No abstract available.
Humans ; Magnetic Resonance Imaging*

Metaphyseal cysts are common findings in Legg-Calv Perthes(LCP) disease, though usually disappear within 6-12 months. Several studies have described the MR imaging findings of these cysts, though serial MRI findings have not been documented. In this report, therefore, we report the serial MRI results of metaphyseal cyst in LCP patients.
Humans ; Magnetic Resonance Imaging

No abstract available.
Magnetic Resonance Imaging* ; Neurons*

No abstract available.
Abscess* ; Magnetic Resonance Imaging*

Magnetic resonance imaging with its superior soft tissue contrast resolution and absence of beam hardening artifacts, combined with its ability to perform multiplanar imaging, is now effective tool in diagnostic imagings. Magnetic resonance is primarily a phenomenon that involves atomic nuclei. It provides totally new clinical informations with no known hazards through the use of very weak interactions with endogenous stable magnetic atomic nuclei. This article briefly summarized the basic mechanism of generation and detection of the signals and general sorts of tissue properties which can influence the signals and thereby give rise to tissue contrast. It also describes how the machine-operating parameters can be used to manipulate the tissue contrast observed in the image.
Artifacts ; Magnetic Resonance Imaging*

Functional magnetic resonance imaging is a promising imaging technique developed recently to obtain functional maps of the brain, and can be successfully performed on widely available diagnostic MR imaging systems. Thus, the technical principle and application of this new imaging are no more minor part of knowledge in radiology. We describe herein the overview of functional magnetic resonance imaging about the physiologic mechanism, imaging technique, image-processing method and practical application.
Brain* ; Magnetic Resonance Imaging*

No abstract available.
Magnetic Resonance Imaging*

No abstract available.
Magnetic Resonance Imaging*

The use of both magnetic resonance imaging (MRI) and pacing devices has vastly increased worldwide in recent years. A significant number of implanted patients will likely need monitoring using magnetic resonance imaging (MRI) over the course of the lifetime of their device. Some studies have demonstrated that with appropriate precautions, MRI can be safely performed in patients with selected implantable pacemakers. However, MRI is still contraindicated in patients with pacemakers. Recently, new pacing systems have been specifically designed for safe use in the MRI environment. The first reported experience suggests that the technology is safe and may allow patients with these new pacemakers to undergo MRI. This review will describe the outstanding issues and controversies surrounding the safety of MRI in patients with pacemakers, and the potential benefits of the new MRI-conditional technology. We will also discuss how to decide whether an MRI-conditional system should be implanted, and highlight key issues that warrant further studies.
Humans ; Magnetic Resonance Imaging*

PURPOSE: A new compressed sensing technique by iterative truncation of small transformed coefficients (ITSC) is proposed for fast cardiac CINE MRI. MATERIALS AND METHODS: The proposed reconstruction is composed of two processes: truncation of the small transformed coefficients in the r-f domain, and restoration of the measured data in the k-t domain. The two processes are sequentially applied iteratively until the reconstructed images converge, with the assumption that the cardiac CINE images are inherently sparse in the r-f domain. A novel sampling strategy to reduce the normalized mean square error of the reconstructed images is proposed. RESULTS: The technique shows the least normalized mean square error among the four methods under comparison (zero filling, view sharing, k-t FOCUSS, and ITSC). Application of ITSC for multi-slice cardiac CINE imaging was tested with the number of slices of 2 to 8 in a single breath-hold, to demonstrate the clinical usefulness of the technique. CONCLUSIONS: Reconstructed images with the compression factors of 3-4 appear very close to the images without compression. Furthermore the proposed algorithm is computationally efficient and is stable without using matrix inversion during the reconstruction.
Magnetic Resonance Imaging, Cine*