Martinez-Ten P, Illescas T, Adiego B, Estevez M, Bermejo C, Wong
AE, Sepulveda W. Non-visualization of choroid plexus of fourth ventricle as first-trimester predictor of posterior fossa anomalies and chromosomal defects. Ultrasound Obstet Gynecol. 2018 Feb;51(2):199-207.
ABSTRACT
OBJECTIVE: To assess non-visualization of the choroid plexus of the fourth
ventricle (CP-4V) as a simple, qualitative and reproducible first-trimester
ultrasound feature of the posterior fossa for the prediction of central nervous
system (CNS) anomalies and chromosomal defects.
METHODS: First-trimester three-dimensional ultrasound datasets of the fetal brain
were obtained prospectively from 65 consecutive normal singletons and
retrospectively from 27 fetuses identified as having an abnormal posterior fossa
on first-trimester ultrasound examination, and randomly combined to form the
final study group. The stored ultrasound volumes were analyzed offline by two
accredited sonologists, who were not aware of the final diagnoses. The CP-4V was
assessed by multiplanar navigation and classified as visible or non-visible in
its normal position depending on whether or not the echogenic structure that
separates the fourth ventricle from the cisterna magna was identified in both
midsagittal and axial planes. Correlation with subsequent second-trimester
ultrasound, fetal magnetic resonance imaging, or postmortem or postnatal findings
was performed to determine the predictive value of the first-trimester findings.
RESULTS: Among the 92 ultrasound datasets analyzed, 73 (79%) were acquired
transabdominally and 19 (21%) transvaginally. The CP-4V was classified as visible
in 64 cases and non-visible in 28 cases, with agreement between the two observers
in both sagittal and axial planes in all but one case. Twelve of the 28 (43%)
fetuses with non-visible CP-4V were subsequently diagnosed as having a CNS
malformation (open spina bifida (n=6), Dandy-Walker malformation (n=2),
Blake's pouch cyst (n=2), cephalocele (n=1) and megacisterna magna (n=1)).
In addition, 20 of these 28 (71%) fetuses had aneuploidy (trisomy 18 (n=10),
triploidy (n=5), trisomy 13 (n=3), Turner syndrome (n=1) or trisomy 21
(n=1)). There was only one false-positive case, in which the CP-4V was
classified as absent in a normal fetus.
CONCLUSIONS: Non-visualization of the CP-4V in the first trimester appears to be
a strong marker of posterior fossa anomalies and chromosomal defects. Qualitative
evaluation of this anatomic structure is simple, feasible and reproducible, and
its routine assessment during the first-trimester scan may facilitate the early
detection of CNS anomalies and associated fetal aneuploidy.
Illescas T, Martínez-Ten P, Bermejo C, Estévez M, Adiego B. Brainstem-vermis and brainstem-tentorium angles: 3D ultrasound study of the intra- and inter-observer agreement. J Matern Fetal Neonatal Med. 2018 Apr;31(8):1073-1077.
ABSTRACT
OBJECTIVE: The brainstem-vermis angle (BVA) and the brainstem-tentorium angle
(BTA) have been proposed to quantify vermian and tentorial alterations associated
to fetal posterior fossa malformations. Our objective is to evaluate the intra-
and inter-observer agreement for the measurement of these angles during the
prenatal ultrasound scan.
METHODS: Fifteen 3D sets from fetuses with posterior fossa pathology were
processed by multiplanar navigation. Four experts in prenatal ultrasound measured
the BVA and the BTA on a mid-sagittal view of the fetal brain, following the
criteria described by Volpe. Observer 1 did also repeated measurements following
both the criteria by Volpe and Ghi. The intraclass correlation coefficient (ICC)
was used to test consistency and absolute agreement for intra- and inter-observer
measurements. The concordance is poor when ICC<0.40 and excellent when
ICC>0.75.
RESULTS: Consistency ICC for measurements between the 4 observers was 0.74
(95% CI: 0.54-0.89) for the BVA and 0.55 (95% CI: 0.29-0.78) for the BTA.
Absolute agreement ICC was 0.67 (BVA) and 0.45 (BTA). The intra-observer study
showed a significantly greater angle with the criteria by Ghi (mean 52.1°,
95% CI: 49.5-54.8) than with the criteria by Volpe (mean 37.4°,
95% CI: 33.1-41.6).
CONCLUSION: A more precise methodology for the measurement of these angles
should be described.
Marín S, Fernández Prada S, Antolín E, Bermejo C, Martínez-Ten P, Mansilla Aparicio E, de la Calle M Rodríguez R Herrero B, Sotillo L, López F, García Santiago FA, Bartha JL. A case of blood chimerism and twin to twin transfusión síndrome in monochorionic dizygotic twins. Clinical Case Reports (en prensa)