title: Effects of patient position on right-to-left shunt detection by contrast transcranial Doppler.
abstract: Contrast-enhanced transcranial Doppler (c-TCD) was performed on 117 patients to detect a right-to-left shunt (RLS). Each patient was examined during normal breathing and after performing the Valsalva maneuver (VM) in three randomly ordered positions: supine, left lateral decubitus and sitting upright. When breathing normally, RLS-positive rates were 15.4%, 23.1% and 28.2% for supine, left lateral decubitus and upright sitting positions, respectively. After VM, the positive rates were 25.6%, 28.2% and 36.8%, respectively. For each position, the RLS-positive rates were higher after VM than normal breathing and higher for the left lateral decubitus and upright sitting positions compared with the supine position, irrespective of breathing. There were no significant differences between findings for the left lateral decubitus and upright sitting positions. No significant differences in shunt grades were found across all groups. The choice of position for patients undergoing c-TCD can improve its sensitivity for the diagnosis of RLS.
authors: The Neuroscience Center, Department of Neurology, First Norman Bethune Hospital of Jilin University, Changchun, China.
authors: Chun-Tao
authors: CT
authors: Wu
authors: The Neuroscience Center, Department of Neurology, First Norman Bethune Hospital of Jilin University, Changchun, China.
authors: Ke
authors: K
authors: Han
authors: The Neuroscience Center, Department of Neurology, First Norman Bethune Hospital of Jilin University, Changchun, China.
authors: Zhen-Ni
authors: ZN
authors: Guo
authors: The Neuroscience Center, Department of Neurology, First Norman Bethune Hospital of Jilin University, Changchun, China.
authors: Yi
authors: Y
authors: Yang
authors: Department of Cardiac Surgery, First Norman Bethune Hospital of Jilin University, Changchun, China.
authors: Yong-Sheng
authors: YS
authors: Gao
authors: The Neuroscience Center, Department of Neurology, First Norman Bethune Hospital of Jilin University, Changchun, China.
authors: Jing
authors: J
authors: Bai
authors: The Neuroscience Center, Department of Neurology, First Norman Bethune Hospital of Jilin University, Changchun, China. Electronic address: xingyq2009@sina.com.
authors: Ying-Qi
authors: YQ
authors: Xing
mesh_terms: D000328:Adult; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D008297:Male; D056888:Patient Positioning; D017585:Ultrasonography, Doppler, Transcranial; D014636:Valsalva Maneuver
chemical_list: D003287:Contrast Media
keywords: Contrast-enhanced transcranial Doppler; Left lateral decubitus; Right-to-left shunt; Supine; Upright sitting