Contrast-enhanced transcranial Doppler ultrasound for diagnosis of patent foramen ovale.
Front Neurol Neurosci
; 21: 206-215, 2006.
Article
en En
| MEDLINE
| ID: mdl-17290139
ABSTRACT
The suspected cause of clinical manifestations of patent foramen ovale (PFO) is a transient or a permanent right-to-left shunt (RLS). Contrast-enhanced transcranial Doppler ultrasound (c-TCD) is a reliable alternative to transesophageal echocardiography (TEE) for diagnosis of PFO, and enables also the detection of extracardiac RLS. The air-containing echo contrast agents are injected intravenously and do not pass the pulmonary circulation. In the presence of RLS, the contrast agents bypass the pulmonary circulation and cause microembolic signals (MES) in the basal cerebral arteries, which are detected by TCD. The two main echo contrast agents in use are agitated saline and D-galactose microparticle solutions. At least one middle cerebral artery (MCA) is insonated, and the ultrasound probe is fixed with a headframe. The monitored Doppler spectra are stored for offline analysis (e.g., videotape) of the time of occurrence and number of MES, which are used to assess the size and functional relevance of the RLS. The examination is more sensitive, if both MCAs are investigated. In the case of negative testing, the examination is repeated using the Valsalva maneuver. Compared to TEE, c-TCD is more comfortable for the patient, enables an easier assessment of the size and functional relevance of the RLS, and allows also the detection of extracardiac RLS. However, c-TCD cannot localize the site of the RLS. Therefore, TEE and TCD are complementary methods and should be applied jointly in order to increase the diagnostic accuracy for detecting PFO and other types of RLS.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Arterias Cerebrales
/
Embolia y Trombosis Intracraneal
/
Ultrasonografía Doppler Transcraneal
/
Medios de Contraste
Tipo de estudio:
Diagnostic_studies
/
Etiology_studies
Límite:
Humans
Idioma:
En
Revista:
Front Neurol Neurosci
Asunto de la revista:
NEUROLOGIA
Año:
2006
Tipo del documento:
Article
País de afiliación:
Suiza