Different sodium concentrations of noncancerous and cancerous prostate tissue seen on MRI using an external coil.

Background: Sodium (Na) MRI of prostate cancer (PCa) is a novel but underdocumented technique conventionally acquired using an endorectal coil. These endorectal coils are associated with challenges (e.g.

Parameter optimization for proton density fat fraction quantification in skeletal muscle tissue at 7 T.

Objective: To establish an image acquisition and post-processing workflow for the determination of the proton density fat fraction (PDFF) in calf muscle tissue at 7 T.

Materials And Methods: Echo times (TEs) of the applied vendor-provided multi-echo gradient echo sequence were optimized based on simulations of the effective number of signal averages (NSA*). The resulting parameters were validated by measurements in phantom and in healthy calf muscle tissue (n = 12).

Sodium quantification in skeletal muscle: comparison between Cartesian gradient-echo and radial ultra-short echo time Na MRI techniques.

Background: Clinical magnetic resonance imaging (MRI) studies often use Cartesian gradient-echo (GRE) sequences with ~2-ms echo times (TEs) to monitor apparent total sodium concentration (aTSC). We compared Cartesian GRE and ultra-short echo time three-dimensional (3D) radial-readout sequences for measuring skeletal muscle aTSC.

Methods: We retrospectively evaluated 211 datasets from 112 volunteers aged 62.

Recent technical developments and clinical research applications of sodium (Na) MRI.

Sodium is an essential ion that plays a central role in many physiological processes including the transmembrane electrochemical gradient and the maintenance of the body's homeostasis. Due to the crucial role of sodium in the human body, the sodium nucleus is a promising candidate for non-invasively assessing (patho-)physiological changes. Almost 10 years ago, Madelin et al.

Multi-echo-based fat artifact correction for CEST MRI at 7 T.

Purpose: CEST MRI is influenced by fat signal, which can reduce the apparent CEST contrast or lead to pseudo-CEST effects. Our goal was to develop a fat artifact correction based on multi-echo fat-water separation that functions stably for 7 T knee MRI data.

Methods: Our proposed algorithm utilizes the full complex data and a phase demodulation with an off-resonance map estimation based on the Z-spectra prior to fat-water separation to achieve stable fat artifact correction.

MRI of Potassium and Sodium Enables Comprehensive Analysis of Ion Perturbations in Skeletal Muscle Tissue After Eccentric Exercise.

Objectives: The aims were to investigate if potassium ( 39 K) magnetic resonance imaging (MRI) can be used to analyze changes in the apparent tissue potassium concentration (aTPC) in calf muscle tissue after eccentric exercise and in delayed-onset muscle soreness, and to compare these to corresponding changes in the apparent tissue sodium concentration (aTSC) measured with sodium ( 23 Na) MRI.

Materials And Methods: Fourteen healthy subjects (7 female, 7 male; 25.0 ± 2.

Sodium and quantitative hydrogen parameter changes in muscle tissue after eccentric exercise and in delayed-onset muscle soreness assessed with magnetic resonance imaging.

The objective of the current study was to assess sodium ( Na) and quantitative proton ( H) parameter changes in muscle tissue with magnetic resonance imaging (MRI) after eccentric exercise and in delayed-onset muscle soreness (DOMS). Fourteen participants (mean age: 25 ± 4 years) underwent Na/ H MRI of the calf muscle on a 3-T MRI system before exercise (t0), directly after eccentric exercise (t1), and 48 h postintervention (t2). In addition to tissue sodium concentration (TSC), intracellular-weighted sodium (ICwS) signal was acquired using a three-dimensional density-adapted radial projection readout with an additional inversion recovery preparation module.

Muscle perfusion and the effect of compression garments in delayed-onset muscle soreness assessed with arterial spin labeling magnetic resonance imaging.

Background: There is limited information about perfusion in exercise-induced muscle injuries such as delayed-onset muscle soreness (DOMS) and the effect of compression garments as a therapeutic strategy during the regeneration phase. The purpose of this prospective, explorative study was to evaluate muscle perfusion in DOMS and to assess the effect of compression garments at resting conditions and during DOMS by magnetic resonance (MR) arterial spin labeling (ASL).

Methods: DOMS was induced from 03/2021 to 04/2021 using an eccentric and plyometric exercises targeting the calf muscles in 14 volunteers.

Assessing muscle-specific potassium concentrations in human lower leg using potassium magnetic resonance imaging.

Noninvasively assessing tissue potassium concentrations (TPCs) using potassium magnetic resonance imaging ( K MRI) could give valuable information on physiological processes connected to various pathologies. However, because of inherently low K MR image resolution and strong signal blurring, a reliable measurement of the TPC is challenging. The aim of this work was to investigate the feasibility of a muscle-specific TPC determination with a focus on the influence of a varying residual quadrupolar interaction in human lower leg muscles.

Quantitative 7T sodium magnetic resonance imaging of the human brain using a 32-channel phased-array head coil: Application to patients with secondary progressive multiple sclerosis.

Apparent tissue sodium concentrations (aTSCs) determined by Na brain magnetic resonance imaging (MRI) have the potential to serve as a biomarker in pathologies such as multiple sclerosis (MS). However, the quantification is hindered by the intrinsically low signal-to-noise ratio of Na MRI. The purpose of this study was to improve the accuracy and reliability of quantitative Na brain MRI by implementing a dedicated postprocessing pipeline and to evaluate the applicability of the developed approach for the examination of MS patients.

Relaxation-weighted Na magnetic resonance imaging maps regional patterns of abnormal sodium concentrations in amyotrophic lateral sclerosis.

Objectives: Multiparametric magnetic resonance imaging (MRI) is established as a technical instrument for the characterisation of patients with amyotrophic lateral sclerosis (ALS). The contribution of relaxation-weighted sodium (NaR) MRI remains to be defined. The aim of this study is to apply NaR MRI to investigate brain sodium homeostasis and map potential alterations in patients with ALS as compared with healthy controls.

Motion-corrected Na MRI of the human brain using interleaved H 3D navigator images.

Purpose: To evaluate the feasibility of motion correction for sodium ( Na) MRI based on interleaved acquired 3D proton ( H) navigator images.

Methods: A 3D radial density-adapted sequence for interleaved Na/ H MRI was implemented on a 7 Tesla whole-body MRI system. The H data obtained during the Na acquisition were used to reconstruct 140 navigator image volumes with a nominal spatial resolution of (2.

Quantification of Sodium Relaxation Times and Concentrations as Surrogates of Proteoglycan Content of Patellar CARTILAGE at 3T MRI.

Sodium MRI has the potential to depict cartilage health accurately, but synovial fluid can influence the estimation of sodium parameters of cartilage. Therefore, this study aimed to reduce the impact of synovial fluid to render the quantitative compositional analyses of cartilage tissue technically more robust. Two dedicated protocols were applied for determining sodium T1 and T2* relaxation times.

Quantitative H and Na muscle MRI in Facioscapulohumeral muscular dystrophy patients.

Objective: Our aim was to assess the role of quantitative H and Na MRI methods in providing imaging biomarkers of disease activity and severity in patients with Facioscapulohumeral muscular dystrophy (FSHD).

Methods: We imaged the lower leg muscles of 19 FSHD patients and 12 controls with a multimodal MRI protocol to obtain STIR-Tw images, fat fraction (FF), water T (wT), water T (wT), tissue sodium concentration (TSC), and intracellular-weighted sodium signal (inversion recovery (IR) and triple quantum filter (TQF) sequence). In addition, the FSHD patients underwent muscle strength testing.

Towards accelerated quantitative sodium MRI at 7 T in the skeletal muscle: Comparison of anisotropic acquisition- and compressed sensing techniques.

Purpose: To compare three anisotropic acquisition schemes and three compressed sensing (CS) approaches for accelerated tissue sodium concentration (TSC) quantification using Na MRI at 7 T.

Materials And Methods: Three anisotropic 3D-radial acquisition sequences were evaluated using simulations, phantom- and in vivo TSC measurements: An anisotropic density-adapted 3D-radial sequence (3DPR-C), a 3D acquisition-weighted density-adapted stack-of-stars sampling scheme (SOS) and a SOS approach with golden-ratio rotation (SOS-GR). Eight healthy volunteers were examined at a 7 Tesla MRI system.

Combined imaging of potassium and sodium in human skeletal muscle tissue at 7 T.

Purpose: To validate the feasibility of quantitative combined potassium ( K) and sodium ( Na) MRI in human calf muscle tissue, as well as to evaluate the reproducibility of the apparent tissue potassium concentration (aTPC) and apparent tissue sodium concentration (aTSC) determination in healthy muscle tissue.

Methods: Quantitative Na and K MRI acquisition protocols were implemented on a 7 T MR system. A double-resonant Na/ K birdcage RF coil was used.

Assessing the variability of Na MRI in skeletal muscle tissue: Reproducibility and repeatability of tissue sodium concentration measurements in the lower leg at 3 T.

The goal of this study was to evaluate the reproducibility and repeatability of tissue sodium concentration (TSC) measurements using Na MRI in skeletal muscle tissue. Na MRI was performed at 3 T on the right lower leg of eight healthy volunteers (aged 28 ± 4 years). The examinations were repeated at the same site after ~ 22 weeks to assess the variability over a medium-term period.

Correction to: Accelerated quantification of tissue sodium concentration in skeletal muscle tissue: quantitative capability of dictionary learning compressed sensing.

The original version of this article unfortunately contained a mistake. Title was incorrect.

Accelerated quantification of tissue sodium concentration in skeletal muscle tissue: quantitative capability of dictionary learning compressed sensing.

Objective: To accelerate tissue sodium concentration (TSC) quantification of skeletal muscle using Na MRI and 3D dictionary-learning compressed sensing (3D-DLCS).

Materials And Methods: Simulations and in vivo Na MRI examinations of calf muscle were performed with a nominal spatial resolution of [Formula: see text]. Fully sampled and three undersampled Na MRI data sets (undersampling factors (USF) = 3, 4.

Localized B shimming based on Na MRI at 7 T.

Purpose: To validate the feasibility of localized B shimming based on B maps acquired with sodium ( Na) MRI.

Methods: A localized B shimming routine based on a constrained regularized algorithm in combination with Na MRI data acquired with a 3D density-adapted radial readout scheme was implemented on a 7T MR system. Measurements were performed using a dual-tuned Na/ H head coil.

Na MRI of human skeletal muscle using long inversion recovery pulses.

Na inversion recovery (IR) imaging allows for a weighting toward intracellular sodium in the human calf muscle and thus enables an improved analysis of pathophysiological changes of the muscular ion homeostasis. However, sodium signal-to-noise ratio (SNR) is low, especially when using IR sequences. Na has a nuclear spin of 3/2 and therefore experiences a strong electrical quadrupolar interaction.

Na MRI depicts early changes in ion homeostasis in skeletal muscle tissue of patients with duchenne muscular dystrophy.

Background: Duchenne muscular dystrophy (DMD) is a hereditary neuromuscular disease leading to progressive muscle wasting. Since there is a need for MRI variables that serve as early sensitive indicators of response to treatment, several quantitative MRI methods have been suggested for disease monitoring.

Purpose: To evaluate the potential of sodium ( Na) and proton ( H) MRI methods to assess early pathological changes in skeletal muscle of DMD.

Double quantum filtered Na MRI with magic angle excitation of human skeletal muscle in the presence of B and B inhomogeneities.

Double quantum filtered Na MRI with magic angle excitation (DQF-MA) can be used to selectively detect sodium ions located within anisotropic structures such as muscle fibers. It might therefore be a promising tool to analyze the microscopic environment of sodium ions, for example in the context of osmotically neutral sodium retention. However, DQF-MA imaging is challenging due to various signal dependences, on both measurement parameters and external influences.