Pharmacological modulation of dopamine receptors reveals distinct brain-wide networks associated with learning and motivation in non-human primates.

The neurotransmitter dopamine (DA) has a multifaceted role in healthy and disordered brains through its action on multiple subtypes of dopaminergic receptors. How modulation of these receptors influences learning and motivation by altering intrinsic brain-wide networks remains unclear. Here we performed parallel behavioral and resting-state functional MRI experiments after administration of two different DA receptor antagonists in male and female macaque monkeys.

Iodine-131 radioembolization boosts the immune activation enhanced by icaritin/resiquimod in hepatocellular carcinoma.

Transarterial radioembolization (TARE) is a recommended locoregional strategy for intermediate hepatocellular carcinoma (HCC), whereas, the effect is insufficient to reverse the immunosuppression tumor microenvironment, and the overall benefits for patients remain to be improved. In this study, a multifunctional microsphere (MS) I-ICT/R848-MS is developed to propose an approach combined with TARE, icaritin (ICT) and immune modulator resiquimod (R848). ICT and iodine-131 (I) radiation can induce immunogenic cell death, which, in combination with R848, will boost dendritic cell (DC) maturation.

Improved phosphorus MRSI acquisition through compressed sensing acceleration combined with low-rank reconstruction.

Objectives: Phosphorus-31 magnetic resonance spectroscopic imaging (P-MRSI) is a non-invasive tool for assessing cellular high-energy metabolism in-vivo. However, its acquisition suffers from a low sensitivity, which necessitates large voxel sizes or multiple averages to achieve an acceptable signal-to-noise ratio (SNR), resulting in long scan times.

Materials And Methods: To overcome these limitations, we propose an acquisition and reconstruction scheme for FID-MRSI sequences.

Decoration of Autophagy Detecting Nanoparticle with an Anionic Fluorochrome Enhances Multispectral Characterization of Autophagosome Location and Flux.

Autophagy is a key biological process that has proven extremely difficult to detect noninvasively. To address this, an autophagy detecting nanoparticle (ADN) was recently developed, consisting of an iron oxide nanoparticle decorated with cathepsin-cleavable arginine-rich peptides bound to the near-infrared fluorochrome Cy5.5.

Advancements and challenges in brain cancer therapeutics.

Treating brain tumors requires a nuanced understanding of the brain, a vital and delicate organ. Location, size, tumor type, and surrounding tissue health are crucial in developing treatment plans. This review comprehensively summarizes various treatment options that are available or could be potentially available for brain tumors, including physical therapies (radiotherapy, ablation therapy, photodynamic therapy, tumor-treating field therapy, and cold atmospheric plasma therapy) and non-physical therapies (surgical resection, chemotherapy, targeted therapy, and immunotherapy).

Fast High-Resolution Metabolite Mapping in the rat Brain Using H-FID-MRSI at 14.1 T.

Magnetic resonance spectroscopic imaging (MRSI) enables the simultaneous noninvasive acquisition of MR spectra from multiple spatial locations inside the brain. Although H-MRSI is increasingly used in the human brain, it is not yet widely applied in the preclinical setting, mostly because of difficulties specifically related to very small nominal voxel size in the rat brain and low concentration of brain metabolites, resulting in low signal-to-noise ratio (SNR). In this context, we implemented a free induction decay H-MRSI sequence (H-FID-MRSI) in the rat brain at 14.

Optimized MR pulse sequence for high-resolution brain 3D-T1ρ mapping with weighted spin-lock acquisitions.

Purpose: To implement and evaluate the feasibility of brain spin-lattice relaxation in the rotating frame (T1ρ) mapping using a novel optimized pulse sequence that incorporates weighted spin-lock acquisitions, enabling high-resolution three-dimensional (3D) mapping.

Methods: The optimized variable flip-angle framework, previously proposed for knee T1ρ mapping, was enhanced by integrating weighted spin-lock acquisitions. This strategic combination significantly boosts signal-to-noise ratio (SNR) while reducing data acquisition time, facilitating high-resolution 3D-T1ρ mapping of the brain.

Hypothalamic volume is associated with age, sex and cognitive function across lifespan: a comparative analysis of two large population-based cohort studies.

Background: Emerging findings indicate that the hypothalamus, the body's principal homeostatic centre, plays a crucial role in modulating cognition, but comprehensive population-based studies are lacking.

Methods: We used cross-sectional data from the Rhineland Study (N = 5812, 55.2 ± 13.

On the origin of MTF reduction in grating-based x-ray differential phase contrast CT imaging.

Background: The complementary absorption contrast CT (ACT) and differential phase contrast CT (DPCT) can be generated simultaneously from an x-ray computed tomography (CT) imaging system incorporated with grating interferometer. However, it has been reported that ACT images exhibit better spatial resolution than DPCT images. By far, the primary cause of such discrepancy remains unclear.

Assessing the stability of photon-counting CT: insights from a 2-year longitudinal study.

Objective: Among the advancements in computed tomography (CT) technology, photon-counting computed tomography (PCCT) stands out as a significant innovation, providing superior spectral imaging capabilities while simultaneously reducing radiation exposure. Its long-term stability is important for clinical care, especially longitudinal studies, but is currently unknown. This study sets out to comprehensively analyze the long-term stability of a first-generation clinical PCCT scanner.

Acquisition of musical skills and abilities in older adults-results of 12 months of music training.

Background: Older adults can acquire new skills across different domains. Practicing a musical instrument has been identified as a promising activity for improving cognition, promoting well-being, and inducing brain plasticity in older individuals. However, the mechanisms of these changes are still poorly understood.

Hemodynamic relationship with angioarchitecture of cerebral arteriovenous malformation and changes after embolization: a pilot study by 4D flow MR.

Background: The hemodynamics of cerebral arteriovenous malformation (cAVM) is difficult to evaluate with conventional imaging or clinical grading. The aim of this study is to: (I) investigate the association between the angioarchitecture and hemodynamic parameters in cAVM based on 4-dimentional flow magnetic resonance (4D flow MR); (II) quantify flow changes during follow-up after embolization and explore the potential of flow-guided staged embolization.

Methods: Twenty-one patients with digital subtraction angiography (DSA)-diagnosed cAVM were prospectively enrolled in a tertiary hospital consecutively from April 2022 to January 2024 for a cohort study.

Assessing regional homogeneity and cognitive function alterations in pediatric brain tumor patients: a resting-state functional magnetic resonance imaging study.

Background: Cognitive impairment mechanisms in children with preoperative brain tumors are not well understood. This study aimed to determine the correlation between the changes of resting-state functional magnetic resonance imaging (rs-fMRI) and the fourth edition of the Wechsler Intelligence Scale for Children (WISC-IV) in patients with brain tumors before surgery and in healthy controls (HCs).

Methods: rs-fMRI data were acquired using 3-T magnetic resonance imaging (MRI) scanners for 21 patients with pediatric brain tumor and 19 age- and gender-matched HCs.

Greater baseline cortical atrophy in the dorsal attention network predicts faster clinical decline in Posterior Cortical Atrophy.

Background: Posterior Cortical Atrophy (PCA) is a clinical syndrome characterized by progressive visuospatial and visuoperceptual impairment. As the neurodegenerative disease progresses, patients lose independent functioning due to the worsening of initial symptoms and development of symptoms in other cognitive domains. The timeline of clinical progression is variable across patients, and the field currently lacks robust methods for prognostication.

Differential late-stage face processing in autism: a magnetoencephalographic study of fusiform gyrus activation.

Background: Autism is associated with alterations of social communication, such as during face-to-face interactions. This study aimed to probe face processing in autistics with normal IQ utilizing magnetoencephalography to examine event-related fields within the fusiform gyrus during face perception.

Methods: A case-control cohort of 22 individuals diagnosed with autism and 20 age-matched controls (all male, age 29.

An implemented predictive coding model of lexico-semantic processing explains the dynamics of univariate and multivariate activity within the left ventromedial temporal lobe during reading comprehension.

During language comprehension, the larger neural response to unexpected versus expected inputs is often taken as evidence for predictive coding-a specific computational architecture and optimization algorithm proposed to approximate probabilistic inference in the brain. However, other predictive processing frameworks can also account for this effect, leaving the unique claims of predictive coding untested. In this study, we used MEG to examine both univariate and multivariate neural activity in response to expected and unexpected inputs during word-by-word reading comprehension.

Model-based CBCT scatter correction with dual-layer flat-panel detector.

Background: Recently, the popularity of dual-layer flat-panel detector (DL-FPD) based dual-energy cone-beam CT (CBCT) imaging has been increasing. However, the image quality of dual-energy CBCT remains constrained by the Compton scattered x-ray photons.

Purpose: The objective of this study is to develop a novel scatter correction method, named e-Grid, for DL-FPD based CBCT imaging.

Exploring the Effects of Prefrontal Transcranial Direct Current Stimulation on Brain Metabolites: A Concurrent tDCS-MRS Study.

Transcranial Direct Current Stimulation (tDCS) is a non-invasive brain stimulation technique used to modulates cortical brain activity. However, its effects on brain metabolites within the dorsolateral prefrontal cortex (DLPFC), a crucial area targeted for brain stimulation in mental disorders, remain unclear. This study aimed to investigate whether prefrontal tDCS over the left and right DLPFC modulates levels of key metabolites, including gamma-aminobutyric acid (GABA), glutamate (Glu), glutamine/glutamate (Glx), N-acetylaspartate (NAA), near to the target region and to explore potential sex-specific effects on these metabolite concentrations.

Near-infrared diffuse optical characterization of human thyroid using ultrasound-guided hybrid time-domain and diffuse correlation spectroscopies.

Thyroid vascularization and hemodynamics become altered in thyroid pathologies and could thus inform diagnostics, therapy planning, and follow-up. However, the current non-invasive monitoring methods available in clinics lack the necessary sensitivity and/or are impractical for large-scale deployment. As a step towards proposing a new modality, we applied the first platform, to our knowledge, designed to do simultaneous measurements of neck anatomy and thyroid microvascular hemodynamics and metabolism in a single probe placement, integrating state-of-the-art near-infrared spectroscopy techniques and clinical ultrasound.

ECCENTRIC: A fast and unrestrained approach for high-resolution in vivo metabolic imaging at ultra-high field MR.

A novel method for fast and high-resolution metabolic imaging, called ECcentric Circle ENcoding TRajectorIes for Compressed sensing (ECCENTRIC), has been developed at 7 Tesla MRI. ECCENTRIC is a non-Cartesian spatial-spectral encoding method designed to accelerate magnetic resonance spectroscopic imaging (MRSI) with high signal-to-noise at ultra-high field. The approach provides flexible and random sampling of the Fourier space without temporal interleaving to improve spatial response function and spectral quality.

Leveraging Stacked Classifiers for Multi-task Executive Function in Schizophrenia Yields Diagnostic and Prognostic Insights.

Cognitive impairment is a central characteristic of schizophrenia. Executive functioning (EF) impairments are often seen in mental disorders, particularly schizophrenia, where they relate to adverse outcomes. As a heterogeneous construct, how specifically each dimension of EF to characterize the diagnostic and prognostic aspects of schizophrenia remains opaque.

In vivo evidence for cell body loss in cortical lesions in people with multiple sclerosis.

Objective: To quantify alterations in soma and neurite density imaging measures within and surrounding cortical lesions in people with multiple sclerosis using in vivo high-gradient diffusion MRI.

Methods: In this cross-sectional study, 41 people with multiple sclerosis and 34 age- and sex-matched healthy controls underwent 3 T high-gradient diffusion MRI. Cortical lesions were segmented on artificial intelligence-enabled double inversion recovery images.

Versatile MRI acquisition and processing protocol for population-based neuroimaging.

Neuroimaging has an essential role in studies of brain health and of cerebrovascular and neurodegenerative diseases, requiring the availability of versatile magnetic resonance imaging (MRI) acquisition and processing protocols. We designed and developed a multipurpose high-resolution MRI protocol for large-scale and long-term population neuroimaging studies that includes structural, diffusion-weighted and functional MRI modalities. This modular protocol takes almost 1 h of scan time and is, apart from a concluding abdominal scan, entirely dedicated to the brain.