Objective
Echocardiography with conventional colour Doppler has technical limitations, which may impede flow visualisation in the pulmonary veins.
Blood Flow Imaging is a new ultrasound modality which supplements colour Doppler with angle-independent information of flow direction that is not influenced by velocity aliasing. This is done by visualising an additional blood speckle movement superimposed on the colour Doppler images. The aim of this study was to investigate if this method improves the visualisation of the pulmonary veins.

Methods
Twenty six neonates with suspected congenital heart disease were included prospectively and examined with echocardiography following parental consent. Imaging of the pulmonary veins with Blood Flow Imaging was added to the standard examination.
For each patient, Blood Flow Imaging and colour Doppler imaging cine loops were presented to four echo cardiographers (paediatric cardiologist/cardiologists) in a random fashion. Information regarding the venous connections, flow direction, and the overall quality of the image was evaluated on a visual analogue scale from 0 (worst) to 100 (best). The ratings were compared within each observers using Wilcoxon’s exact signed-rank test.

Results
Blood Flow Imaging was consistently ranked as better than colour Doppler imaging. With respect to visualisation of the pulmonary venous connections, blood flow direction and the overall quality, the median difference in favour of blood flow imaging was 6, 12, and 22 on the visual analogue scale, respectively (all p-values < 0.01).

Conclusion
Blood Flow Imaging may improve the visualisation of the pulmonary veins in neonates.