Literature DB >> 20127748

Learning curve in measurement of fetal frontomaxillary facial angle at 11-13 weeks of gestation.

X Yang1, M Chen, H F Wang, T Y Leung, M Borenstein, K Nicolaides, D S Sahota, T K Lau.   

Abstract

OBJECTIVE: To determine the number of ultrasound examinations required to train sonographers to accurately measure the fetal frontomaxillary facial (FMF) angle at 11-13 weeks of gestation.
METHODS: Eight sonographers accredited for nuchal translucency thickness (NT) measurement (and with different levels of experience) were trained to measure the fetal FMF angle using specially acquired three-dimensional (3D) volumes. Training was provided in cycles, and each cycle consisted of a training period on 20 randomly selected cases followed by an examination using 10 randomly selected cases. During training, the sonographer was informed of the true FMF angle value after each FMF angle measurement on a case-by-case basis. During examination, the difference between the measured and the true values of the FMF angle (i.e. the delta angle) was calculated. A measurement was considered accurate if the delta angle was less than 5 degrees . The sonographer was considered to be competent and the training finished if all 10 examination cases satisfied this criterion. Otherwise, the sonographer would undergo further cycles of training-examination, until he/she became competent.
RESULTS: The number of training cases required for a sonographer to become competent was 40 for two sonographers, 60 for one, 80 for one, 100 for two, 120 for one and 140 for one, with a median of 90. The median number of failed cases reduced from 2.5 (out of 10) at the first cycle to 0 by the 7(th) cycle. As training cycles increased, the mean angle deviation and measurement time required both reduced significantly. The average delta angle of the passing examination cycle was 2.06 +/- 1.40 degrees . The number of training cases required to become competent in FMF angle measurement was 40 for the two most experienced trainees and 80, 120 and 140 for the three least experienced ones.
CONCLUSIONS: We have demonstrated that competence in FMF angle measurement was achieved after a median number of 90 cases, with a range of up to 140. The number required was substantially lower, at 40 cases, among those with extensive experience of NT measurement. Copyright 2010 ISUOG. Published by John Wiley & Sons, Ltd.

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Year:  2010        PMID: 20127748     DOI: 10.1002/uog.7574

Source DB:  PubMed          Journal:  Ultrasound Obstet Gynecol        ISSN: 0960-7692            Impact factor:   7.299


  2 in total

1.  The Effect of Ethnicity on 2D and 3D Frontomaxillary Facial Angle Measurement in the First Trimester.

Authors:  Jennifer Alphonse; Jennifer Cox; Jill Clarke; Philip Schluter; Andrew McLennan
Journal:  Obstet Gynecol Int       Date:  2013-10-28

2.  Frontomaxillary facial angle measurement in screening for trisomy 18 at 11 + 0 to 13 + 6 weeks of pregnancy: a double-centre study.

Authors:  Bartosz Czuba; Wojciech Cnota; Agata Wloch; Piotr Wegrzyn; Krzysztof Sodowski; Miroslaw Wielgos; Dariusz Borowski
Journal:  Biomed Res Int       Date:  2013-10-01       Impact factor: 3.411

  2 in total

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