Development of a biological at-risk volume using apparent diffusion coefficient for parotid-sparing radiation therapy planning.

Objectives: Xerostomia toxicity continues to contribute towards a decrease in quality of life in head and neck cancer patients. Diffusion weighted MRI and the associated apparent diffusion coefficient (ADC) may identify the radiosensitive region within the parotid gland (PG). This study retrospectively assesses the feasibility of using percentile threshold values from the ADC map to generate a biological at-risk volume (BRV).

Recurrence formula-based automatic gradient eddy current compensation method for a 0.255 T MRI system.

Gradient coils play a critical role in magnetic resonance imaging (MRI) systems by enabling spatial encoding through generating rapidly switching magnetic fields. However, these time-varying fields induce eddy currents in surrounding conductive structures, leading to gradient field distortions and imaging artifacts. In this study, we propose an automatic eddy current compensation method implemented on a field-programmable gate array (FPGA) platform.

Automatic Magnetic Field Shimming by Spectrum Convergence Method: Evaluation at a 7-T Animal MRI System.

The ultrahigh field magnetic resonance imaging (MRI) superconducting magnets require a high homogeneous magnetic field within the diameter of spherical volume (DSV) to generate high-quality images. Spherical harmonic-based B shimming relies significantly on the fitting process, which can be computationally demanding, particularly when managing multiple shim coils. The study presents an automatic room-temperature shimming approach that iteratively adjusts shim coil currents to enhance magnetic field homogeneity, using the full width at half maximum (FWHM) of the spectrum as a metric.

A cough detection method based on the conformer-BiLSTM model.

Cough is a common symptom of respiratory disease, and its detection is a basic step in cough sound analysis. Manual cough sound segmentation is tedious, subjective, and inefficient. Cough sounds from real-world scenarios can be collected in various environments using different devices, making cough event detection more difficult.

Visual stimulus-evoked blood velocity responses in individual human posterior cerebral arteries measured with dynamic phase-contrast functional MR angiography.

Functional MRI (fMRI) tracks brain activity through the associated hemodynamic changes via neurovascular coupling. Neurons communicate with the microvessels of the parenchyma to initiate a hemodynamic response, and these microvessels then communicate with upstream arterioles and arteries. The role of the larger feeding arteries-far upstream from the site of neuronal activity-in coordinating this response is incompletely understood, yet is important for the interpretation of fMRI.

A novel passive shimming optimization method of MRI magnet based on a PSA-SQP hybrid algorithm.

In Magnetic Resonance Imaging (MRI), achieving a highly uniform main magnetic field (B) is essential for producing detailed images of human anatomy. Passive Shimming (PS) is a technique used to enhance B uniformity by strategically arranging shimming iron pieces inside the magnet bore. Traditionally, PS optimization has been implemented using Linear Programming (LP), posing challenges in balancing field quality with the quantity of iron used for shimming.

Gradient coil design for a 0.23 T NICU MRI system using an improved two-step Target-Field Method with enhanced linearity and compact design.

This study presents an optimized gradient coil design for a miniature 0.23 T MRI system, aimed at improving absolute and relative magnetic field linearity while accommodating various gradient thicknesses. The design uses a two-step optimization approach: the first step uses Tikhonov regularization to solve a linear problem, providing a stable solution, and the second step refines the solution through nonlinear constrained optimization to further enhance field linearity.

Bioelectrics for healthy and food-secure lives: Reply to comments on "Advances in pulsed electric stimuli as a physical method for treating liquid foods".

None.

Portable display devices in healthcare: monocular head-worn displays increase perceptions of clinician warmth relative to tablet computers.

Portable display devices are increasingly important in the healthcare environment. Head-worn displays have efficiency benefits over similar devices, such as tablet computers, with the potential to provide handsfree access to information. However, it is currently unknown whether these devices affect observers' social perceptions of the users.

Phase Locking of 40 Hz Auditory Steady State Responses Is Modulated by Sensory Predictability and Linked to Cerebellar Myelination.

40 Hz auditory steady-state responses (ASSR) can be evoked by brief auditory clicks delivered at 40 Hz. While the neuropharmacology behind the generation of ASSR is well examined, the link between ASSR and microstructural properties of the brain is unclear. Further, whether the 40 Hz ASSR can be manipulated through processes involving top-down control, such as prediction, is currently unknown.

False hope of a single generalisable AI sepsis prediction model: bias and proposed mitigation strategies for improving performance based on a retrospective multisite cohort study.

Objective: To identify bias in using a single machine learning (ML) sepsis prediction model across multiple hospitals and care locations; evaluate the impact of six different bias mitigation strategies and propose a generic modelling approach for developing best-performing models.

Methods: We developed a baseline ML model to predict sepsis using retrospective data on patients in emergency departments (EDs) and wards across nine hospitals. We set model sensitivity at 70% and determined the number of alerts required to be evaluated (number needed to evaluate (NNE), 95% CI) for each case of true sepsis and the number of hours between the first alert and timestamped outcomes meeting sepsis-3 reference criteria (HTS3).

Active and integrated electronic metadevices for future telecommunication circuits.

The rise of data-driven demands calls for terahertz-capable circuits, however, semiconductor devices still face performance limitations above 100 GHz, posing a challenge for wireless networks. Electronic metadevice is a concept inspired by optical metamaterials, which was first demonstrated in the form of switches that could challenge the limitations of traditional semiconductor devices. Here we unveil critical aspects of this technology and demonstrate three-terminal active metadevices, which show promise for the next generation of telecommunication circuits.

Hippocampal subfield volume alterations and associations with severity measures in long COVID and ME/CFS: A 7T MRI study.

Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) patients share similar symptoms including post-exertional malaise, neurocognitive impairment, and memory loss. The neurocognitive impairment in both conditions might be linked to alterations in the hippocampal subfields. Therefore, this study compared alterations in hippocampal subfields of 17 long COVID, 29 ME/CFS patients, and 15 healthy controls (HC).

Exploring in vivo human brain metabolism at 10.5 T: Initial insights from MR spectroscopic imaging.

Introduction: Ultra-high-field magnetic resonance (MR) systems (7 T and 9.4 T) offer the ability to probe human brain metabolism with enhanced precision. Here, we present the preliminary findings from 3D MR spectroscopic imaging (MRSI) of the human brain conducted with the world's first 10.

Eliciting patient preferences and predicting behaviour using Inverse Reinforcement Learning for telehealth use in outpatient clinics.

Introduction: Non-attendance (NA) causes additional burden on the outpatient services due to clinician time and other resources being wasted, and it lengthens wait lists for patients. Telehealth, the delivery of health services remotely using digital technologies, is one promising approach to accommodate patient needs while offering more flexibility in outpatient services. However, there is limited evidence about whether offering telehealth consults as an option can change NA rates, or about the preferences of hospital outpatients for telehealth compared to in-person consults.

Passive shimming of a 3T cryogen-free animal magnetic resonance imaging superconducting magnet with dense shim tray slots and small residual magnetic force.

Passive shimming is widely used in magnetic resonance imaging (MRI) systems due to its excellent efficacy and cost-effectiveness. However, conventional shim tray structures have difficulty in effectively adjusting magnetic field distributions under specific conditions. This limitation can lead to insufficient cancellation of harmonics and result in significant residual forces on the trays, impeding accurate placement of the trays.

Enhancing the viscoelastic properties of bacterial cellulose hydrogels through ultrasonic and enzymatic modification of xyloglucan.

Bacterial cellulose (BC) hydrogels exhibit nanofibril porous network with good viscoelasticity for use as food ingredients and medical materials. Xyloglucan (XG), a hemicellulose with branching residues, can hybridize with BC to improve the hydrogel's extensibility. Thus, modifying the molecular structure of XG can fine-tune the viscoelastic properties of BC hydrogels.

Prediction of perovskite oxygen vacancies for oxygen electrocatalysis at different temperatures.

Efficient catalysts are imperative to accelerate the slow oxygen reaction kinetics for the development of emerging electrochemical energy systems ranging from room-temperature alkaline water electrolysis to high-temperature ceramic fuel cells. In this work, we reveal the role of cationic inductive interactions in predetermining the oxygen vacancy concentrations of 235 cobalt-based and 200 iron-based perovskite catalysts at different temperatures, and this trend can be well predicted from machine learning techniques based on the cationic lattice environment, requiring no heavy computational and experimental inputs. Our results further show that the catalytic activity of the perovskites is strongly correlated with their oxygen vacancy concentration and operating temperatures.

Implementing a two-stage, shim field-calibrated superconducting shimming method on a 7 T cryogen-free small animal MRI magnet.

Ultrahigh field systems (≥ 7 T) can increase the signal-to-noise ratio of magnetic resonance imaging (MRI), improving imaging performance compared to systems with lower fields. However, these enhancements heavily rely on a high B magnetic field homogeneity level, which can be achieved through superconducting shimming. This paper presents a novel two-stage superconducting shimming method designed to achieve precise shimming for a 7 T MRI superconducting magnet.

Complex-valued image reconstruction for compressed sensing MRI using hierarchical constraint.

In Magnetic Resonance Imaging (MRI), the sequential acquisition of raw complex-valued image data in Fourier space, also known as k-space, results in extended examination times. To speed up the MRI scans, k-space data are usually undersampled and processed using numerical techniques such as compressed sensing (CS). While the majority of CS-MRI algorithms primarily focus on magnitude images due to their significant diagnostic value, the phase components of complex-valued MRI images also hold substantial importance for clinical diagnosis, including neurodegenerative diseases.

A hybrid, nonlinear programming approach for optimizing passive shimming in MRI.

Background: In magnetic resonance imaging (MRI), maintaining a highly uniform main magnetic field (B) is essential for producing detailed images of human anatomy. Passive shimming (PS) is a technique used to enhance B uniformity by strategically arranging shimming iron pieces inside the magnet bore. Traditionally, PS optimization has been implemented using linear programming (LP), posing challenges in balancing field quality with the quantity of iron used for shimming.

Verbal memory is linked to average oxygen saturation during sleep, not the apnea-hypopnea index nor novel hypoxic load variables.

Introduction: The apnea-hypopnea index (AHI) is the current diagnostic parameter for diagnosing and estimating the severity of obstructive sleep apnea (OSA). It is, however, poorly associated with the main clinical symptom of OSA, excessive daytime sleepiness, and with the often-seen cognitive decline among OSA patients. To better evaluate OSA severity, novel hypoxic load parameters have been introduced that consider the duration and depth of oxygen saturation drops associated with apneas or hypopneas.

Using Adaptive Imaging Parameters to Improve PEGylated Ultrasmall Iron Oxide Nanoparticles-Enhanced Magnetic Resonance Angiography.

The PEGylated ultrasmall iron oxide nanoparticles (PUSIONPs) exhibit longer blood residence time and better biodegradability than conventional gadolinium-based contrast agents (GBCAs), enabling prolonged acquisitions in contrast-enhanced magnetic resonance angiography (CE-MRA) applications. The image quality of CE-MRA is dependent on the contrast agent concentration and the parameters of the pulse sequences. Here, a closed-form mathematical model is demonstrated and validated to automatically optimize the concentration, echo time (TE), repetition time (TR) and flip angle (FA).

Comprehensive review of deep learning in orthopaedics: Applications, challenges, trustworthiness, and fusion.

Deep learning (DL) in orthopaedics has gained significant attention in recent years. Previous studies have shown that DL can be applied to a wide variety of orthopaedic tasks, including fracture detection, bone tumour diagnosis, implant recognition, and evaluation of osteoarthritis severity. The utilisation of DL is expected to increase, owing to its ability to present accurate diagnoses more efficiently than traditional methods in many scenarios.

Large-scale analysis of structural brain asymmetries during neurodevelopment: Associations with age and sex in 4265 children and adolescents.

Only a small number of studies have assessed structural differences between the two hemispheres during childhood and adolescence. However, the existing findings lack consistency or are restricted to a particular brain region, a specific brain feature, or a relatively narrow age range. Here, we investigated associations between brain asymmetry and age as well as sex in one of the largest pediatric samples to date (n = 4265), aged 1-18 years, scanned at 69 sites participating in the ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) consortium.