Background/introduction Magnetic resonance (MR) imaging plays an important role in monitoring thermal treatment. It can quantify thermal dose with temperature maps based on the proton-resonance frequency shift. Volumetric coverage is desirable, but acquiring multiple slices imaging is time consuming. Therefore, accelerated methods are needed to improve the spatial and temporal resolution in MR ...

Magnetic resonance (MR) systems operating at 3 Telsa (T) and above have demonstrated considerable potential in human studies, offering improved signal-to-noise ratio and spectral resolution. However, because of radiofrequency limitations and concerns, and the lack of large volume body coils, most studies have been limited to the head. In this study we describe the design and construction of a t...

Introduction Until recently, in utero fetal magnetic resonance imaging (MRI) had minimal clinical utility due to marked interference from motion artifacts. Technical advances in the MR soft (ultrafast sequences) and hard ware (fast gradients, surface coils) now allow to apply MRI for prenatal diagnosis. The aim of this study was to evaluate the ultrafast, T2weighted single shot fast spin-echo (...

Increased signal intensity on magnetic resonance (MR) imaging of tendons arising from the magic angle phenomenon is well recognized. This study aimed to evaluate the effect of varying the echo time (TE) upon tendon signal intensity, and to determine if a modified TE value produces acceptable T1 and proton density (PD) weighted images. Fresh bovine tendons were imaged in a 1.5 T MR scanner using...

Introduction: Parallel imaging [1,2] is based on the simultaneous measurement of the MR signal with multiple receiver coils. The different sensitivity profiles of the coils modulate the signal of the object in different ways. It is thus possible to accelerate the measurement by compensating a reduction of the number of phase encodings by using spatial information derived from the coils sensitiv...

Introduction In human MRI, it is common to use one radiofrequency coil to produce a homogeneous excitation field, but use a separate surface coil or array of coils for increased detection sensitivity. Multiple-mouse MRI (MMMRI) accelerates preclinical studies by imaging multiple mice simultaneously [1]. Although MMMRI was originally reported using an array of shielded transmit-receive (Tx-Rx) c...

INTRODUCTION: Non-resonance method (NORM) for MR signal excitation and reception has been advocated due to its unmatched advantages in multinuclear and parallel imaging applications (1). In this work, we established a simulation model and systematically investigated the reception efficiency and SNR of the NORM technology using numerical analysis and in vivo MR imaging. The results were validate...

Numerical methods based on solutions of Maxwell’s equations are usually adopted for the electromagnetic characterization of Magnetic Resonance (MR) Radiofrequency (RF) coils. In this context, many different numerical methods can be employed, including time domain methods, e.g., the Finite-Difference Time-Domain (FDTD), and frequency domain methods, e.g., the Finite Element Methods (FEM) and the...

BACKGROUND Catheter visualization and tracking remains a challenge in interventional MR.Active guidewires can be made conspicuous in "profile" along their whole shaft exploiting metallic core wire and hypotube components that are intrinsic to their mechanical performance. Polymer-based catheters, on the other hand, offer no conductive medium to carry radio frequency waves. We developed a new "a...

BACKGROUND AND PURPOSE Intra-arterial contrast angiographies are generally used to confirm treatment results of endovascular neurointerventions such as aneurysm obliteration. We compared MR angiography with digital subtraction angiography (DSA) as a follow-up technique for the detection of aneurysmal remnant cavities and arterial patency in patients treated for intracranial aneurysms with Gugli...