Ferumoxytol-Enhanced Cardiac Cine MRI Reconstruction Using a Variable-Splitting Spatiotemporal Network.

Background: Balanced steady-state free precession (bSSFP) imaging is commonly used in cardiac cine MRI but prone to image artifacts. Ferumoxytol-enhanced (FE) gradient echo (GRE) has been proposed as an alternative. Utilizing the abundance of bSSFP images to develop a computationally efficient network that is applicable to FE GRE cine would benefit future network development.

Free-breathing 3D stack-of-radial MRI quantification of liver fat and R* in adults with fatty liver disease.

Purpose: To investigate the agreement, intra-session repeatability, and inter-reader agreement of liver proton-density fat fraction (PDFF) and R* quantification using free-breathing 3D stack-of-radial MRI, with and without self-gated motion compensation, compared to reference breath-hold techniques in subjects with fatty liver disease (FLD).

Methods: In this institutional review board-approved prospective study, thirty-eight adults with FLD and/or iron overload (24 male, 58 ± 12 years) were imaged at 3T using free-breathing stack-of-radial MRI, breath-hold 3D Cartesian MRI, and breath-hold single-voxel MR spectroscopy (SVS). Each sequence was acquired twice in random order.

Accelerated k-space shift calibration for free-breathing stack-of-radial MRI quantification of liver fat and .

Purpose: To develop an accelerated k-space shift calibration method for free-breathing 3D stack-of-radial MRI quantification of liver proton-density fat fraction (PDFF) and .

Methods: Accelerated k-space shift calibration was developed to partially skip acquisition of k-space shift data in the through-plane direction then interpolate in processing, as well as to reduce the in-plane averages. A multi-echo stack-of-radial sequence with the baseline calibration was evaluated on a phantom versus vendor-provided reference-standard PDFF and values at 1.

Free-Breathing Volumetric Liver and Proton Density Fat Fraction Quantification in Pediatric Patients Using Stack-of-Radial MRI With Self-Gating Motion Compensation.

Background: Stack-of-radial multiecho gradient-echo MRI is promising for free-breathing liver quantification and may benefit children.

Purpose: To validate stack-of-radial MRI with self-gating motion compensation in phantoms, and to evaluate it in children.

Study Type: Prospective.

Effect of respiratory motion on free-breathing 3D stack-of-radial liver relaxometry and improved quantification accuracy using self-gating.

Purpose: To develop an accurate free-breathing 3D liver mapping approach and to evaluate it in vivo.

Methods: A free-breathing multi-echo stack-of-radial sequence was applied in 5 normal subjects and 6 patients at 3 Tesla. Respiratory motion compensation was implemented using the inherent self-gating signal.

Improved accuracy of apparent diffusion coefficient quantification using a fully automatic noise bias compensation method: Preliminary evaluation in prostate diffusion weighted imaging.

Noise in diffusion magnetic resonance imaging can introduce bias in apparent diffusion coefficient (ADC) quantification. Previous studies proposed methods that are site-specific techniques as research tools with limited availability and typically require manual intervention, not completely ready to use in the clinical environment. The purpose of this study was to develop a fully automatic computational method to correct noise bias in ADC quantification and perform a preliminary evaluation in the clinical prostate diffusion weighted imaging (DWI).

Accurate fatty acid composition estimation of adipose tissue in the abdomen based on bipolar multi-echo MRI.

Purpose: To develop a bipolar multi-echo MRI method for the accurate estimation of the adipose tissue fatty acid composition (FAC) using clinically relevant protocols at clinical field strength.

Methods: The proposed technique jointly estimates confounding factors (field map, , eddy-current phase) and triglyceride saturation state parameters by fitting multi-echo gradient echo acquisitions to a complex signal model. The noise propagation behavior was improved by applying a low-rank enforcing denoising technique and by addressing eddy-current-induced phase discrepancies analytically.

Multiple focal nodular hyperplasia: MRI features.

Purpose: To describe MRI features of multiple Focal Nodular Hyperplasia (FNHs).

Methods: 40 consecutive subjects (37 females, mean age, 38.8years) were included.

Comparison of Cartesian and radial acquisition on short-tau inversion recovery (STIR) sequences in breast MRI.

Objective: The purpose of this study was to compare two short-tau inversion recovery (STIR) sequences, Cartesian and radial (BLADE) acquisitions, for breast magnetic resonance imaging (MRI) examinations.

Materials And Methods: Ninety-six women underwent 1.5 T breast MRI exam (48 Cartesian and 48 BLADE).

Effect of a Low-Rank Denoising Algorithm on Quantitative Magnetic Resonance Imaging-Based Measures of Liver Fat and Iron.

Purpose: This study aimed to assess the effect of a low-rank denoising algorithm on quantitative magnetic resonance imaging-based measures of liver fat and iron.

Materials And Methods: This was an institutional review board-approved, Health Insurance Portability and Accountability Act-compliant, retrospective analysis of 42 consecutive subjects who were imaged at 3T using a multiecho gradient echo sequence that was reconstructed using the multistep adaptive fitting algorithm to obtain quantitative proton density fat fraction (PDFF) and R2* maps (original maps). A patch-wise low-rank denoising algorithm was then applied, and PDFF and R2* maps were created (denoised maps).

Four-dimensional diffusion-weighted MR imaging (4D-DWI): a feasibility study.

Purpose: Diffusion-weighted Magnetic Resonance Imaging (DWI) has been shown to be a powerful tool for cancer detection with high tumor-to-tissue contrast. This study aims to investigate the feasibility of developing a four-dimensional DWI technique (4D-DWI) for imaging respiratory motion for radiation therapy applications.

Materials/methods: Image acquisition was performed by repeatedly imaging a volume of interest (VOI) using an interleaved multislice single-shot echo-planar imaging (EPI) 2D-DWI sequence in the axial plane.

Stability of liver proton density fat fraction and changes in R 2* measurements induced by administering gadoxetic acid at 3T MRI.

Objective: To assess changes in liver proton density fat fraction (PDFF) and R 2* measurements in the presence of changes in tissue relaxation rates induced by administrating gadoxetic acid, using two different image reconstruction methods at 3T MRI.

Methods: Forty-five patients were imaged at 3T with chemical-shift-based MRI sequences before and 20 min after administration of gadoxetic acid. Image reconstructions were performed using hybrid and complex methods to obtain PDFF and R 2* images.

Initial Experience of Applying TWIST-Dixon With Flexible View Sharing in Breast DCE-MRI.

Introduction: We developed a new fast imaging technique with flexible time-resolved angiography with stochastic trajectories (TWIST) view sharing to achieve variable temporal resolution and with flexible echo time Dixon to achieve robust fat suppression and to evaluate its application in breast dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI).

Materials And Methods: The TWIST-Dixon technique was improved with more flexible view sharing and echo times (TWIST-Dixon-Flex). In a dynamic series, each measurement can be separately prescribed as "full," "partial," or "center-only.

Surrogate arterial phase imaging using a long duration (≈1.5 min) radial acquisition T1-weighted sequence: an alternative in patients unable to breath-hold.

Background: Pediatric and adult patients unable to suspend respiration generally undergo magnetic resonance (MR) examinations that lack arterial phase imaging, which is a phase that provides substantial information on disease processes. An MR strategy that provides this type of information may be of considerable value.

Purpose: To describe and assess the feasibility and enhancement quality of early-phase imaging utilizing long-duration radial 3D-GRE imaging by initiating the sequence prior to starting contrast injection.

High Signal Intensity in Globus Pallidus and Dentate Nucleus on Unenhanced T1-weighted MR Images: Evaluation of Two Linear Gadolinium-based Contrast Agents.

Purpose: To determine if a correlation exists between the number of previous enhanced magnetic resonance (MR) imaging examinations and high signal intensity in the globus pallidus (GP) and dentate nucleus (DN) in patients who received gadodiamide (Omniscan), a linear nonionic gadolinium-based contrast agent, and in those who received gadobenate dimeglumine (MultiHance), a linear ionic contrast agent.

Materials And Methods: Institutional review board approval was obtained for this single-center retrospective study, with waiver of informed consent. The study population included 69 patients divided into two groups: Group 1 included patients who underwent gadodiamide-enhanced MR imaging, and group 2 included patients who underwent gadobenate dimeglumine-enhanced MR imaging.

MR-PET co-registration in upper abdominal imaging: quantitative comparison of two different T1-weighted gradient echo sequences: initial observations.

Purpose: The purpose of this study is to quantitatively compare the accuracy of spatial registration of Cartesian breath-hold 3D-GRE and non-respiratory-triggered free-breathing radial 3D-GRE images with PET data acquisition on whole-body hybrid MR-PET system.

Materials And Methods: Eight patients (six men and two women; mean age, 56.6 ± 5.

Advanced magnetic resonance techniques: 3 T.

Magnetic resonance (MR) imaging at 3 T is clinically feasible and, in the right context, can provide improvements compared with 1.5-T MR imaging. Improvements in both signal/noise ratio and contrast/noise ratio can be used to improve image homogeneity and/or spatial and temporal resolution.

In vivo sodium MR imaging of the abdomen at 3T.

Purpose: Transmembrane sodium ((23)Na) gradient is critical for cell survival and viability and a target for the development of anti-cancer drugs and treatment as it serves as a signal transducer. The ability to integrate abdominal (23)Na MRI in clinical settings would be useful to non-invasively detect and diagnose a number of diseases in various organ systems. Our goal in this work was to enhance the quality of (23)Na MRI of the abdomen using a 3-Tesla MR scanner and a novel 8-channel phased-array dual-tuned (23)Na and (1)H transmit (Tx)/receive (Rx) coil specially designed to image a large abdomen region with relatively high SNR.

Interexamination repeatability and spatial heterogeneity of liver iron and fat quantification using MRI-based multistep adaptive fitting algorithm.

Purpose: To assess the interexamination repeatability and spatial heterogeneity of liver iron and fat measurements using a magnetic resonance imaging (MRI)-based multistep adaptive fitting algorithm.

Materials And Methods: This prospective observational study was Institutional Review Board-approved and Health Insurance Portability and Accountability Act-compliant. Written informed consent was waived.

High-resolution 3D-GRE imaging of the abdomen using controlled aliasing acceleration technique - a feasibility study.

Objectives: To assess the feasibility of high-resolution 3D-gradient-recalled echo (GRE) fat-suppressed T1-weighted images using controlled aliasing acceleration technique (CAIPIRINHA-VIBE), and compare image quality and lesion detection to standard-resolution 3D-GRE images using conventional acceleration technique (GRAPPA-VIBE).

Materials And Methods: Eighty-four patients (41 males, 43 females; age range: 14-90 years, 58.8 ± 15.

MR-PET evaluation of 1-month post-ablation therapy for hepatocellular carcinoma: preliminary observations.

Purpose: The purpose of the study was to evaluate the feasibility and protocol optimization of whole-body hybrid MR-PET system performed 1-month after post-locoregional thermoablative procedures for hepatocellular carcinomas (HCCs).

Materials And Methods: Eight patients (6 men and 2 women; mean age, 56.6 ± 5.