Magnetic resonance imaging clinics of North America
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Infections of the brain in the postnatal period differ from those in older children as a result of a combination of distinct epidemiologic factors in general, and immaturity of neonatal brain and immunologic host response in particular. It has been recognized that clinical and neurologic signs are often nonspecific, sometimes scarce, and seldom correlate with the extent of neuroimaging findings, thus warranting an early MR imaging examination in the course of the disease, enabling rapid therapy institution and better clinical outcome. This article reviews most of postnatal pathogen agents involved in neonatal brain infections, related physiopathology, and neuroimaging findings.
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Magn Reson Imaging Clin N Am · Aug 2011
ReviewSkull base, orbits, temporal bone, and cranial nerves: anatomy on MR imaging.
Accurate delineation, diagnosis, and treatment planning of skull base lesions require knowledge of the complex anatomy of the skull base. Because the skull base cannot be directly evaluated, imaging is critical for the diagnosis and management of skull base diseases. ⋯ Thus, CT and MR imaging are often used together for evaluating skull base lesions. This article focuses on the radiologic anatomy of the skull base pertinent to MR imaging evaluation.
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Over the past few decades, spinal magnetic resonance imaging (MR imaging) has largely replaced computed tomography (CT) and CT myelography in the assessment of intraspinal pathology at institutions where MR imaging is available. Given its high contrast resolution, MR imaging allows the differentiation of the several adjacent structures comprising the spine. This article illustrates normal spinal anatomy as defined by MR imaging, describes commonly used spinal MR imaging protocols, and discusses associated common artifacts.
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Magn Reson Imaging Clin N Am · Feb 2011
ReviewBasic concepts of MR imaging, diffusion MR imaging, and diffusion tensor imaging.
MR image contrast is based on intrinsic tissue properties and specific pulse sequences and parameter adjustments. A growing number of MRI imaging applications are based on diffusion properties of water. To better understand MRI diffusion-weighted imaging, a brief overview of MR physics is presented in this article followed by physics of the evolving techniques of diffusion MR imaging and diffusion tensor imaging.
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Magn Reson Imaging Clin N Am · Feb 2011
ReviewDiffusion-weighted magnetic resonance imaging for the evaluation of musculoskeletal tumors.
Conventional MR imaging provides low specificity in the differential diagnosis of musculoskeletal (MSK) tumors and is unable to offer information about the extent of tumoral necrosis and the presence of viable cells, information crucial to assess treatment response and prognosis. Therefore, diffusion-weighted imaging (DWI) is now used with conventional MR imaging to improve diagnostic accuracy and treatment evaluation. This article discusses the technical aspects of DWI, particularly the quantitative and qualitative interpretation of images in MSK tumors. The clinical application of DWI for tumor detection, characterization, differentiation of tumor tissue from others, and assessment of treatment response are emphasized.