Armando Pintucci

Sonographic diagnosis of fetal cerebral ventriculomegaly: An update

Dilatation of the fetal cerebral ventricles (ventriculomegaly) is a generic sonographic sign that is common to several pathological entities carrying different prognoses. The main causes of fetal ventriculomegaly are aqueductal stenosis, Chiari II malformation, Dandy–Walker complex, and agenesis of the corpus callosum. Ventriculomegaly is easily recognized by ultrasound by measuring the atrial width. This simple measure allows the recognition of mild forms of ventricular dilatation and is used in screening for ventriculomegaly. However, although the diagnosis of ventriculomegaly is easy, the prenatal identification of the cause of ventricular dilatation is a more difficult task. For this purpose the evaluation of the posterior fossa in association with the visualization of the corpus callosum is useful. Research into the causes of ventriculomegaly is clinically useful, since the prognosis mainly depends on the etiology and on the presence of associated abnormalities. In this article the role of prenatal sonography in determining the cause of the ventriculomegaly is reviewed, as well as the prognostic value of the prenatal sonographic findings.

Comparison of six sonographic signs in the prenatal diagnosis of spina bifida.

Abstract Aims: To compare the diagnostic accuracy of sonographic signs that may be looked for in fetuses with spina bifida. Methods: Forty-nine fetuses affected by spina bifida were enrolled, at a gestational age of 18–28 weeks. The following sonographic signs were looked for: “lemon” sign, small cerebellum, effaced cisterna magna, small posterior fossa, ventriculomegaly and direct visualization of a spinal defect. Results: The “lemon” sign was present in 53%, a small cerebellum in 96%, an effaced cisterna magna in 93%, a small posterior fossa in 96%. Ventriculomegaly was present in 40/49 (81%) cases and was severe in 20 fetuses and borderline in the remaining 20. The spinal defect was missed in one fetus presenting the cerebellar and posterior fossa signs. In two fetusus, the myelomeningocele was present without cranial signs of Chiari II malformation and in both cases the defect was covered by intact skin. Conclusions: Our results confirm the usefulness of evaluation of the posterior fossa in the diagnosis of spina bifida, particularly in cases of small spinal defects that may be missed at ultrasound. Conversely, myelomeningocele covered by intact skin was not associated with the cranial signs of Chiari II malformation.

The midsagittal view of the fetal brain: a useful landmark in recognizing the cause of fetal cerebral ventriculomegaly.

Abstract Aim: To evaluate the positive predictive value of the midsagittal view of the fetal brain in recognizing the cause of ventriculomegaly diagnosed with traditional axial scan. Methods: Fifty-eight pregnant women, referred to our Center following a generic diagnosis of ventriculomegaly have been evaluated: 38 had marked and 20 had borderline ventriculomegaly. The fetal brain was scanned by the midsagittal view using a transabdominal probe in fetuses in breech presentation or transverse lie and a transvaginal probe in fetuses in cephalic presentation. The possible cause of ventriculomegaly was postulated by combining the findings of the corpus callosum/cavum septi pellucidi complex with those of the posterior fossa. The prenatal diagnoses were compared with the anatomical specimens of aborted fetuses or with postnatal neuroimaging. Results: The prenatal diagnoses were confirmed in 54/58 cases (PPV 93.1%). In the marked ventriculomegaly group, one case of partial agenesis of the corpus callosum was mistaken for a complete agenesis. In the group of borderline ventriculomegaly, two cases of partial agenesis of the corpus callosum were confused with a complete agenesis, while one case of suspected isolated ventriculomegaly was diagnosed after birth as partial agenesis of the corpus callosum. Conclusions: The sagittal scan of the fetal brain is a useful source of information and allows the contemporary view of both corpus callosum and posterior fossa, where various typical sonographic findings are present in ventriculomegaly.

Cavum veli interpositi cyst: prenatal diagnosis and postnatal outcome

The cavum veli interpositi (CVI) is a space within the double‐layered tela choroidea of the third ventricle. Occasionally, this space is fluid‐filled and sonographically visible as an interhemispheric anechoic cyst. Because of its rarity, the incidence of CVI cyst is undetermined and the outcome of affected individuals has been found to be variable. The aim of this study was to report our experience of the sonographic findings and outcome of fetuses affected by CVI cysts.

Premature rupture of membranes at term in low risk women: how long should we wait in the “latent phase”?

Abstract Aim: How long the waiting time may be for the onset of spontaneous labor after prelabor rupture of fetal membranes at term (tPROM) remains controversial. Methods: The study is an observational cohort study of 6032 women. All obstetric patients with no obstetric risk factors, other than tPROM, were included. The analysis focused on the onset of labor (spontaneous vs. induction), maternal morbidity [cesarean section (CS) and chorioamnionitis] and neonatal morbidity (suspected infection) related to a policy of waiting for the onset of spontaneous labor within 48 h of tPROM. Results: tPROM was experienced by 1439 women. A careful clinical management shows a very low rate of clinical chorioamnionitis (2.3%) and neonatal infection rate (2.8%), even after 24 h from tPROM. The overall incidence of CS was 4.5%. Furthermore, a policy of waiting for the onset of spontaneous labor within 48 h of tPROM is associated with a low rate of CS, less than induced labor (OR=1.76; 95% confidence interval 1.03–3.02; P<0.004). Conclusions: Fetal and/or maternal morbidity in tPROM women may not increase if there is a strict analysis of maternal and or fetal risk factors added to a careful clinical management. Moreover, it may be useful to wait for spontaneous labor in order to enhance the patient’s chance of vaginal delivery.

OP03.05: Prenatal diagnosis and outcome of cavum veli interpositi cysts

Objectives: To evaluate the feasibility and the processing time using off-line analysis of 3D brain volumes to perform basic as well as detailed, targeted, fetal neurosonogram. Study design: Three dimensional fetal brain volumes were obtained in 20 consecutive healthy fetuses that underwent routine anatomical survey at 20 to 23 post menstrual weeks. Grey scale and power Doppler volumes of the fetal brain were acquired in the axial, coronal and the sagittal planes using trans-abdominal and transvaginal approaches, respectively. Off-line analysis of each volume was performed by two of the authors in a blinded fashion. Initially, a list containing the basic structures, as defined by ISUOG and AIUM guidelines, complete with intra-cranial biometrical measurements was attempted. Subsequently, we attempted to identify a list of CNS structures recommended by ISUOG guidelines for fetal neurosonogram. Additional structures that were selected by the authors were also sought (see * in table). The feasibility of obtaining diagnostic quality images was evaluated. The processing times of volume acquisition as well as the off-line analysis were recorded. Results: Volume acquisition time was 3–6 sec/volume and a mean processing time of 9.5 and 11 minutes to complete both the ‘basic’ and the ‘detailed’ neurosonogram was recorded by the two examiners, respectively. The feasibility of obtaining diagnostic quality images of the different structures is displayed in the table. Conclusions: Off-line analysis of fetal 3D brain volumes at 20–23 weeks of gestation can identify all the structures necessary to complete a detailed fetal neurosonogram. This approach may provide several potential advantages such as a short processing time, increased safety due to shorter dwell time, increased patient through-put, and the ability to obtain off-site expert consultation if necessary.

OP13.04: Accuracy of six sonographic signs in the prenatal dignosis of spina bifida

(FAPD/BPD, FLLD/BPD) and the perimeter and area for the HC (FPer/HC, FA/HC). The best curve to fit the relationships of the different variables with gestational age was identified and the changes in the absolute fontanelle size and of its relationship with the fetal head during gestation were analyzed. Results: A linear regression model fitted FLLD, FA, and all ratios, while a quadratic regression model fitted FAPD and FPer. The absolute size of the fontanelle significantly increased during the first half of pregnancy, until 26 weeks of gestation, to plateau or decrease thereafter. However, all ratios showed a significant negative correlation with advancing gestational age. Conclusions: This study suggests that the rapid growth of the fetal head, determined by the expansion of the brain, occurs faster than the ossification of the cranial bones and the anterior fontanelle. This determines an increase in the absolute size of the fontanelle despite the fact that its size relative to the whole volume of the fetal head is rapidly decreasing. It could be suggested that it is the fetal head that grows around the anterior fontanelle rather than the latter reducing in size during gestation. These data may be of help in understanding the mechanism behind an abnormal fontanelle development (delayed ossification or premature closure).