Body Positions in the Diagnosis of Right-to-Left Shunt by Contrast Transcranial Doppler

Ke Han, Yingqi Xing, Yi Yang, A. Ching Chao, Wen Yung Sheng, Han Hwa Hu, Jiang Wu

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)2376-2381
Number of pages6
JournalUltrasound in Medicine and Biology
Issue number9
Publication statusPublished - Sept 1 2015


  • Contrast transcranial Doppler
  • Patent foramen ovale
  • Position
  • Right-to-left shunt

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Biophysics
  • Acoustics and Ultrasonics


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