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Concept: 3D ultrasound

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In the third trimester of pregnancy, the human fetus has the capacity to process perceptual information [1-3]. With advances in 4D ultrasound technology, detailed assessment of fetal behavior [4] is now possible. Furthermore, modeling of intrauterine conditions has indicated a substantially greater luminance within the uterus than previously thought [5]. Consequently, light conveying perceptual content could be projected through the uterine wall and perceived by the fetus, dependent on how light interfaces with maternal tissue. We do know that human infants at birth show a preference to engage with a top-heavy, face-like stimulus when contrasted with all other forms of stimuli [6, 7]. However, the viability of performing such an experiment based on visual stimuli projected through the uterine wall with fetal participants is not currently known. We examined fetal head turns to visually presented upright and inverted face-like stimuli. Here we show that the fetus in the third trimester of pregnancy is more likely to engage with upright configural stimuli when contrasted to inverted visual stimuli, in a manner similar to results with newborn participants. The current study suggests that postnatal experience is not required for this preference. In addition, we describe a new method whereby it is possible to deliver specific visual stimuli to the fetus. This new technique provides an important new pathway for the assessment of prenatal visual perceptual capacities.

Concepts: Pregnancy, Childbirth, Infant, Embryo, Fetus, Uterus, Abortion, 3D ultrasound

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With advances of research on fetal behavioural development, the question of whether we can identify fetal facial expressions and determine their developmental progression, takes on greater importance. In this study we investigate longitudinally the increasing complexity of combinations of facial movements from 24 to 36 weeks gestation in a sample of healthy fetuses using frame-by-frame coding of 4-D ultrasound scans. The primary aim was to examine whether these complex facial movements coalesce into a recognisable facial expression of pain/distress. METHODOLOGYFINDINGS: Fifteen fetuses (8 girls, 7 boys) were observed four times in the second and third trimester of pregnancy. Fetuses showed significant progress towards more complex facial expressions as gestational age increased. Statistical analysis of the facial movements making up a specific facial configuration namely “pain/distress” also demonstrates that this facial expression becomes significantly more complete as the fetus matures. CONCLUSIONSSIGNIFICANCE: The study shows that one can determine the normal progression of fetal facial movements. Furthermore, our results suggest that healthy fetuses progress towards an increasingly complete pain/distress expression as they mature. We argue that this is an adaptive process which is beneficial to the fetus postnatally and has the potential to identify normal versus abnormal developmental pathways.

Concepts: Pregnancy, Embryo, Fetus, Uterus, Developmental biology, Abortion, 3D ultrasound, Gestational age

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The aim of this study was to predict the timing of delivery within seven days in singleton pregnant women with threatened preterm labour and preterm labour by using a three-dimensional (3D) ultrasound measurement of foetal adrenal gland volume enlargement, a foetal zone enlargement and cervicovaginal placental alpha microglobulin-1 (PAMG-1) test. This prospective cohort study included singleton pregnant women at 22-36+6 weeks of gestation who presented with threatened preterm labour and with preterm labour. Transabdominal 3D ultrasound measurement of the whole foetal adrenal gland and of the foetal adrenal zone were performed. Qualitative cervicovaginal PAMG-1 detection was performed at the same time. One hundred and fifty-four pregnant women were included into the study. Eighty-four pregnant women had threatened preterm labour and seventy pregnant women had preterm labour. Twenty-nine pregnant women (18%) delivered within seven days. Use of foetal adrenal gland volume enlargement, foetal zone enlargement and the PAMG-1 test in combination increased sensitivity; if one parameter was positive, the sensitivity, specificity, positive predictive value and negative predictive value were 82.8%, 27.2%, 20.9% and 87.2%, respectively, in the prediction of the timing of delivery within seven days. The combination of foetal adrenal gland enlargement and PAMG-1 increased sensitivity for the prediction of the timing of delivery within seven days in pregnant women presenting with threatened preterm labour and preterm labour. Impact Statement What is already known on this subject? An increased foetal adrenal gland volume is significantly correlated with the risk of preterm birth. What do the results of this study add? The combination of a foetal adrenal gland enlargement and a placental alpha microglobulin-1 increased sensitivity for the prediction of the timing of delivery within seven days in pregnant women presenting with threatened preterm labour and preterm labour. What are the implications of these findings for clinical practice and/or further research? The combination of a foetal adrenal gland enlargement and placental alpha microglobulin-1 may be used for the prediction of the timing of delivery within seven days in pregnant women presenting with threatened preterm labour and with preterm labour.

Concepts: Pregnancy, Childbirth, Fetus, Positive predictive value, Negative predictive value, Uterus, Sensitivity and specificity, 3D ultrasound

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Total plaque volume (TPV) measured from 3D carotid ultrasound has been shown to be able to predict cardiovascular events and is sensitive in detecting treatment effects. Manual plaque segmentation was performed in previous studies to quantify TPV, but is tedious, requires long training times and is prone to observer variability. This article introduces the first 3D direct volume-based level-set algorithm to segment plaques from 3D carotid ultrasound images. The plaque surfaces were first initialized based on the lumen and outer wall boundaries generated by a previously described semi-automatic algorithm and then deformed by a direct three-dimensional sparse field level-set algorithm, which enforced the longitudinal continuity of the segmented plaque surfaces. This is a marked advantage as compared to a previously proposed 2D slice-by-slice plaque segmentation method. In plaque boundary initialization, the previous technique performed a search on lines connecting corresponding point pairs of the outer wall and lumen boundaries. A limitation of this initialization strategy was that an inaccurate initial plaque boundary would be generated if the plaque was not enclosed entirely by the wall and lumen boundaries. A mechanism is proposed to extend the search range in order to capture the entire plaque if the outer wall boundary lies on a weak edge in the 3D ultrasound image. The proposed method was compared with the previously described 2D slice-by-slice plaque segmentation method in 26 three-dimensional carotid ultrasound images containing 27 plaques with volumes ranging from 12.5 to 450.0 mm3. The manually segmented plaque boundaries serve as the surrogate gold standard. Segmentation accuracy was quantified by volume-, area- and distance-based metrics, including absolute plaque volume difference (|ΔPV|), Dice similarity coefficient (DSC), mean and maximum absolute distance (MAD and MAXD). The proposed direct 3D plaque segmentation algorithm was associated with a significantly lower |ΔPV|, MAD and MAXD, and a significantly higher DSC compared to the previously described slice-by-slice algorithm (|ΔPV|:p=0.012, DSC: p=2.1×10-4, MAD: p=1.3×10-4, MAXD: p=5.2×10-4). The proposed 3D volume-based algorithm required 72±22 s to segment a plaque, which is 40% lower than the 2D slice-by-slice algorithm (114±18 s). The proposed automatic plaque segmentation method generates accurate and reproducible boundaries efficiently and will allow for streamlining plaque quantification based on 3D ultrasound images.

Concepts: Developmental biology, Computer graphics, 3D ultrasound, Ultrasound

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To determine fetal heart geometry during pregnancy using three-dimensional (3D) ultrasound and the spatiotemporal image correlation (STIC) rendering mode.

Concepts: Computer graphics, 3D ultrasound

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To investigate the prenatal influence of congenital heart defects (CHD) on trajectories of fetal cortical folding using three-dimensional ultrasound (3D-US).

Concepts: Embryo, 3D ultrasound, Congenital heart defect, Congenital heart disease

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In this manuscript a novel method is presented for left ventricle (LV) tracking in three-dimensional ultrasound data using a hybrid approach combining segmentation and tracking-based clues. This is accomplished by coupling an affine motion model to an existing LV segmentation framework and introducing an energy term that penalizes the deviation to the affine motion estimated using a global Lucas-Kanade algorithm. The hybrid nature of the proposed solution can be seen as using the estimated affine motion to enhance the temporal coherence of the segmented surfaces, by enforcing the tracking of consistent patterns, while the underlying segmentation algorithm allows to locally refine the estimated global motion. The proposed method was tested on a dataset composed of 24 4D ultrasound sequences from both healthy volunteers and diseased patients. The proposed hybrid tracking platform offers a competitive solution for fast assessment of relevant LV volumetric indices, by combining the robustness of affine motion tracking with the low computational burden of the underlying segmentation algorithm.

Concepts: Statistics, Developmental biology, Physics, Ventricle, 3D ultrasound, Differential geometry, Computational complexity theory, Hybrid

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The predisposition for obesity is suggested to originate in the prenatal period. Prenatal markers are needed to identify foetuses at risk for neonatal adiposity, as early marker of childhood obesity.

Concepts: Pregnancy, Infant, Embryo, Fetus, Uterus, Abortion, 3D ultrasound, Gestational age

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This article hypothesizes that it is possible to detect and diagnose both the autosomal recessive and dominant forms prenatally using ultrasound. By focusing on the characteristic phenotypical presentation, the examinator is able to diagnose the syndrome prenatally, which is of clinical importance to the parents and counseling for the consideration of terminating the pregnancy.

Concepts: Pregnancy, Embryo, Fetus, Parent, Obstetrics, 3D ultrasound, Medical ultrasonography, Prenatal diagnosis

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To assess the frequency of fetal movement and reproducibility of fetal movement counting in normal singleton pregnancies early in the second trimester using four-dimensional (4D) ultrasound.

Concepts: Pregnancy, Fetus, 3D ultrasound