Power Doppler imaging of the fetal upper aerodigestive tract using a 4-point standardized evaluation: Preliminary report

Objective. Our investigation of fetal swallowing has identified potential limitations in the use of color Doppler imaging for detection of amniotic fluid flow and discrimination of respiratory from ingestive activity. The objective of this study was to evaluate an alternative imaging modality, power Doppler sonography, as a technique to enhance detection of amniotic fluid flow in the upper aerodigestive tract. Methods. We applied a standardized 4-axis sonographic examination of upper aerodigestive structures and used power Doppler imaging to document amniotic fluid flow. Normal aerodigestive activities from 62 healthy control subjects were compared with 4 abnormal cases. Results. Our longitudinal experience with 66 subjects showed that a directed evaluation of the fetal upper aerodigestive tract with power Doppler imaging provided a systematic approach for studying the physiologic development of this region in both healthy and at-risk fetuses. Conclusions. A standardized 4-axis examination with power Doppler imaging is a useful adjunct in addressing ingestive and respiratory functions in the developing fetus.