Blood flow imaging - A new angle-independent ultrasound modality for the visualization of flow in atrial septal defects in children

Abstract

Background: Color Doppler imaging (CDI) is the most applied method for evaluation of flow in atrial septal defects (ASD). A new real time ultrasound flow imaging modality called blood flow imaging (BFI) is able to visualize the blood flow in any direction of the image and is not limited by velocity aliasing. The method thereby overcomes the two limitations most often encountered in CDI. In this study we compared BFI with CDI for the visualization of interatrial blood flow in children. Methods: We studied ASD flow in 13 children using both CDI and BFI in the same examination. CDI and BFI cineloops were prepared off-line and both optimal and suboptimal (increased color artifacts) images were presented in random order to four observers. They were asked to range from 0-100 on a visual analogue scale how certain they were of interatrial blood flow. The CDI and BFI ratings were compared using the exact Wilcoxon signed rank test for paired samples. Results: All ASDs visualized with CDI were confirmed using BFI. Two of the observers ranked BFI as being significantly better than CDI when the images were optimized. When the images were suboptimal three of the observers rated BFI as being significantly better. Conclusions: This pilot study indicates that BFI improves the visualization of interatrial blood flow in children. To include BFI in the ordinary echocardiography examination is easy and not time consuming. The method may prove to be a useful supplement to CDI in ASD imaging. © 2007, the Authors.