Artifacts in 3D Prenatal Sonography.

PURPOSE: Artifacts may be part of any 3D sonographic examination during pregnancy and can disturb a routine diagnostic procedure, even simulate fetal malformation. The aim of this study was to classify the artifacts in different types according to their appearance. MATERIALS AND METHODS: A total of 2349 healthy fetuses examined during the last five years was included in this study. The observed artifacts have been grouped into 6 different types according to their appearance: 1. fetal movement artifacts, 2. shadow artifacts, 3. amputation artifacts caused by the volume box, 4. defects caused by the improper use of the electronic scalpel, 5. artifacts due to an unfavorable threshold adjustment and 6. artifacts due to superimposed objects. RESULTS: Significant artifacts were found in 119 ultrasound examinations: 39 artifacts were caused by fetal movement, 25 by acoustic shadowing, 19 artifacts occurred due to amputation of objects by the volume box and 15 by the improper use of the electronic scalpel. In 12 cases the threshold adjustment was unfavorable and in 9 cases the artifacts were caused by superimposed objects. CONCLUSION: In 3D ultrasound some artifacts can be avoided by optimizing the size and position of the volume box or by using a different scanning angle. Other artifacts can be minimized using gain and threshold properly and by precise use of the electronic scalpel. In doubtful situations it is recommended to rescan the volume and to use all diagnostic 3D rendering possibilities. Proper recognition of the artifacts can avoid the risk of misdiagnosis.

Prenatal diagnosis of complex phenotype in a 13-week-old fetus with an interstitial multigene deletion 20q13.13.-q13.2 by chromosomal microarray.

We report the first trimester three-dimensional ultrasonographic findings in a 13-week-old fetus with complex phenotype and a de novo 4.7 Mb multigene deletion encompassing chromosome region 20q13.13-q13.2 detected by chromosomal microarray. Fetal sonography detected radial-ray anomalies in the form of bilateral absence of thumbs and the left club hand deformity. The presence of single atrioventricular canal instead of the atrial septal defect typical for Holt-Oram syndrome pointed us to rather suspect the SALL4 related diseases. Central nervous system anomaly in the form of enlarged lateral brain ventricles with choroid plexus shifted backwards was not previously reported as a part of SALL4 related disorders. The pregnancy was terminated at 14 + 3 weeks of pregnancy and the autopsy confirmed ultrasonographic findings. Deleted region included 38 genes, where only SALL4, ADNP and KCNB1 heterozygote pathogenic variants were described to be cause of syndromic forms. Radial ray anomalies are common part of clinical picture of SALL4 related disorders. Despite the lack of prenatally described cases, we hypothesized that maldevelopment of lateral brain ventriculomegaly could be very early sonographic sign of disturbed ADNP expression causing Helsmoortel-Van der Aa syndrome, but in some extent also of KCNB1 related early-onset epileptic encephalopathy. Furthermore, the possible dosage-dependent influence of recessive genes located in this region cannot be also excluded. The use of genome-wide technologies enables the detection of subtle chromosomal imbalances and more precise familial genetic counseling regarding actual and future pregnancies.