EP05.08: Antenatal visualisation of the caudo‐thalamic groove at expert fetal neurosonography

To describe the sonographic features of the caudo-thalamic (CT) groove in the third trimester of pregnancy in normal fetuses and in a case series with destructive lesions of the groove. Observational study conducted at two referral Fetal Medicine units. A non-consecutive cohort of normal fetuses was prospectively recruited and underwent 3D ultrasound of the fetal brain at 28-32 weeks. At offline analysis the ultrasound volumes were adjusted in the multiplanar mode according to a standardised methodology, until the CT groove was visible on the parasagittal plane. To evaluate the interobserver agreement, two operators were independently asked to indicate if the CT groove was visible unilaterally or bilaterally on each volume. The digital archives of the two Centres were also retrospectively searched to retrieve cases with abnormal findings at the level of the CT groove at antenatal brain ultrasound which were postnatally confirmed. 180 cases were included. At offline analysis of the 3D US volumes the CT groove was identified on the parasagittal plane by both operators at least unilaterally in 176 cases (97.8%) and bilaterally in 174 cases (96.6%). The K-coefficient for the agreement between the two independent operators in recognising the CT groove was 0.89 and 0.83 on one and both hemispheres respectively. At the retrospective search of our archives 5 cases with abnormal appearance of the groove at antenatal brain ultrasound (2 hemorrhage and 3 cyst) were found. Our study has demonstrated that the caudo-thalamic groove is consistently seen among normal fetuses at third trimester submitted to multiplanar neurosonography and that abnormal findings at this level may be antenatally detected. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.