BACKGROUND AND PURPOSE Intravascular treatment of intracranial aneurysms is a relatively new therapeutic technique and long-term controlled angiographic trials are needed to assess persistence of aneurysm occlusion. Our purpose was to evaluate the effectiveness of 3D time-of-flight (3D-TOF) MR angiography as a noninvasive screening tool in the follow-up of cerebral aneurysms treated with Guglie...

Target audience: Radiofrequency (RF) engineers, anyone interested in high field RF coils, parallel transmit or high field brain imaging. Introduction: Electric dipole antennas are seeing increasing use for 7T MR imaging. They differ from conventional surface coil loops in many ways. With 8 elements surrounding a body sized tissue equivalent phantom and array of dipole antennas can achieve highe...

S. Weiss, T. Uelzen, G. Pantel, J. Mueller Philips Research Laboratories, Hamburg, Germany, Department of Micro Systems Technology, Hamburg University of Technology, Hamburg, Germany, MRI Devices Daum GmbH, Schwerin, Germany Objective: The motivation for the application of intravascular imaging coils is to gain high SNR images from a local area. To maximize SNR, proper tuning and matching of su...

Introduction Loop coils are still widely-used MR receivers. The resistance of loop coils is an important factor influencing the signal-to-noise ratio (SNR) in the MR experiment. In some applications, such as small loops, low field, or lifted-off coils [1], coil noise could be the dominant factor determining SNR. Thus it is critical to fully understand components contributing in coil resistance ...

A process for batch fabrication of low-cost needle-shaped micro-coils for magnetic resonance (MR) spectroscopy is demonstrated. The conductors are embedded inside a cross-section designed to avoid the signal cancellation effects that can occur with completely immersed detectors. Simple models are developed for the sensitivity of an immersed coil and for the electrical performance of coils on si...

The value of duplex Doppler sonography as a noninvasive technique for evaluating the carotid neck vessels has been well documented [1-4]. The sensitivity and specificity of duplex Doppler sonography in the detection of high-grade stenosis (greater than 80%) approximates 90% [1] . However, duplex Doppler sonography has several limitations. Plaque ulceration cannot be detected reliably, even with...

The study of the wrist represents a major diagnostic challenge because of its complex anatomy and the small size of individual structures. Recent advances in imaging techniques have increased our diagnostic capabilities. However, 3T magnets, multichannel specific wrist coils, and new MRI sequences have not restricted the indications of arthrographic imaging techniques (CT arthrography and MR ar...

Fifteen patients with orbital neoplasms demonstrated by CT were studied with magnetic resonance (MR) using a 13 cm surface coil and a 0.6 T superconducting magnet. The use of a surface coil allowed for a reduction in slice thickness and a significant improvement in spatial resolution resulting in better demonstration and improved characterization of orbital lesions. All neoplasms (15/15) were d...