Three‐dimensional ultrasound imaging and measurement of nasal bone length, prenasal thickness and frontomaxillary facial angle in normal second‐ and third‐trimester fetuses

• Published in: Ultrasound in obstetrics & gynecology 2012-06, Vol.39 (6), p.636-641
• Main Authors: Vos, F. I., De Jong‐Pleij, E. A. P., Ribbert, L. S. M., Tromp, E., Bilardo, C. M.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Bone; Chromosome aberrations; Cross-Sectional Studies; Down syndrome; Down Syndrome - diagnostic imaging; Down Syndrome - embryology; Face - diagnostic imaging; Face - embryology; Face - physiology; Feasibility Studies; Female; frontomaxillary facial angle; Gestational Age; Gynecology. Andrology. Obstetrics; Humans; Imaging, Three-Dimensional; Medical genetics; Medical sciences; Nasal Bone - diagnostic imaging; Nasal Bone - embryology; Nasal Bone - physiology; nasal bone length; Observer Variation; Pregnancy; Pregnancy Trimester, Second; Pregnancy Trimester, Third; prenasal thickness; Reference Values; three‐dimensional ultrasound; Ultrasonography, Prenatal - methods; ultrasound marker
• ISSN: 0960-7692; 1469-0705
• DOI: 10.1002/uog.10058

Objectives To assess the feasibility of nasal bone length (NBL), prenasal thickness (PT) and frontomaxillary facial (FMF) angle measurements performed on the same three‐dimensional (3D) multiplanar‐corrected profile view in healthy second‐ and third‐trimester fetuses, to create reference ranges and to review published measurement techniques. Methods 3D volumes of 219 healthy second‐ and third‐trimester fetuses were retrospectively analyzed. The quality of images and measurability of the markers were assessed with 5‐point and 3‐point scoring systems, respectively. Measurements of NBL (with care to exclude the frontal bone), PT and FMF were obtained in the exact mid‐sagittal plane. Reference ranges were constructed based on measurements from images with high‐quality (4 or 5 points) and high measurability (2 or 3 points) scores and compared with those in the most relevant published literature. Results A high‐quality score was assigned to 111 images. Among these, a high measurability score was significantly more often achieved for NBL (98.2%) and PT (97.3%) than for the FMF angle (26.1%) (P < 0.001). Both NBL (NBL = − 6.927 + (0.83 × GA) − (0.01 × GA2)) and PT (PT = (0.212 × GA) − 0.873) (where GA = gestational age) showed growth with gestation, with less pronounced growth for NBL after 28 weeks. Our reference range for the NBL showed a systematically smaller length than those in other two‐dimensional (2D) ultrasound‐based publications. The FMF angle measurements that we obtained did not show a significant change with GA. Conclusions NBL and PT are easily measured using 3D ultrasound whereas FMF angle measurement is more challenging. When it is measured in the exact mid‐sagittal plane and care is taken to exclude the frontal bone, measurements of the NBL are systematically smaller than those in previous 2D ultrasound‐based publications. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd.