MRI denoising with a non-blind deep complex-valued convolutional neural network.

MR images with high signal-to-noise ratio (SNR) provide more diagnostic information. Various methods for MRI denoising have been developed, but the majority of them operate on the magnitude image and neglect the phase information. Therefore, the goal of this work is to design and implement a complex-valued convolutional neural network (CNN) for MRI denoising.

A comparative cadaveric biomechanical study of bilateral FacetFuse transfacet pedicle screws versus bilateral or unilateral pedicle screw-rod construct.

Background: Achieving optimal immediate stability is crucial in lumbar fusion surgeries. Traditionally, four pedicle screws have been utilized to provide posterior stability at the L5-S1 level. However, the use of bilateral transfacet pedicle screws (TFPS) as an alternative construct has shown promising results in terms of biomechanical stability.

Prospective Trial of Sacroiliac Joint Fusion Using 3D-Printed Triangular Titanium Implants: 5-Year Follow-Up.

Study Design: Prospective, multicenter, single arm study with 5-year follow up.

Objective: To report long-term (5-year) safety, effectiveness, and radiographic outcomes after sacroiliac (SI) joint fusion (SIJF) with 3D-printed triangular titanium implants (TTI) and compare them with solid titanium plasma spray coated implants.

Summary Of Background Data: A large literature base supports minimally invasive SIJF with TTI for chronic SIJ dysfunction.

Associations between the choroid plexus and tau in Alzheimer's disease using an active learning segmentation pipeline.

Background: The cerebrospinal fluid (CSF), primarily generated by the choroid plexus (ChP), is the major carrier of the glymphatic system. The alternations of CSF production and the ChP can be associated with the Alzheimer's disease (AD). The present work investigated the roles of the ChP in the AD based on a proposed ChP image segmentation pipeline.

Clinical and economic outcomes associated with lymph node examination status in early-stage non-small cell lung cancer: a real-world US study using the SEER-Medicare linked database.

Background: Clinical practice guidelines recommend adjuvant therapy for patients with early non-small cell lung cancer (eNSCLC), especially those with lymph node metastasis. This study evaluated the prevalence of lymph node examination and its association with adjuvant treatment rates, overall survival (OS), and healthcare costs among United States (US) Medicare patients with resected eNSCLC.

Methods: This retrospective observational cohort study used Surveillance, Epidemiology, and End Results cancer registry data linked with Medicare claims data.

Hyperpolarized Xe MRI, Tc scintigraphy, and SPECT in lung ventilation imaging: a quantitative comparison.

Rationale And Objectives: The current clinical standard for functional imaging of patients with lung ailments is nuclear medicine scintigraphy and Single Photon Emission Computed Tomography (SPECT) which detect the gamma decay of inhaled radioactive tracers. Hyperpolarized (HP) Xenon-129 MRI (XeMRI) of the lungs has recently been FDA approved and provides similar functional images of the lungs with higher spatial resolution than scintigraphy and SPECT. Here we compare Technetium-99m (Tc) diethylene-triamine-pentaacetate scintigraphy and SPECT with HP XeMRI in healthy controls, asthma, and chronic obstructive pulmonary disorder (COPD) patients.

Probability of Cavitation in a Custom Iron-Based Coupling Medium for Transcranial Magnetic Resonance-Guided Focused Ultrasound Procedures.

Objective: A coupling bath of circulating, chilled, degassed water is essential to safe and precise acoustic transmittance during transcranial magnetic resonance-guided focused ultrasound (tMRgFUS) procedures, but the circulating water impairs the critical real-time magnetic resonance imaging (MRI). An iron-based coupling medium (IBCM) using iron oxide nanoparticles previously developed by our group increased the relaxivity of the coupling bath such that it appears to be invisible on MRI compared with degassed water. However, the nanoparticles also reduced the pressure threshold for cavitation.

Dynamic cardiac MRI with high spatiotemporal resolution using accelerated spiral-out and spiral-in/out bSSFP pulse sequences at 1.5 T.

Objective: To develop two spiral-based bSSFP pulse sequences combined with L + S reconstruction for accelerated ungated, free-breathing dynamic cardiac imaging at 1.5 T.

Materials And Methods: Tiny golden angle rotated spiral-out and spiral-in/out bSSFP sequences combined with view-sharing (VS), compressed sensing (CS), and low-rank plus sparse (L + S) reconstruction were evaluated and compared via simulation and in vivo dynamic cardiac imaging studies.

Dark band artifact in transcranial MR-guided focused ultrasound: Mechanism and mitigation with passive crossed wire antennas.

Current FDA-approved transcranial MR-guided focused ultrasound (tcMRgFUS) transducers cause a curved dark band in 3 T brain images that runs through midbrain targets of ablative treatments for essential tremor and other applications, and signal is reduced by at least 25% elsewhere in the brain. This limits the set of scans that can be performed to guide and assess the effects of treatment. An electromagnetic simulation study was performed to elucidate the mechanisms causing the dark band.

Improving biomarker testing in advanced non-small-cell lung cancer and metastatic colorectal cancer: experience from a large community oncology network in the USA.

Biomarker testing detects actionable driver mutations to inform first-line treatment in advanced non-small-cell lung cancer (aNSCLC) and metastatic colorectal cancer (mCRC). This study evaluated biomarker testing in a nationwide database (NAT) versus the OneOncology (OneOnc) community network. Patients with aNSCLC or mCRC with ≥1 biomarker test in a de-identified electronic health record-derived database were evaluated.

Concomitant field compensation of spiral turbo spin-echo at 0.55 T.

Objective: Diagnostic-quality neuroimaging methods are vital for widespread clinical adoption of low field MRI. Spiral imaging is an efficient acquisition method that can mitigate the reduced signal-to-noise ratio at lower field strengths. As concomitant field artifacts are worse at lower field, we propose a generalizable quadratic gradient-field nulling as an echo-to-echo compensation and apply it to spiral TSE at 0.

Athlete Muscular Phenotypes Identified and Compared with High-Dimensional Clustering of Lower Limb Muscle Volume Measurements.

Introduction: Athletes use their skeletal muscles to demonstrate performance. Muscle force generating capacity is correlated with volume, meaning that variations in sizes of different muscles may be indicative of how athletes meet different demands in their sports. Medical imaging enables in vivo quantification of muscle volumes; however, muscle volume distribution has not been compared across athletes of different sports.

Alirocumab and plaque volume, calf muscle blood flow, and walking performance in peripheral artery disease: A randomized clinical trial.

Background: The distal superficial femoral artery (SFA) is most commonly affected in peripheral artery disease (PAD). The effects of the proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor alirocumab added to statin therapy on SFA atherosclerosis, downstream flow, and walking performance are unknown.

Methods: Thirty-five patients with PAD on maximally tolerated statin therapy were recruited.

Concomitant magnetic-field compensation for 2D spiral-ring turbo spin-echo imaging at 0.55T and 1.5T.

Purpose: To develop 2D turbo spin-echo (TSE) imaging using annular spiral rings (abbreviated "SPRING-RIO TSE") with compensation of concomitant gradient fields and B inhomogeneity at both 0.55T and 1.5T for fast T -weighted imaging.

Rapid whole-brain quantitative MT imaging.

Purpose: To provide a robust whole-brain quantitative magnetization transfer (MT) imaging method that is not limited by long acquisition times.

Methods: Two variants of a spiral 2D interleaved multi-slice spoiled gradient echo (SPGR) sequence are used for rapid quantitative MT imaging of the brain at 3 T. A dual flip angle, steady-state prepared, double-contrast method is used for combined B and-T mapping in combination with a single-contrast MT-prepared acquisition over a range of different saturation flip angles (50 deg to 850 deg) and offset frequencies (1 kHz and 10 kHz).

QU-BraTS: MICCAI BraTS 2020 Challenge on Quantifying Uncertainty in Brain Tumor Segmentation - Analysis of Ranking Scores and Benchmarking Results.

Deep learning (DL) models have provided state-of-the-art performance in various medical imaging benchmarking challenges, including the Brain Tumor Segmentation (BraTS) challenges. However, the task of focal pathology multi-compartment segmentation (e.g.

Highly accelerated dynamic acquisition of 3D grid-tagged hyperpolarized-gas lung images using compressed sensing.

Purpose: To develop and test compressed sensing-based multiframe 3D MRI of grid-tagged hyperpolarized gas in the lung.

Theory And Methods: Applying grid-tagging RF pulses to inhaled hyperpolarized gas results in images in which signal intensity is predictably and sparsely distributed. In the present work, this phenomenon was used to produce a sampling pattern in which k-space is undersampled by a factor of approximately seven, yet regions of high k-space energy remain densely sampled.

Patients with allergic asthma have lower risk of severe COVID-19 outcomes than patients with nonallergic asthma.

Background: Although asthma does not appear to be a risk factor for severe coronavirus disease 2019 (COVID-19), outcomes could vary for patients with different asthma subtypes. The objective of this analysis was to compare COVID-19 outcomes in real-world cohorts in the United States among patients with asthma, with or without evidence of allergy.

Methods: In a retrospective analysis of the COVID-19 Optum electronic health record dataset (February 20, 2020-January 28, 2021), patients diagnosed with COVID-19 with a history of moderate-to-severe asthma were divided into 2 cohorts: those with evidence of allergic asthma and those without (nonallergic asthma).

Iron-based coupling media for MRI-guided ultrasound surgery.

Purpose: In this study, we examine the effects of a recently developed, iron-based coupling medium (IBCM) on guidance magnetic resonance (MR) scans during transcranial, magnetic-resonance-guided, focused ultrasound surgery (tMRgFUS) procedures. More specifically, this study tests the hypotheses that the use of the IBCM will (a) not adversely affect image quality, (b) remove aliasing from small field-of-view scans, and (c) decouple image quality from the motion state of the coupling fluid.

Methods: An IBCM, whose chemical synthesis and characterization are reported elsewhere, was used as a coupling medium during tMRgFUS procedures on gel phantoms.

Durability of Protection Post-Primary COVID-19 Vaccination in the United States.

The durability of immune responses after COVID-19 vaccination will drive long-term vaccine effectiveness across settings and may differ by vaccine type. To determine durability of protection of COVID-19 vaccines (BNT162b2, mRNA-1273, and Ad26.COV2.

Comparison between MR and CT imaging used to correct for skull-induced phase aberrations during transcranial focused ultrasound.

Transcranial focused ultrasound with the InSightec Exablate system uses thermal ablation for the treatment of movement and mood disorders and blood brain barrier disruption for tumor therapy. The system uses computed tomography (CT) images to calculate phase corrections that account for aberrations caused by the human skull. This work investigates whether magnetic resonance (MR) images can be used as an alternative to CT images to calculate phase corrections.

Chemical Exchange Saturation Transfer Magnetic Resonance Imaging Identifies Abnormal Calf Muscle-Specific Energetics in Peripheral Artery Disease.

Background: Peripheral artery disease (PAD) results in exercise-induced ischemia in leg muscles. Phosphorus (P) magnetic resonance spectroscopy demonstrates prolonged phosphocreatine recovery time constant after exercise in PAD but has low signal to noise, low spatial resolution, and requires multinuclear hardware. Chemical exchange saturation transfer (CEST) is a quantitative magnetic resonance imaging method for imaging substrate (CEST asymmetry [CEST]) concentration by muscle group.