fetal brain midline structure measurements: cavum septi pellucidi and corpus callosum indices in multiple views at late gestation

Background: the literature lacks studies specifically focusing on cavum septum pellucidum (csp) and corpus callosum (cc) indices in late gestation. in this study, various csp and cc indices, as well as frontal lobe measurements were assessed and the potential correlations among these parameters were evaluated. methods: a cross-sectional study was conducted at imam khomeini hospital complex on 150 fetuses at gestational age of 36 weeks and later. csp length, width, trace length, and area in the axial view; frontal lobe thickness measured from the most anterior and posterior parts of csp in horizontal and vertical directions; cc lengths and thickness; and csp trace length and area in midsagittal view were all obtained via transabdominal ultrasound. spss version 23 was used for data analysis. results: the gestational age, biparietal diameter (bpd), head circumference (hc), and estimated fetal weight (efw) mean±sd were 37.56±1.08 weeks, 90.73±3.20 mm, 326.58±10.59 mm, and 2987.82±333.68 gr, respectively. in the trans-thalamic axial view, medians (iqr) csp length, width, trace length, and axial surface area were 8.92 mm (7.79-9.90), 6.05 mm (5.10-6.71), 2.81 mm (2.51-3.11), and 0.49 mm² (0.39-0.59), respectively. median csp height in the coronal view was 5.85 mm (4.93-7.00). in midsagittal view, mean±sd cc outer-to-outer length, inner-to-inner length, csp trace length, and area were 41.31±4.81 mm, 29.73±4.17 mm, 2.56±0.63 mm, and 0.36±0.19 mm2, respectively. all cc and csp indices correlated significantly with hc (p<0.05). parts in axial and near-field views also showed significant correlations with hc (p= 0.0001). conclusion: this study presented normative data and new indices including fetal cc, csp, and frontal lobe measurements in prenatal sonographic exam of fetuses at gestational age of 36 weeks and later.