Radiographics : a review publication of the Radiological Society of North America, Inc
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Dual-energy (DE) computed tomography (CT) offers the opportunity to generate material-specific images on the basis of the atomic number Z and the unique mass attenuation coefficient of a particular material at different x-ray energies. Material-specific images provide qualitative and quantitative information about tissue composition and contrast media distribution. The most significant contribution of DE CT-based material characterization comes from the capability to assess iodine distribution through the creation of an image that exclusively shows iodine. ⋯ The ability to obtain material-specific images from a single, contrast-enhanced CT acquisition can complement the anatomic knowledge with functional information, and may be used to reduce the radiation dose by decreasing the number of phases in a multiphasic CT examination. DE CT also enables generation of energy-specific and virtual monochromatic images. Clinical applications of DE CT leverage both material-specific images and virtual monochromatic images to expand the current role of CT and overcome several limitations of single-energy CT. (©)RSNA, 2016.
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Cranial nerve disorders are uncommon disease conditions encountered in pediatric patients, and can be categorized as congenital, inflammatory, traumatic, or tumorous conditions that involve the cranial nerve itself or propagation of the disorder from adjacent organs. However, determination of the normal course, as well as abnormalities, of cranial nerves in pediatric patients is challenging because of the small caliber of the cranial nerve, as well as the small intracranial and skull base structures. With the help of recently developed magnetic resonance (MR) imaging techniques that provide higher spatial resolution and fast imaging techniques including three-dimensional MR images with or without the use of gadolinium contrast agent, radiologists can more easily diagnose disease conditions that involve the small cranial nerves, such as the oculomotor, abducens, facial, and hypoglossal nerves, as well as normal radiologic anatomy, even in very young children. ⋯ Therefore, radiologists should be familiar not only with the various diseases that cause cranial nerve dysfunction, and the entire course of each cranial nerve including the intra-axial nuclei and fibers, but also the technical considerations for optimal imaging of pediatric cranial nerves. In this article, we briefly review normal cranial nerve anatomy and imaging findings of various pediatric cranial nerve dysfunctions, as well as the technical considerations of pediatric cranial nerve imaging. Online supplemental material is available for this article. (©)RSNA, 2016.
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The 2012 revised Atlanta classification is an update of the original 1992 Atlanta classification, a standardized clinical and radiologic nomenclature for acute pancreatitis and associated complications based on research advances made over the past 2 decades. Acute pancreatitis is now divided into two distinct subtypes, necrotizing pancreatitis and interstitial edematous pancreatitis (IEP), based on the presence or absence of necrosis, respectively. The revised classification system also updates confusing and sometimes inaccurate terminology that was previously used to describe pancreatic and peripancreatic collections. ⋯ After this time, APFCs or ANCs may either resolve or persist, developing a mature wall to become a pseudocyst or a WON, respectively. Any collection subtype may become infected and manifest as internal gas, though this occurs most commonly in necrotic collections. In this review, the authors present a practical image-rich guide to the revised Atlanta classification system, with the goal of fostering implementation of the revised system into radiology practice, thereby facilitating accurate communication among clinicians and reinforcing the radiologist's role as a key member of a multidisciplinary team in treating patients with acute pancreatitis. (©)RSNA, 2016.
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Acute thoracic symptoms are common among adults visiting emergency departments in the United States. Adults with these symptoms constitute a large burden on the overall resources used in the emergency department. The wide range of possible causes can make a definitive diagnosis challenging, even after clinical evaluation and initial laboratory testing. ⋯ Additional US examinations of the inferior vena cava for noninvasive volume assessment and of the groin areas for detection of deep venous thrombosis are often performed at the same time. This multiorgan US approach can provide valuable information for emergency treatment of both traumatic and nontraumatic thoracic diseases involving the lungs, pleura, chest wall, heart, and vascular system. Online supplemental material is available for this article. (©)RSNA, 2016.
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The adult uterine cervix may exhibit a wide variety of pathologic conditions that include benign entities (eg, cervicitis, hyperplasia, nabothian cysts, cervical polyps, leiomyomas, endometriosis, and congenital abnormalities) as well as malignant lesions, particularly cervical carcinoma. In addition, lesions that arise in the uterine body may secondarily involve the cervix, such as endometrial carcinoma and prolapsed intracavitary masses. Many of these conditions can be identified and characterized at ultrasonography (US), which is considered the first-line imaging examination for the female pelvis. ⋯ This review describes the normal appearance of the cervix at US, the appearance of cervical lesions and conditions that mimic abnormalities at US, and optimal US techniques for evaluation of the cervix. This information will help radiologists detect and diagnose cervical abnormalities more confidently at pelvic US. Online supplemental material is available for this article.