1032: Accuracy of three-dimensional automated ultrasound imaging of the fetal brain

Abstract

To evaluate the accuracy of SonoCNS, an automated three-dimensional (3D) ultrasound (US) technique, compared with manual acquisition of five fetal intracranial measurements. A prospective observational study was performed on patients at their anatomical survey between 18’0-22’6 weeks. After informed consent, each patient received an US of the fetal head by a sonographer and a physician (MD) who each obtained manual measurements of the biparietal diameter (BPD), head circumference (HC), transcerebellar diameter (Cer), cisterna magna (CM) and posterior horn of the lateral ventricle (Vp), followed by measurements using SonoCNS. The 3D acquisition was obtained at the transthalamic plane, employing computer-aided recognition, followed by automated alignment and measurements. Both providers performed SonoCNS until all five measurements were obtained in a single sweep, or a maximum of three attempts. The accuracy of SonoCNS was compared to manual measurements using intraclass coefficients (ICC) by provider type, accounting for patient and US characteristics. 143 women were recruited for the study. Median BMI was 24.0 kg/m2 (IQR 22.5-26.8) and median suprapubic subcutaneous thickness (ST) was 1.6cm (IQR 1.3-2.0). Fifteen patients (11%) had at least one prior cesarean section, 17 (11%) had other abdominal surgery, and 78 (55%) had an anterior placenta. Successful acquisition of SonoCNS was achieved in first, second, or third attempts in 70%, 22% and 4% by sonographers and 76%, 16% and 4% by MD. SonoCNS failed in 6 (4%) and 7 (5%) of scans by the sonographers and MD, respectively. The ICC among both providers was high for BPD and HC and lower for Cer, CM and Vp. (Figure 1) Fetal lie, head position, placental location, ST and prior surgical history were not associated with the accuracy of SonoCNS. (Table 1) Automated 3D US imaging of the fetal brain reliably identify and measure BPD and HC, but were less consistent in accurately identifying the Cer, CM or Vp. Further optimization of the automated technology is necessary prior to incorporation into routine US.View Large Image Figure ViewerDownload Hi-res image Download (PPT)