First-Trimester Visualization of the Fourth Ventricle in Fetuses With and Without Spina Bifida

Prospective Study of Intracranial Translucency and the Posterior Brain in Normal Fetuses at the 11‐ to 13‐Week Scan

“…In addition, whether “small intracranial translucency” (measurement <5th percentile) when used as an additional marker would improve the screening efficacy of “absent intracranial translucency” for open spina bifida is uncertain. So far, in several cases of open spina bifida reported in the literature, in which intracranial translucency was determined to be present and a measurement was feasible, the intracranial translucency measurements were within the normal range 3 , 14 …”

“…Chaoui et al 1 , 2 first described intracranial translucency as a useful marker in the detection of open spina bifida at the 11‐ to 13‐week scan, using the midsagittal image of the fetal head and face obtained for nuchal translucency measurement. Subsequently, it has been shown in 2 retrospective studies that normal intracranial translucency had high specificity (98%–99%) for exclusion of open spina bifida, but the sensitivity was only 45% to 50% 3 , 4 . In a retrospective review of images obtained for nuchal translucency measurement, Mangione et al 5 reported that intracranial translucency could be identified in only 52% of normal fetuses, but the visualization rate increased to 85% after specific training of the sonographers.…”

Diagnostic accuracy of intracranial translucency in detecting spina bifida: a systematic review and meta-analysis

“…Sixteen studies evaluating the sonographic detection of SB in the first trimester in singleton gestations were assessed for the eligibility . Seven of them were excluded . Two were excluded because IT was not evaluated; two were excluded because they were case series; Liu et al .…”

“…Seven of them were excluded . Two were excluded because IT was not evaluated; two were excluded because they were case series; Liu et al . was excluded because they used women without IT measurement as controls, while two were excluded due to lack of data allowing construction of a 2 × 2 table .…”

Intracranial translucency assessment at first trimester nuchal translucency ultrasound

“…reported a sensitivity and specificity of 100% for absence of IT for detection of OSB. However, since then, reports of IT as a single marker for OSB detection have been less promising with sensitivities ranging from 28.8% to 50%, although specificities remain more consistent ranging from 98% to 99% . In addition, there have been reports of cases of OSB with normal ICT .…”