Radiographics : a review publication of the Radiological Society of North America, Inc
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Whole-body imaging, in particular molecular imaging with fluorine 18 ((18)F)-fluorodeoxyglucose (FDG) positron emission tomography (PET), is essential to management of lymphoma. The assessment of disease extent provided by use of whole-body imaging is mandatory for planning appropriate treatment and determining patient prognosis. Assessment of treatment response allows clinicians to tailor the treatment strategy during therapy if necessary and to document complete remission at the end of treatment. ⋯ Because of their high cellularity and high nucleus-to-cytoplasm ratio, lymphomatous lesions have low ADC values and appear hypointense on ADC maps. As a result, whole-body DW MR imaging with ADC mapping has become a promising tool for lymphoma staging and treatment response assessment. The authors review their 4 years of experience with 1.5-T and 3-T whole-body DW MR imaging used with (18)F-FDG PET/computed tomography at baseline, interim, and end of treatment in patients with Hodgkin lymphoma and diffuse large B-cell lymphoma and discuss the spectrum of imaging findings and potential pitfalls, limitations, and challenges associated with whole-body DW MR imaging in these patients.
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Cardiac sarcoidosis is a rare but potentially fatal disorder with a nonspecific spectrum of clinical manifestations, including conduction disorders, congestive heart failure, ventricular arrhythmias, and sudden cardiac death. Although early treatment to improve morbidity and mortality is desirable, sensitive and accurate detection of cardiac sarcoidosis remains a challenge. Except for the histopathologic finding of noncaseating granulomas in an endomyocardial biopsy specimen, most diagnostic tests are limited and nonspecific at best. ⋯ Advanced imaging modalities, such as cardiac magnetic resonance imaging and positron emission tomography with fluorodeoxyglucose, have become increasingly useful in facilitating diagnosis and therapeutic monitoring, although limited prospective studies exist. This article describes the clinical parameters and pathologic findings of cardiac sarcoidosis and the advanced imaging features and differential diagnostic challenges that must be considered for a successful diagnostic approach. In addition, to improve the understanding of abnormalities detected with different imaging modalities, we suggest a unified terminology in describing radiologic findings related to cardiac sarcoidosis.