Prenatal Alcohol Exposure Disrupts Performance in a Differential Reinforcement of Low Rates Task Specifically in Adolescent Male Rats.

Prenatal alcohol exposure (PAE) can lead to a wide range of adverse effects in humans, including impaired self-control and increased impulsive behavior. Deficits in self-control can interfere with academic performance and have lasting impacts. In the present study, a rodent model of PAE was used to assess impulsivity through operant conditioning.

: A 3D printing method of fabricating patient-specific deformable CT phantoms for respiratory motion applications.

All in-vivo medical imaging is impacted by patient motion, especially respiratory motion, which has a significant influence on clinical workflows in diagnostic imaging and radiation therapy. Many technologies such as motion artifact reduction and tumor tracking algorithms have been developed to compensate for respiratory motion during imaging. To assess these technologies, respiratory motion phantoms (RMPs) are required as preclinical testing environments, for instance, in computed tomography (CT).

Lifelike phantoms for assessing clinical image quality and dose reduction capabilities of a deep learning CT reconstruction algorithm.

Deep learning CT reconstruction (DLR) has become increasingly popular as a method for improving image quality and reducing radiation exposure. Due to their nonlinear nature, these algorithms result in resolution and noise performance which are object-dependent. Therefore, traditional CT phantoms, which lack realistic tissue morphology, have become inadequate for assessing clinical imaging performance.

Hybrid spectral CT system with clinical rapid kVp-switching x-ray tube and dual-layer detector for improved iodine quantification.

Spectral computed tomography (CT) is a powerful diagnostic tool offering quantitative material decomposition results that enhance clinical imaging by providing physiologic and functional insights. Iodine, a widely used contrast agent, improves visualization in various clinical contexts. However, accurately detecting low-concentration iodine presents challenges in spectral CT systems, particularly crucial for conditions like pancreatic cancer assessment.

Impact of scatter radiation on spectral quantification performance of first- and second-generation dual-layer spectral computed tomography.

Objective: To assess the impact of scatter radiation on quantitative performance of first and second-generation dual-layer spectral computed tomography (DLCT) systems.

Method: A phantom with two iodine inserts (1 and 2 mg/mL) configured to intentionally introduce high scattering conditions was scanned with a first- and second-generation DLCT. Collimation widths (maximum of 4 cm for first generation and 8 cm for second generation) and radiation dose levels were varied.

Patient-derived PixelPrint phantoms for evaluating clinical imaging performance of a deep learning CT reconstruction algorithm.

. Deep learning reconstruction (DLR) algorithms exhibit object-dependent resolution and noise performance. Thus, traditional geometric CT phantoms cannot fully capture the clinical imaging performance of DLR.

Prenatal alcohol exposure alters expression of genes involved in cell adhesion, immune response, and toxin metabolism in adolescent rat hippocampus.

Prenatal alcohol exposure (PAE) can result in mild to severe consequences for children throughout their lives, with this range of symptoms referred to as Fetal Alcohol Spectrum Disorders (FASD). These consequences are thought to be linked to changes in gene expression and transcriptional programming in the brain, but the identity of those changes, and how they persist into adolescence are unclear. In this study, we isolated RNA from the hippocampus of adolescent rats exposed to ethanol during prenatal development and compared gene expression to controls.

Reproducible spectral CT thermometry with liver-mimicking phantoms for image-guided thermal ablation.

. Evaluate the reproducibility, temperature tolerance, and radiation dose requirements of spectral CT thermometry in tissue-mimicking phantoms to establish its utility for non-invasive temperature monitoring of thermal ablations..

Patient-derived PixelPrint phantoms for evaluating clinical imaging performance of a deep learning CT reconstruction algorithm.

Objective: Deep learning reconstruction (DLR) algorithms exhibit object-dependent resolution and noise performance. Thus, traditional geometric CT phantoms cannot fully capture the clinical imaging performance of DLR. This study uses a patient-derived 3D-printed PixelPrint lung phantom to evaluate a commercial DLR algorithm across a wide range of radiation dose levels.

Reproducible spectral CT thermometry with liver-mimicking phantoms for image-guided thermal ablation.

Objectives: Evaluate the reproducibility, temperature sensitivity, and radiation dose requirements of spectral CT thermometry in tissue-mimicking phantoms to establish its utility for non-invasive temperature monitoring of thermal ablations.

Materials And Methods: Three liver mimicking phantoms embedded with temperature sensors were individually scanned with a dual-layer spectral CT at different radiation dose levels during heating and cooling (35 to 80 °C). Physical density maps were reconstructed from spectral results using a range of reconstruction parameters.

Quantitative positron emission tomography imaging in the presence of iodinated contrast media using electron density quantifications from dual-energy computed tomography.

Purpose: As preparation for future positron emission tomography (PET)/dual-energy computed tomography (DECT)T imaging modality and new possible clinical applications, the study aimed to evaluate the utility of clinically available spectral results from a DECT system for improving attenuation corrections of PET acquisitions in the presence of iodinated contrast media. The dependence of the accuracy of PET quantification values, reconstructed with conventional and spectral-based attenuation corrections, was examined as a function of the amount of iodine content and x-ray radiation exposure.

Methods: Measurements were performed on commercial PET/CT and DECT systems, using a semi-anthropomorphic phantom with seven centrifuge tubes in its bore.

From adolescence to late aging: A comprehensive review of social behavior, alcohol, and neuroinflammation across the lifespan.

The passage of time dictates the pace at which humans and other organisms age but falls short of providing a complete portrait of how environmental, lifestyle and underlying biological processes contribute to senescence. Two fundamental features of the human experience that change dramatically across the lifespan include social interactions and, for many, patterns of alcohol consumption. Rodent models show great utility for understanding complex interactions among aging, social behavior and alcohol use and abuse, yet little is known about the neural changes in late aging that contribute to the natural decline in social behavior.

Late aging-associated increases in L-DOPA-induced dyskinesia are accompanied by heightened neuroinflammation in the hemi-parkinsonian rat.

Aging is a primary risk factor for the development of Parkinson's disease (PD), and aging differentially predicts the incidence of L-DOPA-induced dyskinesia (LID). The goal of this work was to establish whether late aging-associated exacerbation of LID would be related to neuroinflammation in the hemi-parkinsonian rat. Two studies were conducted in which adult (3 months) and aged (18 months) male Fischer 344 rats bearing unilateral 6-hydroxydopamine lesions of the medial forebrain bundle were injected acutely with vehicle or L-DOPA (6 mg/kg).

PennPET Explorer: Design and Preliminary Performance of a Whole-Body Imager.

We report on the development of the PennPET Explorer whole-body imager. The PennPET Explorer is a multiring system designed with a long axial field of view. The imager is scalable and comprises multiple 22.

Impact of housing conditions on social behavior, neuroimmune markers, and oxytocin receptor expression in aged male and female Fischer 344 rats.

Aging is associated with a substantial decline in social behavior, whereas positive social interaction can improve overall health in aged individuals. In laboratory rodents, manipulations of the social environment across the lifespan have been shown to affect social behavior. Therefore, we examined the effects of long-term (5-6 weeks) housing conditions (alone, with one adult, or with two adults) on social behavior and the expression of neuroinflammation-related genes as well as oxytocin receptor (OXTR) gene expression in brain areas associated with social behavior regulation in aged male and female Fischer (F) 344 rats.

Late aging alters behavioral sensitivity to ethanol in a sex-specific manner in Fischer 344 rats.

Responsiveness to ethanol (EtOH) differs as a function of age. Adolescent rodents are less sensitive than adults to the sedative effects of EtOH, whereas they show enhanced sensitivity to EtOH-induced social facilitation. Late aging is associated with a natural decline in social behavior and aging-related peculiarities in sensitivity to EtOH have been largely unexplored.

Optimization-Based Image Reconstruction From Low-Count, List-Mode TOF-PET Data.

Objective: We investigate an optimization-based approach to image reconstruction from list-mode data in digital time-of-flight (TOF) positron emission tomography (PET) imaging.

Method: In the study, the image to be reconstructed is designed as a solution to a convex, non-smooth optimization program, and a primal-dual algorithm is developed for image reconstruction by solving the optimization program. The algorithm is first applied to list-mode TOF-PET data of a typical count level from physical phantoms and a human subject.

Stereological Analysis of Microglia in Aged Male and Female Fischer 344 Rats in Socially Relevant Brain Regions.

Aging is associated with a substantial decline in the expression of social behavior as well as increased neuroinflammation. Since immune activation and subsequent increased expression of cytokines can suppress social behavior in young rodents, we examined age and sex differences in microglia within brain regions critical to social behavior regulation (PVN, BNST, and MEA) as well as in the hippocampus. Adult (3-month) and aged (18-month) male and female F344 (N = 26, n = 5-8/group) rats were perfused and Iba-1 immunopositive microglia were assessed using unbiased stereology and optical density.

Analysis of c-Fos induction in response to social interaction in male and female Fisher 344 rats.

Sex differences in the expression of social behavior are typically apparent in adolescent and adult rats. While the neurobiology underlying juvenile social play behavior has been well characterized, less is known about discrete brain regions involved in adult responsiveness to a same sex peer. Furthermore, whether adult males and females differ in their responsiveness to a social interaction in terms of neuronal activation indexed via immediate early gene (IEG) expression remains to be determined.

Scatter Correction with Combined Single-Scatter Simulation and Monte Carlo Simulation Scaling Improved the Visual Artifacts and Quantification in 3-Dimensional Brain PET/CT Imaging with O-Gas Inhalation.

In 3-dimensional PET/CT imaging of the brain with O-gas inhalation, high radioactivity in the face mask creates cold artifacts and affects the quantitative accuracy when scatter is corrected by conventional methods (e.g., single-scatter simulation [SSS] with tail-fitting scaling [TFS-SSS]).

Investigation of optimization-based reconstruction with an image-total-variation constraint in PET.

Interest remains in reconstruction-algorithm research and development for possible improvement of image quality in current PET imaging and for enabling innovative PET systems to enhance existing, and facilitate new, preclinical and clinical applications. Optimization-based image reconstruction has been demonstrated in recent years of potential utility for CT imaging applications. In this work, we investigate tailoring the optimization-based techniques to image reconstruction for PET systems with standard and non-standard scan configurations.