Is 3-dimensional volume sonography an effective alternative method to the standard 2-dimensional technique of...

To determine whether 3-dimensional (3D) volume scanning is an effective alternative method of measuring nuchal translucency in first-trimester fetuses compared with the standard 2-dimensional (2D) technique, and to report a standardized method of evaluation.

We measured the nuchal translucency of 29 fetuses between 11.4 and 13.9 weeks of age using the standard 2D sonographic technique with the fetus in a sagittal view. We then rescanned the fetus in a coronal orientation and obtained a 3D volume of the fetal neck area from crown to rump using a consistent technique. The sagittal orientation was reconstructed, and the width of the nuchal translucency was measured electronically using the reconstructed midsagittal view. The measurements using a conventional 2D sagittal view were then compared with the 3D reconstructed sagittal view. The nuchal translucency was adequately measured in all fetuses in which the 3D assessment was attempted.

The nuchal translucencies of 29 consecutive fetuses were measured using both 2D and 3D multiplanar reconstruction of the fetal neck. The mean +/- standard deviation for the standard 2D assessment of the nuchal translucency was 1.7 +/- 1.4 mm. Using 3D reconstruction of the Z plane, the measurement was 1.8 +/- 1.6 mm. This was not a statistically significant difference (P = 0.4). There was a very high correlation between the two techniques (r = 0.984, P < 0.001).

There is an excellent correlation between the measurements of the nuchal translucency using standard 2D scanning and those obtained from 3D multiplanar reconstruction of the Z plane. Using a consistent technique, the nuchal translucency can be accurately and reliably measured with a 3D rendering. This technique is potentially useful in fetuses that are not in an optimal position for standard 2D nuchal translucency measurement.