however did not withstand correction for multiple testing. Although we found significant between-group differences in subcortical volumes and VLM is among the most impaired cognitive domains in emerging psychosis, we could not demonstrate an association between low performance and subcortical GM volumes alterations in antipsychotic-naïve patients. Hence, deficits in this domain do not appear to stem from alterations in subcortical structures.

Systematic review on the characterization of chronic traumatic encephalopathy by MRI and MRS.

BACKGROUND: Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease that is found in people who have suffered from chronic traumatic brain injury (TBI). Up to now, diagnosis of CTE could only be made based on postmortem histopathological examinations. The application of MR techniques might offer a promising possibility for in vivo diagnoses. PURPOSE/HYPOTHESIS: To provide a critical systematic review of the characterization of chronic TBI and CTE by considering the range of MR techniques. STUDY TYPE: This was a systematic review for which the electronic databases PubMed and Embase were searched using the terms ("chronic traumatic encephalopathy" OR "punch drunk syndrome" OR "chronic traumatic brain injury" OR "dementia pugilistica" OR "chronic head trauma") AND ("magnetic resonance imaging" OR mri OR imaging OR mrs OR "magnetic resonance spectroscopy" OR spectroscopy). POPULATION/SUBJECTS/PHANTOM/SPECIMEN/ANIMAL MODEL: Of the 432 studies identified by the database search, 25 were included in this review. FIELD STRENGTH/SEQUENCE: Diffusion, structural, and functional MRI sequences and MR spectroscopy were evaluated at 1.5T or 3T and at 11.74T for the ex vivo studies. ASSESSMENT: Data were extracted by two reviewers independently. Specific inclusion and exclusion criteria like the study design, publication type, and applied MR techniques were used to select studies for review. STATISTICAL TESTS: Results of the original research articles were stated in this review as significant if P ≤ 0.05. RESULTS: Of the included articles, two were ex vivo studies focusing on the coregistration of histology and MRI. All other studies were based on in vivo data. DATA CONCLUSION: The included studies varied considerably regarding study setup, MR techniques, and results. Nevertheless, this work aims to establish links between the studies and discusses the results and limitations associated with the characterization of chronic TBI and CTE based on MR. LEVEL OF EVIDENCE: 3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:212-228.

Sexually dimorphic subcortical brain volumes in emerging psychosis.

BACKGROUND: In schizophrenic psychoses, the normal sexual dimorphism of the brain has been shown to be disrupted or even reversed. Little is known, however, at what time point in emerging psychosis this occurs. We have therefore examined, if these alterations are already present in the at-risk mental state (ARMS) for psychosis and in first episode psychosis (FEP) patients. METHODS: Data from 65 ARMS (48 (73.8%) male; age=25.1±6.32) and 50 FEP (37 (74%) male; age=27±6.56) patients were compared to those of 70 healthy controls (HC; 27 (38.6%) male; age=26±4.97). Structural T1-weighted images were acquired using a 3 Tesla magnetic resonance imaging (MRI) scanner. Linear mixed effects models were used to investigate whether subcortical brain volumes are dependent on sex. RESULTS: We found men to have larger total brain volumes (p<0.001), and smaller bilateral caudate (p=0.008) and hippocampus volume (p<0.001) than women across all three groups. Older subjects had more GM and WM volume than younger subjects. No significant sex×group interaction was found. CONCLUSIONS: In emerging psychosis there still seem to exist patterns of normal sexual dimorphism in total brain and caudate volume. The only structure affected by reversed sexual dimorphism was the hippocampus, with women showing larger volumes than men even in HC. Thus, we conclude that subcortical volumes may not be primarily affected by disrupted sexual dimorphism in emerging psychosis.

Identification of deceased based on sternal bone computed tomography features.

Identification of deceased with unclear identity is a common problem in forensic science, whereby radiologic comparison can be applied as method for identification. As this comparison is mostly made on a visual basis, it is highly dependent on the examiner and often lacks standardized procedures and statistical support. The aim of this study therefore was to develop a reproducible and examiner independent method for radiologic identification (RADid) based on morphometric and morphological features of sternal bone computed tomography (CT). Furthermore, the feasibility of an automated comparison of a post-mortem (PM) case against a database of ante-mortem (AM) cases was evaluated. 44 in situ PM CT scans of sternal bone and their corresponding AM CT scans were analysed and reproducible features were selected based on intra- and interrater reliability assessments. The selected features were further tested by contrasting AM and PM data. Moreover, an automated identity evaluation was developed by calculating the number of matching features between each PM case and an AM database consisting of 94 cases including the 44 with corresponding PM scans. Several features showed to be reliable according to their resulting correlation coefficient values (greater or equal to 0.60). The suitability and stability of these features was confirmed by contrasting AM and PM CT scans. Finally, the automated comparison was successful in 76.7% of the cases, whereby an unambiguous identification was possible in 65.1%. The present study reflects the benefits of a standardized and statistically established identification method and demonstrates the high potential of the sternal bone as a suitable structure for RADid.