Minimum acceptable standards for digital compression of a fetal ultrasoundvideo-clip

If the Internet could be used as a method of transmitting ultrasound images taken in the field quickly and effectively, it would bring tertiary consul tation to even extremely remote centres. The aim of the study was to evalua te the maximum degree of compression of fetal ultrasound video-recordings t hat would not compromise signal quality. A digital fetal ultrasound videore cording of 90 s was produced, resulting in a file size of 512 MByte. The fi le was compressed to 2, 5 and 10 MByte. The recordings were viewed by a pan el of four experienced observers who were blinded to the compression ratio used. Using a simple seven-point scoring system, the observers rated the qu ality of the clip on 17 items. The maximum compression ratio that was consi dered clinically acceptable was found to be 1:50-1:100. This produced final file sizes of 5-10 MByte, corresponding to a screen size of 320 x 240 pixe ls, running at 15 frames/s. This study expands the possibilities for provid ing tertiary perinatal services to the wider community.