Assessment of fetal midbrain and hindbrain in mid‐sagittal cranial plane by three‐dimensional multiplanar sonography. Part 1: comparison of new and established nomograms

ABSTRACT Objective To construct nomograms for fetal midbrain (MB) and hindbrain (HB) dimensions, assessed in the mid‐sagittal cranial plane by three‐dimensional multiplanar sonographic reconstruction (3D‐MPR). Methods This was a prospective cross‐sectional study of 334 healthy fetuses in low‐risk singleton pregnancies between 16 and 35 gestational weeks. All sonographic volumes were obtained by sagittal acquisition. The following MB and HB parameters were evaluated in the mid‐sagittal cranial plane using 3D‐MPR: MB parameters tectal length (TL) and anteroposterior midbrain diameter (APMD), and HB parameters anteroposterior pons diameter (APPD), superoinferior vermian diameter (SIVD), anteroposterior vermian diameter (APVD) and anteroposterior diameter of the fourth ventricle (APDFV). The measurements were presented as growth charts according to gestational age. Results MB and HB biometry were best assessed between 19 and 29 weeks. During this period, adequate visualization was achieved for successful measurement of TL in 90.9% of cases, APMD in 86.6%, APPD in 73.7%, SIVD in 74.2%, APVD in 71% and APDFV in 71%. There was a linear growth pattern, with Pearson correlation coefficients of 0.79 for TL, 0.88 for APMD, 0.91 for APPD, 0.95 for SIVD, 0.88 for APVD and 0.88 for APDFV (P