Semi-Automatic Identification of the Fetal Profile and Nasal Bone Measurement at the Time of the Routine Mid-Trimester Ultrasound Scan

Purpose: This study was designed to compare nasal bone length (NBL) measurements using a manual multiplanar mode with those made using a newer semi-automatic technique (Volume NT (TM)) acquired by an experienced operator as well as measurements done by two independent observers with different levels of ultrasound experience (conventional 2D vs. Volume NT (TM)). Materials and Methods: Ultrasound examination was performed prospectively on 81 pregnant women with a singleton pregnancy at the time of their routine mid-trimester ultrasound scan. Results: The correct mid-sagittal plane of the fetal profile was successfully obtained using the semiautomatic technique in 53 of 81 cases. Conclusion: NBL measurements using conventional two-dimensional techniques showed significantly higher inter-observer variability than the semi-automatic program. Our study shows the feasibility of using a semi-automatic technique, especially for less experienced operators. Measurements obtained with the semi-automatic technique produced much less variable results around a mean than those obtained with conventional two-dimensional ultrasound.