Abstract
BackgroundContrast-enhanced ultrasound (CEUS) has recently been proposed as a minimally- invasive, alternative method for blood volume measurement. This study aims at comparing the accuracy of CEUS and the classical thermodilution techniques for volume assessment in an in-vitro set-up.MethodsThe in-vitro set-up consisted of a variable network between an inflow and outflow tube and a roller pump. The inflow and outflow tubes were insonified with an ultrasound array transducer and a thermistor was placed in each tube. Indicator dilution curves were made by injecting indicator which consisted of an ultrasound-contrast-agent diluted in ice-cold saline. Both acoustic intensity- and thermo-dilution curves were used to calculate the indicator mean transit time between the inflow and outflow tube. The volumes were derived by multiplying the estimated mean transit time by the flow rate. We compared the volumes measured by CEUS with the true volumes of the variable network and those measured by thermodilution by Bland-Altman and intraclass-correlation analysis.ResultsThe measurements by CEUS and thermodilution showed a very strong correlation (rs = 0.94) with a modest volume underestimation by CEUS of −40 ± 28 mL and an overestimation of 84 ± 62 mL by thermodilution compared with the true volumes. Both CEUS and thermodilution showed a high statistically significant correlation with the true volume (rs = 0.97 (95% CI, 0.95 - 0.98; P<0.0001) and rs = 0.96 (95% CI, 0.94 - 0.98; P<0.0001, respectively).ConclusionsCEUS volume estimation provides a strong correlation with both the true volumes in-vitro and volume estimation by thermodilution. It may therefore represent an interesting alternative to the standard, invasive thermodilution technique.
Highlights
Contrast-enhanced ultrasound (CEUS) has recently been proposed as a minimally- invasive, alternative method for blood volume measurement
The median volumes estimated with the thermodilution technique double fit method and impulse response method were 722 (489 – 944) mL and 693 (459 – 886) mL, respectively
In the present study, comparing volume measurement by CEUS with thermodilution in a controlled in-vitro set-up, we have demonstrated that there is a good correlation between volumes measured by CEUS and by thermodilution
Summary
Contrast-enhanced ultrasound (CEUS) has recently been proposed as a minimally- invasive, alternative method for blood volume measurement. This study aims at comparing the accuracy of CEUS and the classical thermodilution techniques for volume assessment in an in-vitro set-up. The postoperative phase and heart failure, circulating volume can be difficult to assess and in these cases classical dilution techniques are of additional value. Downstream, the indicator concentrationchange over time is measured at a detection site to create an indicator dilution curve (IDC) [4]. The IDC is used to estimate the mean transit time (MTT); this is the average time it takes for the indicator to travel from the injection site to the detection site [5]. The transpulmonary thermodilution technique allows measurement of cardiac output (CO) and intrathoracic blood volumes [3,6]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
