Semi-automated adjusted measurement of nuchal translucency: feasibility and reproducibility

Objective The variability of nuchal translucency thickness (NT) measurements in the first trimester appears to be associated in part with caliper placement. Methods for obtaining semi-automated adjusted measurements (SAAMs) can provide several NT values (maximum, minimum, mean and median) automatically within a manually set frame in the zone of interest. This study sought to assess the feasibility and reproducibility of these SAAM-NTs. Methods Three readers, two experts and one less experienced, examined archive images of 160 patients and obtained SAAM-NTs from them, on two separate occasions. The intra-and interobserver reproducibility were assessed by calculating the intraclass correlation coefficients (ICCs) for maximum, mean and median SAAM-NTs, and Bland-Altman plots were constructed. Results SAAM-NTs were technically feasible for all 160 images. The range of ICCs for intraobserver reproducibility was 0.76-0.93 for mean SAAM-NT, 0.76-0.95 for median SAAM-NT and 0.74-0.95 for maximum SAAM-NT. Interobserver ICCs were 0.85, 0.85 and 0.84 for mean SAAM-NT, median SAAM-NT and maximum SAAM-NT, respectively. There were no significant differences for intra-and interobserver reproducibility of median, mean and maximum SAAM-NTs. Conclusions SAAM-NT is feasible with a high level of intra-and interobserver reproducibility. This easy-to-use method has the potential to simplify screening during the first trimester. It should be evaluated further and compared with the manual measurement method. Copyright (C) 2011 ISUOG. Published by John Wiley & Sons, Ltd.