Evaluation of fetal subarachnoid space using transabdominal ultrasonography and normal values during pregnancy

Abstract

Objectives To determine the feasibility of evaluating the subarachnoid space by measuring two novel sonographic parameters in axial section using transabdominal ultrasound, in addition to the parameters previously defined in coronal section, and to construct a normal range for the subarachnoid space width in singleton healthy fetuses.MethodsHealthy pregnant women between 20 and 29 weeks were scanned using transabdominal ultrasound. Four variables were measured for the evaluation of subarachnoid space width; sinocortical width and anterior craniocortical width in coronal plane, and lateral and posterior craniocortical width in axial plane.ResultThe data of 154 patients were recorded. SCW could be measured in 87.6 % (135) of fetuses, while the same figure was 77.9 % (120), 96.1 % (151) and 98.1 % (148) for anterior, lateral and posterolateral CCW, respectively. The SCW and anterior CCW did not display a significant correlation with gestational age and head circumference. The mean of SCW was 1.55 ± 0.41 mm with a range of 0.85–3.87 mm. The mean anterior CCW was 1.63 ± 0.39 mm with a range of 0.85–2.82 mm. A linear regression line was plotted between gestational age and lateral CCW (r = 0.707; p < 0.0001) and posterolateral CCW (r = 0.437; p < 0.0001), and nomograms for these parameters are constructed.ConclusionThis study presents a novel approach for the in utero evaluation of the subarachnoid space with two measurements in axial plane using transabdominal ultrasound. The nomograms will be helpful when there is a suspicion of subarachnoid space dilatation during routine cranial scan.

Does diabetes mellitus affect the development of fetal brain structures and spaces including corpus callosum, subarachnoid space, insula, and parieto‐occipital fissure?

“…This measurement was conducted within the transventricular axial plane, oriented perpendicular to the midline, and precisely situated at the level of the posterior infolding boundary of the Sylvian fissure (Figure 1C). The PCC width was measured at the anterior margin of the lambdoid suture in the transventricular axial plane 17 (Figure 1D), with a standard transventricular axial plane of the fetal head, which is commonly utilized for measuring the biparietal diameter and OFD. This imaging plane enables the recognition of anatomical structures including the CSP, atrium, and posterior horns of the lateral ventricles with choroid plexuses 18 .…”