Online evaluation of fetal second-trimester four-chamber view images: a comparison of six evaluation methods

To compare six online evaluation methods for auditing routine second-trimester four-chamber view still images.

We evaluated three different scoring grids (subjective, five-item score and seven-item score), which were applied with or without access to online help, resulting in a total of six evaluation methods. For the subjective scoring grid, images were rated as excellent, good, fair, poor or very poor. For the five-item score, 1 point was allocated for visualization (vs non-visualization or non-evaluable) of each of: heart crux, atria, ventricles, apex and aorta, yielding a score of 0-5. For the seven-item score, 1 point was allocated for clear (vs unclear) visualization of each of: moderator band at the apex, interventricular septum, atrioventricular valves, non-linear insertion of atrioventricular valves (normal offset), septum primum, aorta and pulmonary vein. Each evaluation method was used via the Internet by three randomly selected reviewers, who evaluated the same set of 80 images. Reviewers were experienced in fetal ultrasound, but were not involved in the design of the study. Interrater agreement was the main outcome.

The five-item scoring grid with online help achieved the best interrater agreement (interrater intraclass correlation coefficient = 0.7).

Evaluation of the second-trimester sonographic four-chamber view is apparently best achieved with a simple five-item scoring grid.