Feasibility of detection of the 3-vessel and trachea view using 3-dimensional sonographic volumes

Congenital Aortic Vascular Ring: In-Utero Sonographic Assessment of Tracheal Patency and Postnatal Outcome

OBJECTIVE

 Congenital aortic vascular ring may present after birth with variable degrees of respiratory distress due to tracheal compression. The aim of this study was to prospectively evaluate in utero tracheal patency in correlation with postnatal outcome.

METHODS

 During an eight-year period, fetuses with aortic arch abnormality encircling the trachea and forming a complete ring were recruited for the study. Tracheal patency was classified as: no compression, partial compression, or complete compression. Postnatal MRI/CTangio studies were performed and outcome data was retrospectively analyzed from the medical records.

RESULTS

 Among the 46 fetuses recruited to the study, 38 had right aortic arch (RAA), and 8 presented with double aortic arch (DAA). In the RAA group 35 (92.1 %) of the fetuses presented no compression and 34 (97.1 %) of them were asymptomatic in the long-term follow-up. Three fetuses (7.9 %) in this group presented in utero compression: one was terminated at 16 weeks of gestation due to associated ominous findings, and the other two had mild respiratory symptoms around 12 months of age and underwent surgery with a good outcome. In the DAA group, all fetuses presented in utero with tracheal compression. Seven showed partial and one complete compression. Among the seven with partial compression, six were symptomatic and underwent surgery. The case with severe airway occlusion had emergency tube insertion in the delivery room and underwent surgery at 7 days but died from severe respiratory complications.

CONCLUSION

 This is the first study to evaluate in utero tracheal patency in cases with vascular ring. It allows better prenatal and postnatal workup and follow-up including potentially life-threatening respiratory failure.

Screening the second-trimester fetal heart in women with an increased body mass index using three-dimensional volume sweep

PURPOSE

To determine the percentage of fetal cardiac anatomy as detailed in the International Society of Ultrasound in Obstetrics and Gynecology Practice Guidelines on sonographic screening examination of the fetal heart, which can be visualised in women with a body mass index (BMI) >30 kg/m² using three-dimensional (3D) volume sweeps.

METHODS

3D volumes of the fetal heart were taken prospectively in 40 fetuses during routine second-trimester fetal anatomy scan. Scans and 3D volume sweeps were performed by two experienced sonographers and two experienced raters interpreted the 3D data. 3D volume acquisitions and post-processing analysis were performed according to the techniques described by Weissmann-Brenner et al.

RESULTS

The two raters were able to detect an average of 12.9 and 14.1 of the 16 parameters in the 40 patients. Agreement between raters for the 16 parameters had an average of 80%. Five parameters (stomach, situs, heart occupies a third of thoracic area, majority of heart in the left chest and cardiac axis) were detected by both raters on all patients. The range of agreement was between 40% and 100%. The three-vessel view and bifurcation had agreement <60%.

CONCLUSION

Consistent identification of all views of the fetal heart was not achieved using the simple method described in women with a BMI > 30 kg/m².

Is the "I-Sign" in the 3-Vessel and Trachea View a Valid Tool for Prenatal Diagnosis of D-Transposition of the Great Arteries?

Prenatal diagnosis of D-transposition of the great arteries remains less frequent compared to other major congenital heart defects. In this study, we examined how often the 3-vessel and trachea view was abnormal in a large series of prenatally diagnosed cases of D-transposition of the great arteries. We found that an abnormal 3-vessel and trachea view in the shape of an "I" ("I-sign"), which represents an anteriorly displaced aorta, was present in all fetuses with D-transposition of the great arteries when a 3-vessel and trachea view was successfully obtained. Therefore we believe that the 3-vessel and trachea view can be used to reliably detect D-transposition of the great arteries during prenatal sonography.