Fetal face shape analysis from prenatal 3D ultrasound images.

3D ultrasound imaging of fetal faces has been predominantly confined to qualitative assessment. Many genetic conditions evade diagnosis and identification could assist with parental counselling, pregnancy management and neonatal care planning. We describe a methodology to build a shape model of the third trimester fetal face from 3D ultrasound and show how it can objectively describe morphological features and gestational-age related changes of normal fetal faces. 135 fetal face 3D ultrasound volumes (117 appropriately grown, 18 growth-restricted) of 24-34 weeks gestation were included. A 3D surface model of each face was obtained using a semi-automatic segmentation workflow. Size normalisation and rescaling was performed using a growth model giving the average size at every gestation. The model demonstrated a similar growth rate to standard head circumference reference charts. A landmark-free morphometry model was estimated to characterize shape differences using non-linear deformations of an idealized template face. Advancing gestation is associated with widening/fullness of the cheeks, contraction of the chin and deepening of the eyes. Fetal growth restriction is associated with a smaller average facial size but no morphological differences. This model may eventually be used as a reference to assist in the prenatal diagnosis of congenital anomalies with characteristic facial dysmorphisms.

Quantitating skill acquisition with optical ultrasound simulation.

OBJECTIVE: To investigate and compare the effect of simulator training on quantitative scores for ultrasound-related skills for trainees with novice level ultrasound experience and expert ultrasound operators. METHODS: Three novice (comprising of 11, 32, 23 participants) and one expert (10 participants) subgroups undertook an ultrasound simulation training session. Pre- and post-training test scores were collected for each subgroup. Outcome measures were as follows: mean accuracy score for obtaining the correct anatomical plane, percentage of correctly acquired target planes, mean number of movements, time to achieve image, distance travelled by probe and accumulated angling of the probe. RESULTS: The novices showed improvement in image acquisition after completion of the simulation training session with an improvement in the rate of correctly acquired target planes from 28-57% to 39-83%. This was not replicated in the experts. The novice's individual ratios based on pre- vs. post-training metrics improved between 1.7- and 4.3-fold for number of movements, 1.9- and 6.7-fold for distance, 2.0- and 5.2-fold for time taken and 1.8- and 7.3-fold for accumulated angling. Among the experts, there was no relationship between pre-training simulator metrics and years of ultrasound experience. CONCLUSIONS: The individual simulation metrics suggest the sessions were delivered at an appropriate level for basic training as novice trainees were able to show demonstrable improvements in both efficiency and accuracy on the simulator. Experts did not improve after the simulation modules, and the novice scores post-training were similar to those of experts, suggesting the exercises were valid in testing ultrasound skills at novice but not expert level.

So much to do and so little time. Effort and perceived temporal distance.

In a series of five experiments, we showed that the perception of temporal distance to a future event is shaped by the effort one must invest to realize the event. Studies 1a and 1b showed that when actors are faced with realizing an event by a certain deadline, more effortful events are perceived as closer in time, regardless of the objective temporal distance to the deadline. This negative relationship was reversed, however, when deadlines were absent (Study 2). Finally, priming high effort reduced perceived temporal distance to an event, whereas priming low effort increased perceived temporal distance to the event (Studies 3 and 4). The implications of these findings for models of temporal distance are discussed.

Stereotypes help people connect with others in the community: a situated functional analysis of the stereotype consistency bias in communication.

Communicators tend to share more stereotype-consistent than stereotype-inconsistent information. The authors propose and test a situated functional model of this stereotype consistency bias: stereotype-consistent and inconsistent information differentially serve 2 central functions of communication--sharing information and regulating relationships; depending on the communication context, information seen to serve these different functions better is more likely communicated. Results showed that stereotype-consistent information is perceived as more socially connective but less informative than inconsistent information, and when the stereotype is perceived to be highly shared in the community, more stereotype-consistent than inconsistent information is communicated due to its greater social connectivity function. These results highlight the need to examine communication as a dynamic and situated social activity.