Classification of liver lesions based on temporal changes in hepatobiliary phase contrast on magnetic resonance imaging: a preliminary study.

This study evaluated whether temporal changes from the dynamic late phase to the hepatobiliary phase using gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid supported liver tumor classification. A total of 147 patients with 165 lesions (hepatocellular carcinoma [HCC], metastases, and hemangiomas) underwent 3.0 T MRI.

Effect of posture on renal volume: evaluation using multi-posture MRI.

Measurement of renal volume is useful in the early detection and monitoring of renal disease. However, changes in renal volume during postural changes are not clear. Therefore, this study used multi-posture MRI system that can obtain renal images in any posture to assess the effect of posture on renal volume in the supine and upright positions.

Temporal changes in sucrose phantoms for magnetic resonance imaging: effects of preparation temperatures.

This study investigated the effects of preparation temperature and usage period on the relaxation times and apparent diffusion coefficients (ADC) of sucrose phantoms to enhance imaging reliability. Phantoms were prepared using 10% sucrose solutions at 20, 50, and 80 °C. T1 and T2 relaxation times and ADC were monitored over 80 days using magnetic resonance imaging on a 1.

Multicomponent T* Analysis of Atherosclerotic Plaque with Ultrashort Echo Time Imaging: A Phantom Study.

Purpose: To evaluate short T components potentially reflecting calcification or other susceptibility-affected tissue components in atherosclerotic plaques, using multicomponent analysis with ultrashort TE (UTE) MRI.

Methods: A phantom experiment was conducted using a 4-echo UTE sequence, mimicking the sample as a small amount of calcification found intra-voxel. The phantom included 6 samples containing varying concentrations of hydroxyapatite (calcification) and mayonnaise (lipid-water emulsion).

Optimization of three-dimensional T2-weighted image sequences in female pelvic magnetic resonance imaging.

This study aimed to characterize T2-weighted fast spin-echo three-dimensional (3D) magnetic resonance images (MRI) by using variable refocusing angle (VRFA) in female pelvic organs and to extract clinically relevant parameters. A 3T MRI system was used, and contrast-to-noise ratio (CNR) and full width at half maximum (FWHM) were calculated using a phantom mimicking the uterine three-layered structure to confirm the characteristics of low-constant VRFA (LC-VRFA) and tissue-specific VRFA (TS-VRFA) under changing parameters. Parameters that were relatively well-evaluated in the phantom study were combined and visually evaluated as an overall assessment by volunteer images, using common turbo spin-echo (TSE) coefficients and equivalent TE (TEequiv).

Effect of Body Position on Dynamic Apparent Diffusion Coefficient Changes During the Cardiac Cycle in the Human Brain.

Background: Dynamic changes in the apparent diffusion coefficient (ΔADC) during the cardiac cycle reflect water molecule fluctuations in the brain and intracranial conditions. While body position strongly affects intracranial conditions, the relationship between ΔADC and body position has been less explored, as conventional MRI is typically performed only in the supine position.

Purpose: To investigate ΔADC and mean ADC (ADC) of the brain in supine and sitting positions using a multi-posture MRI system.

Characterization of the evaluation method for hepatobiliary phase image by liver magnetic resonance imaging using Gd-EOB-DTPA.

Purpose: This study aimed to characterize quantitative liver-spleen contrast (Q-LSC) and hepatocellular uptake index (HUI) for evaluating hepatobiliary phase (HBP) images using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) in liver magnetic resonance imaging and to identify differences in the results obtain from these two measurement methods.

Methods: Twenty-nine consecutive randomly selected patients were assessed using the 3.0 T MR system.

Comparative analysis of synthetic and conventional magnetic resonance imaging features across various brain regions.

Purpose: This study compared the contrast characteristics of synthetic magnetic resonance imaging (MRI) with conventional MRI in normal brain tissue and tumor-related areas.

Methods: A retrospective analysis was performed on 60 patients who underwent noncontrast synthetic and conventional MRIs. Synthetic MRI was reconstructed to match conventional MRI parameters using magnetization-prepared 2 rapid acquisition gradient echoes and multiple spin echo sequences.

Evaluation of gravity effect on liver and spleen volumes using multiposture MRI.

Liver and spleen volume measurements are important for early detection and monitoring of liver disease. However, alterations in liver and spleen volumes with postural changes, i.e.

Can bile excretion on Gd-EOB-MRI be used as a visual criterion for the hepatobiliary phase?

To determine whether visually observed biliary excretion of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) can be used to assess contrast adequacy of hepatobiliary phase (HBP) images. Images of 121 patients undergoing Gd-EOB-DTPA-enhanced magnetic resonance imaging were used. Adequate HBP images were defined as a quantitative liver-spleen contrast ratio (Q-LSC) ≥ 1.

Pulsation artifact reduction using compressed sensitivity encoding in Gd-EOB-DTPA contrast-enhanced magnetic resonance imaging.

In Gd-EOB-DTPA-enhanced MRI, cardiac pulsation artifacts in the left lobe often hinder diagnosis, the image quality need to improve. This study aimed to reduce cardiac pulsation artifacts in Gd-EOB-DTPA-enhanced three-dimensional (3D) T1-weighted turbo-field echo (3D-T1TFE) using compressed sensitivity encoding (CS).For phantom evaluation, the cardiac phantom was manually operated using a metronome-synchronized apparatus, comprising a bag-valve mask, a breathing circuit, and a Jackson-Rees system.

Clinical evaluation of 3D high-resolution isotropic knee MRI using Multi-Interleaved X-prepared TSE with inTUitive RElaxometry (MIXTURE) for simultaneous morphology and T2 mapping.

Purpose: Quantitative MRI techniques such as T2 mapping are useful in comprehensive evaluation of various pathologies of the knee joint yet require separate scans to conventional morphological measurements and long acquisition times. The recently introduced 3D MIXTURE (Multi-Interleaved X-prepared Turbo-Spin Echo with Intuitive Relaxometry) technique can obtain simultaneous morphologic and quantitative information of the knee joint. To compare MIXTURE with conventional methods and to identify differences in morphological and quantitative information.

Can Three-Dimensional T1-weighted MR Imaging Visualize the Vascular Lumen after Carotid Artery Stenting?

Purpose: We aimed to evaluate the quality of various 3D T-weighted images (TWIs) of the stent lumen using a carotid stent phantom and determine the suitable TWI sequence for visualization of the stent lumen after carotid artery stenting.

Methods: The carotid stent phantom consisted of polypropylene tubes that mimicked common carotid arteries with and without stenting. On 1.

Gray-white matter contrast reversal on T-weighted spin-echo in postmortem brain.

Purpose: The image contrast of postmortem magnetic resonance imaging (MRI) may differ from that of antemortem MRI because of circulator arrest, changes in postmortem tissue, and low-body-temperature scanning conditions. In fact, we have found that the signal intensity of white matter (WM) on T1-weighted spin-echo (T1WSE) images of the postmortem brain was lower than that of gray matter (GM), which resulted in image contrast reversal between GM and WM relative to the living brain. However, the reason for this phenomenon is unclear.

Immediate effect of upright position on lumbar disc using multiposture MRI: Preliminary results.

Objectives: Gravity loading on lumbar intervertebral discs (IVDs) is affected by body position. Although the long-term effects of gravity on IVDs have been reported, the immediate effects of gravity on IVDs remain unclear. We considered that changes in IVD structure in the upright and supine positions provided new diagnostic information.

Simulation of time-intensity curve based on k-space filling in breast dynamic contrast-enhanced three-dimensional magnetic resonance imaging.

This study elucidated the effects of a three-dimensional k-space trajectory incorporating the partial Fourier (PF) technique on a time-intensity curve (TIC) in a dynamic contrast-enhanced magnetic resonance imaging of a typical malignant breast tumor using a digital phantom. Images were obtained from the Cancer Imaging Archive Open Data for Breast Cancer, and 1-min scans with high temporal resolution were analyzed. The order of the k-space trajectory was set as Linear (sequential), Low-High (centric), PF (62.

Usefulness of fat-containing agents: an initial study on estimating fat content for magnetic resonance imaging.

This initial study aimed at testing whether fat-containing agents can be used for the fat mass estimation methods using magnetic resonance imaging (MRI). As an example for clinical application, fat-containing agents (based on soybean oil, 10% and 20%), 100% soybean oil, and saline as reference substances were placed outside the proximal femurs obtained from 14 participants and analyzed by 0.3 T MRI.

Prediction of tissue deformation based on mechanical and physiological factors in the prone position during surgery.

Aim: This study aimed to predict tissue deformation based on the pressure applied while lying in the prone position and physiological factors.

Methods: Healthy volunteers were instructed to lie on mattresses of four different hardness levels (50, 87.5, 175, and 262.

Extrusion of the medial meniscus under a weight-loading condition in early knee osteoarthritis: an investigation using special upright magnetic resonance imaging.

Background: Whether the medial meniscus morphology and movement occur under upright loading conditions in early knee osteoarthritis (OA) or medial meniscus posterior root tear (MMPRT) remains unknown. This study aimed to evaluate the medial and anteroposterior extrusion of the medial meniscus under unloaded and upright-loaded conditions in patients with early knee OA.

Methods: Twelve patients with early knee OA and 18 healthy adult volunteers participated in this study.

Tri- and bi-exponential diffusion analyses of the kidney: effect of respiratory-controlled acquisition on diffusion parameters.

This study examined whether respiratory-controlled acquisition influences diffusion parameters obtained with intravoxel incoherent motion (IVIM) analysis using tri-exponential and bi-exponential models. Ten healthy volunteers were examined on a 3.0 T MRI system to obtain coronal diffusion-weighted images of both kidneys.

Validating scapular motion measurements using an optical motion analyzer and gravity magnetic resonance imaging.

[Purpose] This study aimed to validate whether scapular motion measured using a pad with retroreflective markers and optical motion analyzer (VICON MX) can reflect the motion calculated by images using multi-posture (gravity) magnetic resonance imaging. [Participants and Methods] The participants were 12 healthy males (12 dominant-side shoulders). The measurement items were the scapular angle at shoulder flexion 140° and 160° and abduction 100°, 120°, 140°, and 160°.

Dependence of apparent diffusion coefficient on slice position in magnetic resonance diffusion imaging.

Purpose: The position dependence of the apparent diffusion coefficient (ADC) in magnetic resonance imaging (MRI) by echo-planar imaging (EPI)- and turbo spin echo (TSE)-diffusion-weighted imaging (DWI) was assessed using phantoms.

Methods: Six pure water-filled containers were placed parallel to the direction of the static magnetic field from the center of the magnetic field to the foot direction (five containers) and the head direction (one container). Six slice positions were set, and a cross-section image was scanned at the center of each container using a 1.

Temperature measurement of intracranial cerebrospinal fluid using diffusion tensor imaging after revascularization surgery in Moyamoya disease.

Objective: Brain temperature monitoring using a catheter thermometer has been reported to be a useful technique to predict prognosis in neurosurgery. To investigate the possibility of measuring intracranial cerebrospinal fluid temperature for postoperative monitoring in patients with Moyamoya disease (MMD) after bypass surgery.

Materials And Methods: This study evaluated fifteen patients with MMD who were indicated for bypass surgery.