Infectious pseudoaneurysms suspected at echocardiography: electron-beam CT findings

To review the electron-beam computed tomographic (CT) findings in patients with clinical endocarditis and suspected of having perivalvular pseudoaneurysms at echocardiography and to compare these findings with echocardiographic data.

Data on 17 patients who underwent electron-beam CT for suspicion of perivalvular infectious pseudoaneurysm at echocardiography were retrospectively reviewed. Thirteen patients had a history of valvular surgery. Electron-beam CT findings-lesion size, number, extent, and relationships with surrounding structures, and associated lesions-were compared with echocardiographic and surgical and/or autopsy data.

In all patients, electron-beam CT depicted one or more abnormal cavities that filled with contrast material after bolus injection. The mean size (3.5 cm) and number (n = 21) of pseudoaneurysms recorded with electron-beam CT were greater than those recorded with echocardiography (2.9 cm and n = 13, respectively). Associated electron-beam CT findings included valvular vegetations in three patients; mediastinitis in two; and coronary arterial involvement in six. In eight (47%) patients, electron-beam CT depicted a pseudoaneurysm or an additional pseudoaneurysm that was only suspected-not depicted-at echocardiography. Transthoracic and transesophageal echocardiography resulted in underestimation of lesion number, size, and extent and associated lesions, particularly in patients with valvular prostheses or voluminous lesions.

Thoracic infectious pseudoaneurysms are well depicted with electron-beam CT, which may be a useful addition to echocardiography for detection of this disease and thus help in preoperative planning.