Constrained optimized water suppression for H MR spectroscopy.

Purpose: Water suppression is a necessary component to standard MR spectroscopy experiments due to the approximately 5000-10 000-fold higher water concentration and signal intensity compared with that of the metabolites and macromolecules of interest. Here, a novel algorithm referred to as constrained optimized water suppression (COWS) was developed, which enables generation of effective water suppression modules with an arbitrary number of radiofrequency (RF) pulses, and flexibly accommodates minimum durations between pulses, minimum total module duration, and maximum flip angles.

Methods: We use the COWS algorithm to create a water-suppression module with seven pulses, the same number of RF pulses as typical VAPOR7, at a reduced module duration of 236 ms, referred to as COWS(7;236), as well as one at the typical VAPOR duration but with an increased number of RF pulses, referred to as COWS(12;626).

Enhancing Left Ventricular Assist Device Usability: A Comparative Simulation Study of CorWave and HeartMate 3 Peripherals.

Left ventricular assist devices (LVADs) improve outcomes but often compromise quality of life (QoL) due to usability issues with wearables. This study compared the usability of CorWave LVAD (CW) peripherals prototypes to HeartMate 3 LVAD (HM3) peripherals through a cross-sectional, simulation-based approach involving LVAD-naive laypeople, and heart transplantation (HTX) patients post-LVAD support. Simulations encompassed six tasks, measuring initial success rates, duration to success, pump-off time, and a post-scenario survey.

Time Course of Plasma Proteomic and Oxylipin Changes Induced by LPS Challenge and Modulated by Antioxidant Supplementation in a Randomized Controlled Trial.

Systemic molecular responses to pathogen-associated molecular patterns and their modulation by antioxidants are poorly understood in humans. Here, we present a two-stage clinical interventional study in healthy humans challenged with lipopolysaccharide. In the first step, the kinetics of inflammatory modulators within 8 h were investigated by plasma proteomics and lipidomics.

Measurement of orthodontic tooth movement in lower anterior teeth by means of magnetic resonance imaging- a prospective pilot study.

Background: During orthodontic treatment, the risk of gingival recession may increase, especially in the mandibular anterior region due to thin alveolar bone. This prospective pilot study aimed to develop a standardized evaluation method based on magnetic resonance imaging (MRI) for analysing tooth movements and tissue dimensions and to investigate the impact on periodontal parameters during orthodontic levelling.

Materials And Methods: Participants aged 12 to 18 with lower jaw crowding underwent MRI scans before (T0) and five months into orthodontic treatment (T1).

Alzheimer's disease neuropathological change in younger individuals with IDH-mutant glioma.

Background: With aging populations, the incidence of brain tumors and neurodegenerative diseases is rising. Recently, Alzheimer's disease neuropathological change (ADNC) has been documented in the tumor-adjacent cortex of 50% of patients with glioblastoma, with isolated hyperphosphorylated tau (pTau) deposits already present in younger individuals. This study extends ADNC screening to younger patients with IDH-mutant glioma, focusing on pTau and amyloid beta (Abeta) deposits, microglial activation, and amyloid precursor protein (APP) expression in the context of cortical tumor cell infiltration.

T Relaxation Time for the Prediction of Renal Transplant Dysfunction.

Quantitative magnetic resonance imaging (MRI) is emerging as a non-invasive tool to measure tissue scarring in renal allografts. However, whether prolonged T relaxation time results in lower transplant survival rates is unknown. This retrospective cohort study analyzed the capability to predict renal allograft dysfunction based on median T time.

Optoretinography reveals rapid rod photoreceptor movement upon photoisomerization.

Rod photoreceptors are essential for vision under dim light conditions. The onset of rod-mediated vision is marked by the isomerization of rhodopsin. Here we demonstrate that human and rodent rods undergo a minute and rapid contraction of their outer segments immediately upon photoisomerization.

Expandable grid, a simple, readily available and precise technique for intraoperative stereotactic real-time imaging.

Introduction: Pre- and postoperative imaging constitutes a firm brick in planning and steering accurate stereotactic procedures. The availability of intraoperative control measures, e.g.

Association Between Dementia and Optical Coherence Tomography Scan Quality.

It is generally assumed that dementia affects the quality of optical coherence tomography (OCT) scans. However, the magnitude of this effect and its independence from other factors require further clarification. In this cross-sectional study, our aim was to evaluate the association between cognitive impairment and OCT scan quality, adjusting for key confounders, in a multiethnic cohort.

A Comparative In Vitro Study on Heat Generation with Static Guided and Conventional Implant Bed Preparation Using Stainless Steel Twist Drills and a Standardized Bovine Model.

The aim of this in vitro study was to evaluate the differences in heat generation across the drilling techniques, depths, and irrigation conditions of static computer-assisted implant surgery (S-CAIS) and conventional implant preparation (CIP) using a standardized bone model for comparative investigation. A total of 240 automated intermittent experimental procedures of 10 and 12 mm drilling depths were performed during S-CAIS and CIP using stainless steel twist drills of three drill diameters (2.2, 2.

Energy dependence of the response of X-ray multimeter for radiation qualities in mammography.

Ensuring comprehensive quality control of breast imaging systems involving ionizing radiation like mammography and tomosynthesis is crucial for high diagnostic confidence and maintaining an acceptable patient dose. This requires accurate dosimetric measurements, including air kerma, half-value layer (HVL), and tube voltage as key quantities. Ionization chambers or semiconductor-based X-ray multimeters (XMMs) are used to measure these parameters, with XMMs also displaying tube voltage in one exposure in addition to numerous other parameters.

Introduction to the Biophotonics Congress 2024 feature issue.

We present a feature issue containing 14 papers based on a subset of the studies presented during the Optica Biophotonics Congress: Biomedical Optics held on April 7-10, 2024, in Ft. Lauderdale, Florida, USA.

Staying in Place: In Vitro Comparison of Extracorporeal Membrane Oxygenation Cannula Fixation for Dislodgment Prevention.

: Secure large-bore cannula insertion is critical for effective extracorporeal membrane oxygenation (ECMO), as inadequate fixation can lead to complications such as infection, dislodgment, and life-threatening events. With inconsistent guidelines for ECMO line management, this study compares the effectiveness of traditional suture fixation to an adhesive securement method in the prevention of ECMO cannula dislodgment using an in vitro model. : Porcine skin and muscle tissue sections were prepared and mounted in a custom holder.

Clinician-driven automated data preprocessing in nuclear medicine AI environments.

Background: Artificial Intelligence (AI) approaches in clinical science require extensive data preprocessing (DP) steps prior to building AI models. Establishing DP pipelines is a non-trivial task, mainly driven by purely mathematical rules and done by data scientists. Nevertheless, clinician presence shall be paramount at this step.

Spline Baseline Model Flexibility Independently Affects the Accuracy and Precision of In Vivo Proton Magnetic Resonance Spectral Fitting in a Metabolite-Specific Manner Not Visually Predicted by Fit Residuals.

In vivo proton magnetic resonance spectroscopy (H-MRS) data often exhibit baselines or low-amplitude signal variations resulting from residual water, imperfectly suppressed lipids, low-amplitude metabolites not considered for fitting, and other features not represented in a basis set. While multitudinous approaches exist to model these baselines in H-MR spectral analysis, many continue to lack systematic validation against varied and realistic ground-truth standards. Here, we compare the accuracy (error mean) and precision (error standard deviation) of metabolite scaling estimates by linear combination modeling (LCM) spectral fitting accounting for spectral baselines via smoothed cubic splines at 50 different combinations of fixed knot interval and smoothing weight, either with or without additionally simulated Gaussian basis signals to separately model spectral macromolecules.

Enhancing Blood-Brain Barrier Penetration Prediction by Machine Learning-Based Integration of Novel and Existing, In Silico and Experimental Molecular Parameters from a Standardized Database.

Predicting blood-brain barrier (BBB) penetration is crucial for developing central nervous system (CNS) drugs, representing a significant hurdle in successful clinical phase I studies. One of the most valuable properties for this prediction is the polar surface area (PSA). However, molecular structures are missing geometric optimization, which, together with lack of standardization, leads to variations in calculation.

Longitudinal analysis of retinal and choriocapillaris in patients with multiple sclerosis: a 3-year study.

Objectives: This study investigated the longitudinal progression of retinal structure and microvasculature over 3 years in patients with relapsing-remitting multiple sclerosis (RRMS) using optical coherence tomography (OCT) and OCT angiography (OCTA). It also explored the correlation between these changes and the Expanded Disability Status Scale (EDSS) scores.

Methods: In this prospective, longitudinal study, we enrolled 66 patients with RRMS without history of optic neuritis and 124 healthy controls.

Flow and ischemic changes in retina and choroid across diabetic retinopathy spectrum: a SS-OCTA study.

Purpose: To examine changes in retinal and choroidal vasculature in diabetes mellitus across the range of diabetic retinopathy (DR) severities using optical coherence tomography angiography (OCTA) and compare the patterns of vascular changes.

Methods: We conducted a cross-sectional study enrolling 296 patients (498 eyes) with diabetes mellitus. Swept-Source OCT Angiography variables in both retina and choroid, including perfusion density (PD), vessel density (VD), large vessel density (LVD) in both superficial and deep layer of retina and CC flow voids (FD) density of the choroid were quantified.

Axonal regeneration and innervation ratio following supercharged end-to-side nerve transfer.

Introduction: Peripheral nerve injuries often result in incomplete recovery, particularly after the occurrence of proximal lesions, owing to the extended reinnervation time as well as consequent reductions in the regeneration supportive factors and muscle recovery potential. In these cases, supercharged end-to-side (SETS) nerve transfers preserve the continuity of the original nerves while facilitating additional axonal support to mitigate muscle atrophy. This approach enhances functional recovery and has been demonstrated to be effective in both preclinical models and clinical settings.

Image Quality in Adaptive Optics Optical Coherence Tomography of Diabetic Patients.

: An assessment of the retinal image quality in adaptive optics optical coherence tomography (AO-OCT) is challenging. Many factors influence AO-OCT imaging performance, leading to greatly varying imaging results, even in the same subject. The aim of this study is to introduce quantitative means for an assessment of AO-OCT image quality and to compare these with parameters retrieved from the pyramid wavefront sensor of the system.

Phase-restoring subpixel image registration: enhancing motion detection performance in Fourier-domain optical coherence tomography.

Phase-sensitive Fourier-domain optical coherence tomography (FD-OCT) enables , label-free imaging of cellular movements with detection sensitivity down to the nanometer scale, and it is widely employed in emerging functional imaging modalities, such as optoretinography (ORG), Doppler OCT, and optical coherence elastography. However, when imaging tissue dynamics , inter-frame displacement introduces decorrelation noise that compromises motion detection performance, particularly in terms of sensitivity and accuracy. Here, we demonstrate that the displacement-related decorrelation noise in FD-OCT can be accurately corrected by restoring the initial sampling points using our proposed Phase-Restoring Subpixel Image Registration (PRESIR) method.

Complex conjugate removal in optical coherence tomography using phase aware generative adversarial network.

Significance: Current methods for complex conjugate removal (CCR) in frequency-domain optical coherence tomography (FD-OCT) often require additional hardware components, which increase system complexity and cost. A software-based solution would provide a more efficient and cost-effective alternative.

Aim: We aim to develop a deep learning approach to effectively remove complex conjugate artifacts (CCAs) from OCT scans without the need for extra hardware components.

Development of a label-free, functional, molecular and structural imaging system combining optical coherence tomography and Raman spectroscopy for in vivo measurement of rat retina.

In vivo access to molecular information of retinal tissue is considered to play a critical role in enabling early diagnosis of ophthalmic and neurodegenerative diseases. The current gold standard of retina imaging, optical coherence tomography and angiography provides only the retinal morphology and blood perfusion, missing the full spectrum of molecular information. Raman spectroscopy addresses this gap while keeping the investigation non-invasive and label-free.

Association of pregnancy with tumour progression in patients with glioma.

Background: A significant proportion of women in reproductive age are diagnosed with diffuse gliomas, resulting in the need to address the safety of pregnancy in patient consultation. However, data on glioma progression after and during pregnancy are sparse and controversial.

Methods: Female adult patients in their reproductive years (≥18 years and <46 years) with histological diagnosis of glioma between 01/01/2000 and 01/12/2019 from 2 academic centers have been included in the study.

synMARSS-An End-To-End Platform for the Parametric Generation of Synthetic In Vivo Magnetic Resonance Spectra.

Synthetic magnetic resonance spectra (MRS) are mathematically generated spectra which can be used to investigate the assumptions of data analysis strategies, optimize experimental design, and as training data for the development and validation of machine learning tools. In this work, we extend Magnetic Resonance Spectrum Simulator (MARSS), a popular MRS basis set simulation tool, to be able to generate synthetic spectra for an arbitrary MRS sequence. The extension, referred to as synMARSS, converts a basis set as well as a set of NMR, tissue-related and additional sequence parameters into high-quality synthetic spectra via a parametric model.