Fever of unknown origin, infection of subcutaneous devices, brain abscesses and endocarditis.

The term 'fever of unknown origin' includes a wide range of conditions that often remain undiagnosed. The possibility of an infection must be promptly diagnosed in order to begin appropriate therapy. Imaging with radiopharmaceuticals, computed tomography, magnetic resonance imaging and ultrasound are the most commonly applied techniques, usually performed in addition to blood tests, biopsies or tissue cultures when required. The lack of comparative studies investigating the accuracy of each radiopharmaceutical for the study of fever of unknown origin was the incentive to perform a meta-analysis of peer articles published between 1981 and 2004 (33 papers) describing the use of nuclear medicine imaging for this purpose. Furthermore, infection of subcutaneous devices, brain abscesses and endocarditis must be considered amongst the causes of fevers of unknown origin. Reviews of 23, 10 and 10 papers, respectively (from 1976 to 2005), were performed on these specific topics. The results may be a useful guide for the choice of the optimal radiopharmaceutical(s) and diagnostic strategy to be applied in each clinical condition and for different aims.