title: Body positions in the diagnosis of right-to-left shunt by contrast transcranial Doppler.
abstract: Contrast transcranial Doppler (c-TCD) is sensitive in detecting right-to-left shunt (RLS). However, the methodology and ideal posture are controversial. Consecutive migraine patients were prospectively examined for RLS using c-TCD. Each patient was examined while at rest and subsequently with the Valsalva maneuver (VM) in three positions: supine, left lateral decubitus and right lateral decubitus. RLS was diagnosed with at least one microbubble detected at any position. RLS was highest in the left lateral decubitus position, both during rest and with VM. The left lateral decubitus position was associated with the highest total number of microbubbles and greater shunt grades. Patients who tested positive in the other two positions had the lowest index position failure rate during rest in the left lateral decubitus position. In some patients in whom RLS is detected at rest, it may not be detected (false negative) under VM. To ensure c-TCD's the sensitivity to RLS, testing in the left lateral decubitus position at rest and under VM is suggested; testing in other positions is necessary to avoid false negatives.
authors.affiliation: Department of Neurology, First Hospital of Jilin University, Changchun, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Han
authors.affiliation: Department of Neurology, First Hospital of Jilin University, Changchun, China.
authors.forename: Yingqi
authors.initials: Y
authors.lastname: Xing
authors.affiliation: Department of Neurology, First Hospital of Jilin University, Changchun, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Neurology, Kaohsiung Medical University Hospital and Department of Neurology, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: A-Ching
authors.initials: AC
authors.lastname: Chao
authors.affiliation: Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Wen-Yung
authors.initials: WY
authors.lastname: Sheng
authors.affiliation: Graduate Institute of Clinical Medicine and Department of Neurology, College of Medicine, Taipei Medical University and Hospital, Taipei, Taiwan.
authors.forename: Han-Hwa
authors.initials: HH
authors.lastname: Hu
authors.affiliation: Department of Neurology, First Hospital of Jilin University, Changchun, China. Electronic address: doctorwujiang@sina.cn.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
mesh_terms: D000328:Adult; D003287:Contrast Media; D005260:Female; D054092:Foramen Ovale, Patent / Q000150:complications* / Q000000981:diagnostic imaging*; D006801:Humans; D020766:Intracranial Embolism / Q000000981:diagnostic imaging* / Q000209:etiology*; D008297:Male; D056888:Patient Positioning / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017585:Ultrasonography, Doppler, Transcranial / Q000379:methods*; D014636:Valsalva Maneuver
chemical_list: D003287:Contrast Media
keywords: Contrast transcranial Doppler; Patent foramen ovale; Position; Right-to-left shunt