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Intra‐ and interoperator reliability of manual and semi‐automated measurements of intracranial translucency
Author(s) -
Karl K.,
Kagan K. O.,
Chaoui R.
Publication year - 2012
Publication title -
ultrasound in obstetrics and gynecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.202
H-Index - 141
eISSN - 1469-0705
pISSN - 0960-7692
DOI - 10.1002/uog.10137
Subject(s) - medicine , repeatability , gold standard (test) , nuclear medicine , reproducibility , nuchal translucency , interquartile range , calipers , operator (biology) , biomedical engineering , surgery , radiology , statistics , mathematics , first trimester , gestation , pregnancy , geometry , repressor , chemistry , biology , biochemistry , genetics , gene , transcription factor
Objectives To assess the reproducibility of fetal intracranial translucency (IT) measurements performed manually or with SonoNT ® , a semi‐automated caliper placement technique recently introduced for nuchal translucency thickness (NT) measurement. Methods This was a retrospective study using 116 stored images of the head (mid‐sagittal plane) from normal fetuses in dorsoposterior position at 11–13 weeks. Two experienced operators each measured the IT separately, twice manually and twice using the semi‐automated software. Intraoperator and interoperator repeatability were assessed. The mean of the two manual measurements of the more experienced Operator 2 was considered as the ‘gold standard’. Results Seven cases were excluded as the IT could not be recognized by the semi‐automated software. In the remaining 109 cases, the interquartile range of the mean IT measurement was 1.9–2.4 mm for Operator 1 and 1.8–2.3 mm for Operator 2 for both the manual and the semi‐automated IT measurements. The intraoperator SD for manual measurements was 0.091 mm for Operator 1 and 0.088 mm for Operator 2, and for semi‐automated measurements it was 0.054 mm for Operator 1 and 0.067 mm for Operator 2. Concerning interoperator bias of the manual measurements, the mean difference between Operator 1 and Operator 2 was − 0.09 (95% CI, − 0.11 to − 0.07) mm. With respect to the gold standard, the mean bias of the semi‐automated measurements was 0.01 (95% CI − 0.01 to 0.03) mm for Operator 1 and − 0.09 (95% CI − 0.11 to − 0.07) mm for Operator 2, indicating good agreement. Conclusions Manual IT measurements are reproducible. In addition, IT can be assessed reliably using the semi‐automated NT algorithm, leading to standardization of the IT assessment process. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.