Usefulness of T2 star-weighted imaging in ovarian cysts and tumors.

Aim: The aim of this study was to investigate the prevalence of hypointensity on T2 star-weighted imaging (T2*WI), which is useful for detecting hemosiderin, in endometriomas and other ovarian tumors. The efficacy of detecting adhesions around ovarian tumors was also investigated.

Methods: Pelvic magnetic resonance (MR) examinations, including T2*WI, were carried out.

Relationship between MRI T1 rho value and histological findings of intact and radially incised menisci in microminipigs.

Purpose: To examine whether the T1 rho value reflects histological changes in menisci we analyzed the relationship between T1 rho value and histological findings in intact and radially incised menisci of pigs.

Materials And Methods: Seven microminipigs were used for this experiment. A radial incision was created and repaired in the medial meniscus, which was evaluated 4 weeks after surgery.

The superior ophthalmic vein: delineation with high-resolution magnetic resonance imaging.

Objective: To delineate the superior ophthalmic vein (SOV) with high-resolution magnetic resonance (MR) imaging.

Methods: This retrospective study enrolled 302 consecutive outpatients, 101 patients, 51 males and 50 females, who underwent coronal T2-weighted imaging and 201 patients, 99 males and 102 females, who underwent three-dimensional (3D) phase-contrast (PC) MR angiography.

Results: Coronal T2-weighted imaging clearly delineated the intraorbital course of SOV on serial images in all 101 subjects.

Improvement of T1 contrast in whole-brain black-blood imaging using motion-sensitized driven-equilibrium prepared 3D turbo spin echo (3D MSDE-TSE).

We demonstrated a new scheme for performing the T1-enhanced whole-brain black-blood imaging pulse sequence using motion-sensitized driven-equilibrium prepared 3-dimensional (3D) turbo spin echo (MSDE-TSE) with anti-driven-equilibrium post pulse. The use of an anti-driven-equilibrium pulse considerably improved the T1 contrast of MSDE-TSE black-blood images. This sequence can be used for whole-brain 3D volumetric T1-weighted black-blood imaging and may improve the accuracy of anatomical localization for certain brain lesions.

Rapid high resolution MR neurography with a diffusion-weighted pre-pulse.

Purpose: To introduce, optimize, and assess the feasibility of a new scheme to rapidly acquire high-resolution volumetric neurographic images using a three-dimensional turbo spin-echo sequence combined with a diffusion-weighted pre-pulse called improved motion-sensitized driven equilibrium (iMSDE): Diffusion-prepared MR Neurography (D-prep MRN).

Methods: In order to optimize the signal suppression of blood vessels and muscle at D-prep MRN, coronal lumbosacral plexus images were acquired in five volunteers at 3T, and the following parameters were examined: iMSDE gradient-strength (b-value) of 0, 2 and 10 s/mm² (with the aim to suppress blood vessels) and iMSDE preparation duration (iMSDEprep-time) of 18, 50 and 100 ms (with the aim to suppress muscle signal). Subsequently, the feasibility of the optimized D-prep MRN sequence in visualizing the brachial plexus, lumbosacral plexus, and cranial nerves was evaluated in 5 healthy volunteers.

Whole-brain black-blood imaging with magnetization-transfer prepared spin echo-like contrast: a novel sequence for contrast-enhanced brain metastasis screening at 3T.

In contrast-enhanced (CE) brain metastasis screening, coexistence of enhanced blood vessel suppression and higher tumor-to-parenchyma contrast may improve radiologists' performances in detecting brain metastases compared with conventional sequences. In this study, we propose a new scheme, allowing both suppression of blood signals and improvement of tumor-to-parenchyma contrast, using motion-sensitized driven equilibrium prepared 3D low-refocusing flip-angle turbo spin echo (TSE) ("magnetization transfer prepared spin echo"-like contrast volume examination: MATLVE) for brain metastasis screening at 3.0 T, and we compare MATLVE to conventional three-dimensional (3D)-gradient recalled echo (GRE) and 3D-TSE sequences.

Calvarial diploic venous channels: an anatomic study using high-resolution magnetic resonance imaging.

Background: The calvarial diploic venous channels (CDVCs) are well-known intraosseous structures, but their distribution and anatomofunctional implications are not fully understood.

Objective: To investigate the architecture of CDVCs using high-resolution magnetic resonance (MR) imaging.

Method: This prospective study enrolled 43 male and 37 female outpatients who underwent a 3.

Vessel-selective, non-contrast enhanced, time-resolved MR angiography with vessel-selective arterial spin labeling technique (CINEMA-SELECT) in intracranial arteries.

We demonstrate the feasibility of the vessel-selective, non-contrast, time-resolved magnetic resonance angiography (MRA) technique, "contrast inherent inflow enhanced multi-phase angiography combining vessel-selective arterial spin labeling technique (CINEMA-SELECT)". This sequence consists of two major techniques: pulsed star labeling of arterial regions (PULSAR) and Look-Locker sampling. We hypothesize that this technique allows selective labeling of single intracranial arteries, consisting of high-resolution four-dimensional data with a wide coverage of the brain.

Reevaluation of T2-weighted fast field echo (T2FFE): application to rapid volumetric black-blood imaging.

T₂-fast field echo (T2FFE) sequence is a rapid T₂-weighted steady state free precession sequence, but has not become a widely utilized MR-imaging strategy because of its low signal-to-noise ratio and high sensitivity to motion. These effects have seriously limited the clinical use of T2FFE and therefore T2FFE has not been used for routine clinical studies. Nevertheless, in this study, we have investigated the possibility of clinical application by re-optimization of the T2FFE on the current MRI systems.

[Non-contrast time-resolved magnetic resonance angiography combining high resolution multiple phase echo planar imaging based signal targeting and alternating radiofrequency contrast inherent inflow enhanced multi phase angiography combining spatial resolution echo planar imaging based signal targeting and alternating radiofrequency in intracranial arteries].

Detailed information on anatomy and hemodynamics in cerebrovascular disorders such as AVM and Moyamoya disease is mandatory for defined diagnosis and treatment planning. Arterial spin labeling technique has come to be applied to magnetic resonance angiography (MRA) and perfusion imaging in recent years. However, those non-contrast techniques are mostly limited to single frame images.

Venous lacunae presenting with unusual upward protrusion: an anatomic study using high-resolution magnetic resonance imaging.

Purpose: This study aims to investigate the distribution and anatomic features of venous lacuna presenting with unusual upward protrusion (VLUUP) using high-resolution magnetic resonance (MR) imaging.

Methods: This retrospective study included 59 consecutive outpatients who underwent MR imaging with gadolinium. Acquired imaging data were transferred to a workstation for analysis.

An anatomic study of the inferior oblique nerve with high-resolution magnetic resonance imaging.

Objective: To investigate anatomic features of the inferior oblique nerve (IObN) by high-resolution magnetic resonance (MR) imaging and cadaveric dissection.

Methods: This study enrolled 100 consecutive outpatients, who underwent 3.0 T MR imaging equipped by the 32-channel head coil.

Optimization of 3D-variable refocusing flip angle RARE imaging for high-resolution volumetric black-blood angiography.

3D rapid acquisition with relaxation enhancement or turbo spin-echo sequence is promising for black-blood angiography. In this paper, we propose a new scheme of sequence parameter optimization for "flow-void enhanced" volumetric black-blood angiography. Although black-blood imaging has numerous applications, we focused on the carotid artery in this study.

Visualization of the ophthalmic artery by phase-contrast magnetic resonance angiography: a pilot study.

Objective: This study aimed at investigating whether phase-contrast (PC) magnetic resonance (MR) angiography is useful for visualizing the ophthalmic artery (OA).

Methods: This prospective study enrolled 196 consecutive outpatients who underwent three-dimensional PC MR angiography. The basal image parallel to the anteroposterior dimension of the OA was extracted for analysis from the imaging data.

The Virchow-Robin spaces: delineation by magnetic resonance imaging with considerations on anatomofunctional implications.

Introduction: The Virchow-Robin spaces (V-R spaces) are well-known, but not systematically understood fluid-filled perivascular spaces that allow the convexity and basal perforating vessels to penetrate deep into the cerebral parenchyma.

Objective: This study aims to delineate anatomical characteristics of the normal V-R spaces by MR imaging with considerations on clinical and anatomofunctional implications of the V-R spaces.

Methods: In this prospective study with 3T magnetic resonance (MR) imaging, the whole extent of the intracranial V-R spaces was classified into basal, cortical, subcortical, paraventricular, and brainstem segments, on the basis of the topological difference in 105 control subjects.

Intradiscal transplantation of synovial mesenchymal stem cells prevents intervertebral disc degeneration through suppression of matrix metalloproteinase-related genes in nucleus pulposus cells in rabbits.

Introduction: Synovial mesenchymal stem cells (MSCs) have high proliferative and chondrogenic potentials, and MSCs transplanted into the articular cartilage defect produce abundant extracellular matrix. Because of similarities between the articular cartilage and the intervertebral disc cartilage, synovial MSCs are a potential cell source for disc regeneration. Here, we examined the effect of intradiscal transplantation of synovial MSCs after aspiration of nucleus pulposus in rabbits.

Quantification of left ventricular volumes from cardiac cine MRI using active contour model combined with gradient vector flow.

We investigated the feasibility of combining the active contour model with gradient vector flow (Snakes-GVF) to estimate left ventricular (LV) volumes from cardiac cine magnetic resonance imaging (MRI). MRI data were acquired from 27 patients, including 14 adults (9 men, 5 women, 55.0+/-23.

Automatic motion correction for quantification of myocardial perfusion with dynamic magnetic resonance imaging.

Respiratory motion makes it difficult to quantify myocardial perfusion with dynamic magnetic resonance imaging (MRI). The purpose of this study was to evaluate an automatic registration method for motion correction for quantification of myocardial perfusion with dynamic MRI. The present method was based on the gradient-based method with robust estimation of displacement parameters.