Big Field of View MRI T1w and FLAIR Template - NMRI225.

Image templates are a common tool for neuroscience research. Often, they are used for spatial normalization of magnetic resonance imaging (MRI) data, which is a necessary procedure for analyzing brain morphology and function via voxel-based analysis. This allows the researcher to reduce individual shape differences across images and make inferences across multiple subjects. Many templates have a small field-of-view typically focussed on the brain, limiting the use for applications requiring detailed information about other extra-cranial structures in the head and neck area. However, there are several applications where such information is important, for example source reconstruction of electroencephalography (EEG) and/or magnetoencephalography (MEG). We have constructed a new template based on 225 T1w and FLAIR images with a big field-of-view that can serve both as target for across subject spatial normalization as well as a basis to build high-resolution head models. This template is based on and iteratively re-registered to the MNI152 space to provide maximal compatibility with the most commonly used brain MRI template.

Combined electrophysiological and morphological phenotypes in patients with genetic generalized epilepsy and their healthy siblings.

OBJECTIVE: Genetic generalized epilepsy (GGE) is characterized by aberrant neuronal dynamics and subtle structural alterations. We evaluated whether a combination of magnetic and electrical neuronal signals and cortical thickness would provide complementary information about network pathology in GGE. We also investigated whether these imaging phenotypes were present in healthy siblings of the patients to test for genetic influence. METHODS: In this cross-sectional study, we analyzed 5 min of resting state data acquired using electroencephalography (EEG) and magnetoencephalography (MEG) in patients, their siblings, and controls, matched for age and sex. We computed source-reconstructed power and connectivity in six frequency bands (1-40 Hz) and cortical thickness (derived from magnetic resonance imaging). Group differences were assessed using permutation analysis of linear models for each modality separately and jointly for all modalities using a nonparametric combination. RESULTS: Patients with GGE (n = 23) had higher power than controls (n = 35) in all frequencies, with a more posterior focus in MEG than EEG. Connectivity was also increased, particularly in frontotemporal and central regions in theta (strongest in EEG) and low beta frequencies (strongest in MEG), which was eminent in the joint EEG/MEG analysis. EEG showed weaker connectivity differences in higher frequencies, possibly related to drug effects. The inclusion of cortical thickness reinforced group differences in connectivity and power. Siblings (n = 18) had functional and structural patterns intermediate between those of patients and controls. SIGNIFICANCE: EEG detected increased connectivity and power in GGE similar to MEG, but with different spectral sensitivity, highlighting the importance of theta and beta oscillations. Cortical thickness reductions in GGE corresponded to functional imaging patterns. Our multimodal approach extends the understanding of the resting state in GGE and points to genetic underpinnings of the imaging markers studied, providing new insights into the causes and consequences of epilepsy.

Strained-layer-superlattice-based compact thermal imager for the International Space Station.

The compact thermal imager (CTI) is a dual-band, strained-layer-superlattice (SLS) detector-based instrument that was installed on the exterior of the International Space Station (ISS) in conjunction with the third Robotic Refueling Mission 3 (RRM3) in 2018. The CTI serves as a pathfinder for future thermal infrared capability on Landsat. The CTI incorporates an SLS hybrid, a dual-band 3-5 and 8-10 µm, electrically switchable, 320×256 array with 30 µm2 pixels, bonded to an Indigo ISC0903 Readout Integrated Circuit (ROIC). The telescope was built around an integrated detector cryocooler assembly developed under a NASA Small Business Innovative Research award with QmagiQ, LLC. The cooler is a Ricor K508 and the front-end optics is a custom-designed, doublet lens telescope with a 150 mm focal length. The ground resolution is 80 meters/pixel from the ISS altitude of 400 km. A filter creates two spectral channels from the dual bands, 3.3-5.4 and 7.8-10.2 µm. The detector hybrid control electronics is a custom-developed system based on the Teledyne Imaging Systems SIDECAR Application-Specific Integrated Circuit. This module provides the electronic interface from the RRM3 SpaceCube on-board processor to the detector/ROIC assembly. The primary goal of this mission was to perform a technology demonstration of the SLS technology and the commercial cooler technology elevating the Technology Readiness Level (TRL) to TRL 9 on a bare-bones budget and relatively fast development cycle. Some science objectives include locating fires, approximating land surface temperatures, and monitoring evapotranspiration, sea ice, and glacier dynamics. In this paper, we will present the design of the focal plane, optics, electronics, and mechanical structure of the CTI. We will also describe the operation and qualification tests that were performed to bring the CTI to the NASA TRL 6 in preparation for the launch on a SpaceX Dragon from the Kennedy Space Center.

An observational study on quality of life and preferences to sustain life in locked-in state.

OBJECTIVE: This is an observational study on well-being and end-of-life preferences in patients with amyotrophic lateral sclerosis (ALS) in the locked-in state (LIS) in a Polish sample within the EU Joint Programme-Neurodegenerative Disease Research study NEEDSinALS (NEEDSinALS.com). METHODS: In this cross-sectional study, patients with ALS in LIS (n = 19) were interviewed on well-being (quality of life, depression) as a measure of psychosocial adaptation, coping mechanisms, and preferences towards life-sustaining treatments (ventilation, percutaneous endoscopic gastroscopy) and hastened death. Also, clinical data were recorded (ALS Functional Rating Scale-revised version). Standardized questionnaires (Anamnestic Comparative Self-Assessment [ACSA], Schedule for the Evaluation of Individual Quality of Life-Direct Weighting (SEIQoL-DW), ALS Depression Inventory-12 items [ADI-12], schedule of attitudes toward hastened death [SAHD], Motor Neuron Disease Coping Scale) were used, which were digitally transcribed; answers were provided via eye-tracking control. In addition, caregivers were asked to judge patients' well-being. RESULTS: The majority of patients had an ACSA score >0 and a SEIQoL score >50% (indicating positive quality of life) and ADI-12 <29 (indicating no clinically relevant depression). Physical function did not reflect subjective well-being; even more, those with no residual physical function had a positive well-being. All patients would again choose the life-sustaining techniques they currently used and their wish for hastened death was low (SAHD <10). Caregivers significantly underestimated patient's well-being. INTERPRETATION: Some patients with ALS in LIS maintain a high sense of well-being despite severe physical restrictions. They are content with their life-sustaining treatments and have a strong will to live, which both may be underestimated by their families and public opinion.

Cognitive phenotypes of sequential staging in amyotrophic lateral sclerosis.

Sequential spread of TDP-43 load in the brain may be a pathological characteristic of amyotrophic lateral sclerosis (ALS). Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) based marker of this pathological feature. Cognitive deficits known to be present in a subset of ALS patients might act as an additional in vivo clinical marker of disease spread. N = 139 patients with ALS were tested with the Edinburgh Cognitive and Behavioural ALS screen (ECAS) in addition to DTI brain measures of pathological spread. Executive function, memory and disinhibited behaviour were selected for Cognitive-Staging criteria, as these cognitive functions are attributed to cerebral areas analogous to the pattern of MRI markers of TDP-43 pathology. ROC curve analyses were performed to define cut-off scores for cognitive stages 2 (executive function), stage 3 (disinhibited behaviour) and stage 4 (memory), and staging was performed according to the cognitive profile subsequently. Associations of Cognitive-Staging (stage 2-4) and MRI-Staging measures were determined. In total, 77 patients (55%) performed below ROC cut-off scores in either executive function or memory or both and/or were reported to have disinhibited behaviour which permitted Cognitive-Staging. The cognitive profile of patients with discrete MRI stages 2-4 correlated significantly with DTI parameters. For those patients with cognitive impairment, there was a high congruency between MRI and Cognitive-Staging with high specificity and sensitivity of executive functions for MRI stage 2, disinhibited behaviour for MRI stage 3 and moderate of memory for MRI stage 4. Cognitive impairment follows specific patterns in ALS and these patterns can be used for Cognitive-Staging with a high specificity compared to MRI-Staging. For the individual, cognitive screening is a fast and easy to apply measurement of cerebral function giving valuable information in a clinical context.

Functional reorganization during cognitive function tasks in patients with amyotrophic lateral sclerosis.

Cognitive deficits, especially in the domains of social cognition and executive function including verbal fluency, are common in amyotrophic lateral sclerosis (ALS) patients. There is yet sparse understanding of pathogenesis of the underlying, possibly adaptive, cortical patterns. To address this issue, 65 patients with ALS and 33 age-, gender- and education-matched healthy controls were tested on cognitive and behavioral deficits with the Edinburgh Cognitive and Behavioural ALS Screen (ECAS). Using functional magnetic resonance imaging (fMRI), cortical activity during social cognition and executive function tasks (theory of mind, verbal fluency, alternation) adapted from the ECAS was determined in a 3 Tesla scanner. Compared to healthy controls, ALS patients performed worse in the ECAS overall (p < 0.001) and in all of its subdomains (p < 0.02), except memory. Imaging revealed altered cortical activation during all tasks, with patients consistently showing a hyperactivation in relevant brain areas compared to healthy controls. Additionally, cognitively high performing ALS patients consistently exhibited more activation in frontal brain areas than low performing patients and behaviorally unimpaired patients presented with more neuronal activity in orbitofrontal areas than behaviorally impaired patients. In conclusion, hyperactivation in fMRI cognitive tasks seems to represent an early adaptive process to overcome neuronal cell loss in relevant brain areas. The hereby presented cortical pattern change might suggest that, once this loss passes a critical threshold and no cortical buffering is possible, clinical representation of cognitive and behavioral impairment evolves. Future studies might shed light on the pattern of cortical pattern change in the course of ALS.

Age and education-matched cut-off scores for the revised German/Swiss-German version of ECAS.

The Edinburgh Cognitive and Behavioural ALS Screen (ECAS) has been developed to assess cognition and behaviour in patients with amyotrophic lateral sclerosis (ALS). Cognitive impairments of ALS-specific and ALS-non-specific functions can be determined using cut-off scores based on performance of healthy subjects. However, detailed analyses show that older healthy subjects perform worse than younger ones, whereas highly-educated individuals perform better than those with lower education levels. As a consequence, this study presents new age and education matched cut-off scores for the revised German/Swiss-German version of the ECAS based on the performance of 86 healthy subjects.

Interpixel crosstalk in Teledyne Imaging Sensors H4RG-10 detectors.

Complementary metal-oxide semiconductor (CMOS)-hybrid arrays have become competitive optical detectors for use in ground- and space-based astronomy. Interpixel capacitance (IPC) is one source of error that appears in most CMOS arrays. In this paper, we use a single-pixel-reset method to model IPC. We combine this IPC model with a model for charge diffusion to estimate the total crosstalk on H4RG-10 arrays. Finally, we compare our model results to 55Fe data obtained using an astrometric camera built to test the H4RG-10 B0 generation detectors.