title: Bubble stream reveals functionality of the right-to-left shunt: detection of a potential source for air embolism.
abstract: The existence of a right-to-left shunt may increase the likelihood of micro-embolism by allowing a flux of bubbles under hyperbaric conditions. The aim of the study was to measure the relationship between these shunts and bubbles in 10 consecutive subjects using trans-thoracic and trans-esophageal echocardiography. In video frames, all cardiac chambers were segmented and bubbles were analyzed by our proposed method and two other methods. The relationship with bubbles and shunts was divided into three classes: no bubbles, 1-20 bubbles, >20 bubbles and measured over 2160 frames. Our sensitivity was 100% and our specificity was between 90.1% and 96.4%. There were 4.32-23.78 bubbles/frame in the left atrium according to our method. After the automatic analysis, shunts were graded double-blinded by two cardiologists. Consequently, we noted that aperture size does not necessarily reflect how active the right-to-left shunt is. Instead, our proposed decay curves constitute a better tool for determining functionality.
authors.affiliation: Institute of Biomedical Engineering, Boğaziçi University, Istanbul, Turkey; Department of Computer Engineering, Galatasaray University, Istanbul, Turkey. Electronic address: bparlak@gsu.edu.tr.
authors.forename: Ismail Burak
authors.initials: IB
authors.lastname: Parlak
authors.affiliation: Department of Computer Engineering, Galatasaray University, Istanbul, Turkey; Divers Alert Network Europe- Research Committee, B-1600 Brussels, Belgium.
authors.forename: Salih Murat
authors.initials: SM
authors.lastname: Egi
authors.affiliation: Institute of Biomedical Engineering, Boğaziçi University, Istanbul, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Ademoglu
authors.affiliation: Divers Alert Network Europe- Research Committee, B-1600 Brussels, Belgium; Centre for Hyperbaric Oxygen Therapy, Military Hospital, B-1120 Brussels, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Germonpré
authors.affiliation: Istanbul Memorial Hospital, Istanbul, Turkey.
authors.forename: Ozlem Batukan
authors.initials: OB
authors.lastname: Esen
authors.affiliation: Divers Alert Network Europe- Research Committee, B-1600 Brussels, Belgium.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Marroni
authors.affiliation: Divers Alert Network Europe- Research Committee, B-1600 Brussels, Belgium; Environmental & Occupational Physiology Laboratory, Haute Ecole Paul Henri Spaak, Brussels, Belgium.
authors.forename: Costantino
authors.initials: C
authors.lastname: Balestra
mesh_terms: D000328:Adult; D003287:Contrast Media; D004452:Echocardiography / Q000379:methods*; D004618:Embolism, Air / Q000000981:diagnostic imaging* / Q000209:etiology*; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications* / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D045423:Microbubbles; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: Cardiac patent foramen ovale; Microembolism; Trans-esophageal echocardiography; Trans-thoracic echocardiography