Transcranial Doppler of a paradoxical brain embolism associated with a pulmonary arteriovenous fistula.

We herein report the case of a patient who had paradoxical brain embolism owing to a pulmonary arteriovenous fistula (PAVF) who was diagnosed as having a right-to-left shunt by transcranial Doppler (TCD) with saline contrast medium. TCD with saline contrast medium failed to detect any high-intensity transient signals immediately after catheter embolization of the PAVF. Thus, TCD with saline contrast medium was useful for identifying the presence of a right-to-left shunt and for confirming that the shunt had been obliterated after endovascular treatment.