[en] The aim of the article is to systematically review published data about the comparison between positron emission tomography (PET) or PET/computed tomography (PET/CT) using Fluorine-18-Fluorodeoxyglucose (FDG) and whole-body magnetic resonance imaging (WB-MRI) in patients with different tumours. A comprehensive literature search of studies published in PubMed/MEDLINE, Scopus and Embase databases through April 2012 and regarding the comparison between FDG-PET or PET/CT and WB-MRI in patients with various tumours was carried out. Forty-four articles comprising 2287 patients were retrieved in full-text version, included and discussed in this systematic review. Several articles evaluated mixed tumours with both diagnostic methods. Concerning the specific tumour types, more evidence exists for lymphomas, bone tumours, head and neck tumours and lung tumours, whereas there is less evidence for other tumour types. Overall, based on the literature findings, WB-MRI seems to be a valid alternative method compared to PET/CT in oncology. Further larger prospective studies and in particular cost-effectiveness analysis comparing these two whole-body imaging techniques are needed to better assess the role of WB-MRI compared to FDG-PET or PET/CT in specific tumour types

[en] Sarcoidosis is a multisystem chronic inflammatory disease of unknown etiology characterized by widespread growth of non-caseating granulomas. The diagnosis of sarcoidosis is based on clinical and imaging presentation, histologic confirmation and the absence of alternative diseases. Radiology and Nuclear Medicine play an essential role in the diagnostic work-up of patients with sarcoidosis to assess disease extent and activity. In addition, imaging modalities have shown their potential in managing these patients in terms of treatment response and prognostic assessment. Sarcoidosis has a predilection for chest involvement, showing typical and atypical manifestations in the lungs, airways and hilar/mediastinal lymph nodes. Chest radiography (X-ray) still plays an important role in suggesting diagnosis for cases with typical presentation of sarcoidosis, while computed tomography (CT) has higher accuracy in detecting early stage disease and in narrowing differential diagnosis, particularly in atypical manifestations. For extrathoracic involvement, both CT and MR (magnetic resonance) have comparable performance even though MR is the modality of choice for assessing neurosarcoidosis and cardiac sarcoidosis. In the last decades positron emission tomography/CT (PET/CT) has demonstrated an increasing and relevant value in assessing disease extent and activity, treatment planning and therapy response, with a crucial role in the management of cardiac sarcoidosis. In this article, an overview of the possible imaging manifestations of thoracic and extrathoracic sarcoidosis and current concepts on staging, response assessment and prognosis is provided. Finally, the potential applications of non-FDG radiotracers is briefly discussed.