title: Transcranial Doppler ultrasonography should it be the first choice for persistent foramen ovale screening?
abstract: BACKGROUND
  Persistent foramen ovale (PFO) is considered a cause of cryptogenic stroke and a risk factor for neurological events in young patients. The reference standard for identifying a PFO is contrast-enhanced transesophageal echocardiography (TEE).The goal of this study was to evaluate the feasibility of transcranial color Doppler (TCD) and its diagnostic sensitivity compared with TEE.
  
  
  METHODS
  We investigated 420 patients admitted to our department with cryptogenic stroke, transient ischemic attacks or other neurological symptoms. All patients underwent TCD and TEE evaluation. TCD and TEE examinations were performed according to a standardized procedure: air-mixed saline was injected into the right antecubital vein three times, while the Doppler signal was recorded during the Valsalva maneuver. During TCD the passage of contrast into the right-middle cerebral artery was recorded 25 seconds following the Valsalva maneuver.
  
  
  RESULTS
  We detected a right-to-left shunt in 220 patients (52.3%) and no-shunts in 159 patients (37.9%) with both TCD and TEE. In 20 (4.8%) patients TEE did not reveal contrast passage which was then detected by TCD. In 21 (5.0%) patients only TEE revealed a PFO. The feasibility of both methods was 100%. TCD had a sensitivity of 95% and a specificity of 92% in the diagnosis of PFO.
  
  
  CONCLUSIONS
  TCD has a relatively good sensitivity and specificity. TCD and TEE are complementary diagnostic tests for PFO, but TCD should be recommended as the first choice for screening because of its simplicity, non-invasive character, low cost and high feasibility.
authors.affiliation: Department of Cardiac and Vascular Diseases, John Paul II Hospital, Institute of Cardiology, Collegium Medicum, Jagiellonian University, Krakow, Poland. moni_s@interia.pl.
authors.forename: Monika
authors.initials: M
authors.lastname: Komar
authors.forename: Maria
authors.initials: M
authors.lastname: Olszowska
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Przewłocki
authors.forename: Jakub
authors.initials: J
authors.lastname: Podolec
authors.forename: Jakub
authors.initials: J
authors.lastname: Stępniewski
authors.forename: Bartosz
authors.initials: B
authors.lastname: Sobień
authors.forename: Rafał
authors.initials: R
authors.lastname: Badacz
authors.forename: Anna
authors.initials: A
authors.lastname: Kabłak-Ziembicka
authors.forename: Lidia
authors.initials: L
authors.lastname: Tomkiewicz-Pająk
authors.forename: Piotr
authors.initials: P
authors.lastname: Podolec
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D054092:Foramen Ovale, Patent / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D014636:Valsalva Maneuver; D055815:Young Adult