Rutherford S E, Smith C V, Phelan J P, Kawakami K, Ahn M O
Department of Obstetrics and Gynecology, University of Southern California School of Medicine, Los Angeles.
J Reprod Med. 1987 Aug;32(8):587-9.
While the use of the four-quadrant technique, or the amniotic fluid index (AFI), for amniotic fluid volume assessment has been shown to correlate with perinatal outcome, one concern among clinicians is the reliability of a single AFI measurement. The purpose of this investigation was to ascertain the margin of error using this technique among 23 term and postterm women. The AFI was obtained using linear array real-time B-scan ultrasound to measure the vertical diameter of the largest amniotic fluid pocket in each of the four quadrants. The sum of these measurements was expressed as the AFI. Eight women underwent ten consecutive AFI measurements by the same sonographer to determine intraobserver variation. Interobserver variation between five sonographers was measured by assessing the AFI in 15 additional patients. With the amniotic fluid volume in the low or normal range, our results demonstrated the intraobserver and interobserver variations in AFI to average 1.0 and 2.0 cm, respectively. With an above-normal amniotic fluid volume, a 2.5- to 3-fold greater variation was observed. A relatively small margin of error appears to exist between observers using the four-quadrant technique to assess amniotic fluid volume.
虽然已证明使用四象限技术或羊水指数（AFI）评估羊水量与围产期结局相关，但临床医生担心的一个问题是单次AFI测量的可靠性。本研究的目的是确定在23名足月和过期妊娠妇女中使用该技术的误差范围。使用线性阵列实时B超测量四个象限中每个象限最大羊水池的垂直直径来获得AFI。这些测量值的总和表示为AFI。8名妇女由同一名超声检查人员连续进行10次AFI测量，以确定观察者内变异。通过评估另外15名患者的AFI来测量5名超声检查人员之间的观察者间变异。当羊水量处于低或正常范围时，我们的结果表明AFI的观察者内和观察者间变异平均分别为1.0 cm和2.0 cm。当羊水量高于正常范围时，观察到的变异大2.5至3倍。使用四象限技术评估羊水量时，观察者之间似乎存在相对较小的误差范围。
