Diagnostic techniques: Intra-observer, interobserver, interultrasound transducer and intercycle variation in colour Doppler assessment of uterine artery impedance

In this study we assessed the variability of measuring uterineartery pulsatility index by colour Doppler ultrasound usingdifferent ultrasound transducers (abdominal 3 MHz, abdominal5 MHz, endovaginal 5 MHz with and without a full bladder). Wethen assessed the intra-observer coefficient of variation forthe different transducers and interobserver variability fortwo observers using the endovaginal probe. The intercycle variabilityand effects of a full bladder on uterine artery blood flow werealso assessed. The uterine vessels were most easily identifiedusing the endovaginal transducer. The most reproducible resultswere obtained using the endovaginal probe. The coefficientsof variation obtained for the vaginal route were intra-observer4.1%, interobserver 11.8% and intercycle 16.5%. The blood flowindices were significantly different between the endovaginaland both transabdominal 5 and 3 MHz probes (P = 0.0027 and 0.0005respectively). There was no significant effect of a full bladderon pulsatility index. This study suggests that transvaginalcolour Doppler ultrasound is reproducible and the results obtainedfrom clinical use would be reliable.