Optimal Imaging Parameters for Readout-segmented EPI of the Temporal Bone.

Readout-segmented echo planar imaging (rs-EPI) is a form of multi-shot EPI. rs-EPI is affected less by susceptibility artifacts than single-shot EPI (ss-EPI), which is widely used for diffusion-weighted imaging, so rs-EPI is expected to produce less image distortion. In this study, we compared rs-EPI and conventional ss-EPI of the temporal bone region, which contains abundant amounts of air and frequently exhibits changes in magnetic susceptibility.

The agreement of left ventricular function parameters between (99m)Tc-tetrofosmin gated myocardial SPECT and gated myocardial MRI.

Objective: The aim is to compare and evaluate the agreement of quantification of left ventricular functional parameters obtained by two different methods, (99m)Tc-tetrofosmin gated myocardial perfusion SPECT (MPS) and cardiac magnetic resonance imaging (CMR).

Methods: Ten healthy male volunteers participated. Gated MPS data were acquired using 32 frames, which were also combined into 16- and 8-frame data set for the investigation.

MR signal change in venous thrombus relates organizing process and thrombolytic response in rabbit.

Venous thrombus is subsequently organized and replaced by fibrous connective tissue. However, the sequential changes in venous thrombi are not reliably detected by current noninvasive diagnostic techniques. The purpose of this study is to reveal whether magnetic resonance (MR) can detect venous thrombus, define thrombus age and predict thrombolytic responses.

Improved visualization of intracranial vessels by gradient moment nulling in hybrid of opposite-contrast magnetic resonance angiography (HOP MRA).

Hybrid of opposite-contrast (HOP) magnetic resonance angiography (MRA) is a new method that combines the advantages of 3-dimensional (3D) time-of-flight (TOF) MRA and black-blood (BB) MRA without prolonging acquisition time. In phantom and clinical studies, we focused on image differences when we applied gradient moment nulling (GMN) to 2 or 3 axes in the first echo. We made an original phantom with a semicircular tube of 3- and 5-mm internal diameter, with flow rate in the tube of 0, 20, 60, 80, or 120 cm/s.

Atherosclerotic lesions rich in macrophages or smooth muscle cells discriminated in rabbit iliac arteries based on T1 relaxation time and lipid content.

Rationale And Objectives: Atherothrombosis usually occurs on macrophage- and lipid-rich unstable plaque, but rarely on smooth muscle cell (SMC)-rich stable plaque. Magnetic resonance imaging (MRI) has been extensively applied for noninvasive vascular imaging. We therefore investigated whether MRI provides valuable information about the characteristics of atherosclerotic vessels using rabbit models of macrophage-rich or SMC-rich atherosclerotic arteries.

MR virtual endoscopy for biliary tract and pancreatic duct.

Developments in magnetic resonance (MR) equipment and techniques have been remarkable. Especially, respiratory-triggered three-dimensional MR cholangiopancreatography (3D-MRCP) has been developed to provide images with high spatial resolution of the biliary tract and pancreatic duct. These 3D data can be employed in MR virtual endoscopy (MRVE) with volume rendering to visualize the lumina of the gallbladder, bile duct, and pancreatic duct.

[Clinical efficacy of 3D-MR cholangiopancreatography (MRCP) with the T2Plus technique].

The T2Plus technique is an MR method in which longitudinal magnetization is recovered by the application of a -90 degrees radiofrequency pulse in the recovery period after data acquisition. The present study was performed to evaluate the efficacy of the 3D-fast advanced spin echo (FASE) sequence with T2Plus technique in improving the image quality of respiratory-triggered 3D-MRCP. We performed a phantom study and clinical study in 60 cases.

[Usefulness of the opposite direction for Stenvers' method].

In otorthinolaryngology, Stenvers' method is employed in radiography of the pyramid (internal acoustic meatus and semicircular canals). However, in cases of dizziness, where the prone position is difficult to achieve, we occasionally use the opposite Stenvers' method instead of the conventional one. This makes it possible to perform radiography with the patient in the supine position.