Radiographics : a review publication of the Radiological Society of North America, Inc
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Ingested and aspirated foreign bodies are a common occurrence in children and are important causes of morbidity and mortality in the pediatric population. Imaging plays an important role in the diagnosis of ingested and aspirated foreign bodies in children and can be crucial to guiding the clinical management of these patients. Prompt identification and localization of ingested foreign bodies is essential to determining the appropriate treatment, as several types of commonly ingested foreign bodies require urgent removal and others can be managed conservatively. ⋯ Prompt recognition of secondary radiographic signs of foreign-body aspiration is also crucial, as clinical symptoms can sometimes be nonspecific and most aspirated foreign bodies are radiolucent. Overall, radiography is the most important modality in the evaluation of ingested or aspirated foreign bodies; however, fluoroscopy and computed tomography play an ancillary role in complicated cases. It is essential that every radiologist who interprets imaging examinations of children be aware of the imaging appearances of commonly ingested and aspirated foreign bodies and their clinical significance.
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Body magnetic resonance (MR) imaging is challenging because of the complex interaction of multiple factors, including motion arising from respiration and bowel peristalsis, susceptibility effects secondary to bowel gas, and the need to cover a large field of view. The combination of these factors makes body MR imaging more prone to artifacts, compared with imaging of other anatomic regions. Understanding the basic MR physics underlying artifacts is crucial to recognizing the trade-offs involved in mitigating artifacts and improving image quality. ⋯ Motion artifacts can be overcome through respiratory synchronization, alternative k-space sampling schemes, and parallel imaging. Aliasing and truncation artifacts derive from limitations in digital sampling of the MR signal and can be rectified by adjusting the sampling parameters. Understanding the causes of artifacts and their possible solutions will enable practitioners of body MR imaging to meet the challenges of novel pulse sequence design, parallel imaging, and increasing field strength.
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Amyloidosis is a rare diverse condition caused by the pathologic extracellular deposition of abnormal insoluble proteins throughout the body. It may exist as a primary disease or, more commonly, may be secondary to a wide variety of pathologic processes ranging from chronic infection or inflammation to malignancy. Hereditary forms also exist. ⋯ At cardiac magnetic resonance (MR) imaging, the left ventricular wall is typically thickened, with associated diastolic dysfunction. Delayed contrast material-enhanced cardiac MR imaging typically shows global transmural or subendocardial enhancement. The pathophysiology, classification, treatment, and prognosis of amyloidosis are reviewed, followed by case examples of the appearance of thoracic and cardiac amyloidosis on chest radiographs, computed tomographic (CT) images, and cardiac MR images.