Comparison Of Two Contrast Agents For Right-to-left Shunt Diagnosis With Contrast-enhanced Transcranial Doppler

Background and purpose：We compared the efficacy of two contrast agents (CAs), namely agitated saline(AS) and AS with blood (ASb), for the diagnosis of right-to-left shunt (RLS) bycontrast-enhanced transcranial Doppler (c-TCD).Object and Methods:Three hundred and thirty Chinese patients underwent examinations with each offour different methods in a randomized order as follows:(1)9mL saline solution with1mL air, without Valsalva maneuver (VM)(ASwoVM);(2)9mL saline solution with1mL air, with VM (ASwVM);(3)9mL saline solution,1mL air, and a drop of thepatient’s blood, without VM (ASbwoVM); and (4)9mL saline solution,1mL air, anda drop of the patient’s blood, with VM (ASbwVM).Results:The positive rates of detection were11.5%,17.9%,16.7%, and23.6%forASwoVM, ASwVM, ASbwoVM, and ASbwVM, respectively. The microbubblenumbers were4.0±1.83,11.5±6.2,10.5±4.9, and33.7±14.9, respectively. Therewere significant differences between the four groups (all comparisons, p <0.01).Conclusions：contrast-enhanced transcranial Doppler with agitated saline with blood gotbetter positive rates of diagnosis of right-to-left shunt than those obtained withagitated saline alone.