One study showed that FDG-PET/CT detected clinically unsuspected sites of extracardiac infection in up to 24% of cases [52]. Several single-center studies have shown promise in identifying cardiovascular implantable electronic device infections using FDG-PET/CT with sensitivities ranging from 60% to 100% and specificities ranging from 86% to 100% [4,53-55]. In cases in which TTE and TEE were normal or equivocal, 2 studies showed that FDG-PET/CT was able to detect periprosthetic abscesses [56,57], which has been shown to occur in nearly 30% of cases [47]. Fluoroscopy Heart Cardiac fluoroscopy may be indicated for evaluating mechanical prosthetic cardiac valves afflicted with endocarditis [35]. Valve fluoroscopy is used to detect excess mobility of the mechanical prosthetic valve during the cardiac cycle (a finding highly suggestive of valve dehiscence due to infective endocarditis) or to detect immobility of mechanical prosthetic valve leaflets secondary to infected pannus or thrombus. WBC Scan Heart WBCs may be labeled with either In-111, Tc-99m, or Ga-67 [36]. This may be used for identifying and localizing infected vegetations and paravalvular abscesses [39,58]. When echocardiography is inconclusive in suspected prosthetic valve endocarditis, a WBC scan has been shown to have a lower sensitivity than FDG-PET/CT (64% versus 93%, respectively) but a higher specificity (100% versus 71%, respectively) for the diagnosis of endocarditis [39,59]. Radiography Chest The chest radiograph is used to determine cardiac chamber size and the presence and severity of pulmonary venous hypertension and edema. It is also used to monitor the severity of the hemodynamic consequences of valvular regurgitation caused by infective endocarditis and to assess the response to treatment. In right-sided endocarditis, the chest radiograph may be effective in demonstrating pulmonary infarcts and abscesses as sequelae of septic emboli. Infective Endocarditis
Infective Endocarditis. One study showed that FDG-PET/CT detected clinically unsuspected sites of extracardiac infection in up to 24% of cases [52]. Several single-center studies have shown promise in identifying cardiovascular implantable electronic device infections using FDG-PET/CT with sensitivities ranging from 60% to 100% and specificities ranging from 86% to 100% [4,53-55]. In cases in which TTE and TEE were normal or equivocal, 2 studies showed that FDG-PET/CT was able to detect periprosthetic abscesses [56,57], which has been shown to occur in nearly 30% of cases [47]. Fluoroscopy Heart Cardiac fluoroscopy may be indicated for evaluating mechanical prosthetic cardiac valves afflicted with endocarditis [35]. Valve fluoroscopy is used to detect excess mobility of the mechanical prosthetic valve during the cardiac cycle (a finding highly suggestive of valve dehiscence due to infective endocarditis) or to detect immobility of mechanical prosthetic valve leaflets secondary to infected pannus or thrombus. WBC Scan Heart WBCs may be labeled with either In-111, Tc-99m, or Ga-67 [36]. This may be used for identifying and localizing infected vegetations and paravalvular abscesses [39,58]. When echocardiography is inconclusive in suspected prosthetic valve endocarditis, a WBC scan has been shown to have a lower sensitivity than FDG-PET/CT (64% versus 93%, respectively) but a higher specificity (100% versus 71%, respectively) for the diagnosis of endocarditis [39,59]. Radiography Chest The chest radiograph is used to determine cardiac chamber size and the presence and severity of pulmonary venous hypertension and edema. It is also used to monitor the severity of the hemodynamic consequences of valvular regurgitation caused by infective endocarditis and to assess the response to treatment. In right-sided endocarditis, the chest radiograph may be effective in demonstrating pulmonary infarcts and abscesses as sequelae of septic emboli. Infective Endocarditis