Routine Sonographic Measurement of the Near‐Field Lateral Ventricle During Second‐Trimester Morphologic Scans

Objectives The purpose of this study was to determine whether measurement of the near‐field lateral ventricular diameter can be reliably obtained within a practical time frame during second‐trimester obstetric scans by angling the fetal head approximately 30° away from the horizontal image axis such that the posterior aspect of the fetal head lies closer to the transducer. Methods Fifty consecutive singleton pregnancies presenting for a routine‐second trimester scan were recruited for this study. The far‐field lateral ventricular diameter was measured, followed by the near‐field lateral ventricular diameter using the proposed technique. The measurements were repeated by a second operator who was blinded to the first measurement. Both operators recorded the measurements taken and scored the level of visibility of the near‐field lateral ventricle. The difference between the two operators' measurements was compared by a κ analysis. Results The near‐field lateral ventricle was visualized in 49 of 50 cases (98%). There was no statistically significant difference in the measurement of the near‐field lateral ventricular diameter by the two operators ( P = .34). There was, however, a statistically significant difference in the time it took each operator to obtain the near‐field measurement after the far‐field measurement ( P = .01). Conclusions Manipulating the transducer to position the falx of the fetal head approximately 30° away from the horizontal image axis allows the near‐field lateral ventricle to be routinely visualized and measured with a high degree of interoperator agreement and within a practical time frame once the operator is experienced in performing the technique.