Variability of continuous-wave Doppler flow velocity waveform indices from the umbilical artery.
Using continuous-wave Doppler ultrasound, the reproducibility of umbilical artery blood flow velocity waveforms, recorded by two operators, was evaluated in 20 high-risk antenatal inpatients. Inter-operator variability was not significant for any index. The intra-operator coefficients of variation for resistance index, pulsatility index, and systolic/diastolic ratio were 7 and 7%, 12 and 12%, and 15 and 11%, respectively, for each operator. The intra-class coefficient of reliability, calculated by analysis of variance, indicated that the contribution of inter-patient variability to total variance was four times that of intra-operator variability.
Davies
J A
JA
Institute of Obstetrics and Gynecology, Royal Postgraduate Medical School, University of London, United Kingdom.
Lee
A
A
Spencer
J A
JA
D001783:Blood Flow Velocity; D005260:Female; D006801:Humans; D015588:Observer Variation; D011247:Pregnancy; D014463:Ultrasonography / Q000379:methods*; D014469:Umbilical Arteries / Q000502:physiology*