3D ultrasound evaluation of the fetal ear – comparison of an xMatrix probe with a conventional mechanical probe

Purpose: New 3D technologies like xMatrix probes promises superiority to conventional mechanical probes and may allow a more detailed and timesaving prenatal diagnosis. In a comparison study we evaluate the fetal ears. The aims of our study were to compare the following aspects of both techniques: (1) the ultrasound detail resolution, (2) the raw data acquisition time (AT) and (3) the influence of covariates.

Materials and methods: 3D raw data volumes of the fetal ear were collected with the V6 – 2 (V6) and with the xMatrix (X6) probe and were stored after offline customization to a single picture. Two observers scored these images independently. Furthermore, the 3D raw data acquisition time (AT) was recorded. Concordance between observers, maternal age, body mass index (BMI), weeks of gestation and location of the placenta were evaluated.

Results: Data volumes of 103 patients were analyzed. The X6 detected anatomic structures like the scapha (p = 0.0146), fossa triangularis (p = 0.0075) and cymba conchae (p = 0.0025) more often. Mean AT of the X6 was shorter compared to V6 (p < 0.0001). A placenta location in the scanning field increased AT only for the V6 (p < 0.01). Concordance between observers was higher for the X6 in most cases. Detailed structures were less visible at the end of pregnancy for both devices.

Conclusion: The comparison study demonstrated clear advantages of the new xMatrix technology concerning an advanced and fast examination of detailed structures like the fetal ear. Further assessments of the fetal ears with recent 3D technology generate important additional information in prenatal diagnosis.

Fig. 1: 3D images of fetal ears: left V6, right X6