A pictorial view of the three-dimensional representation and comparative two-dimensional image orientation derived from computed tomography angiography in a dog with a patent ductus arteriosus.

Patent ductus arteriosus (PDA) occlusion is one of the more common cardiovascular procedures performed in dogs. Two-dimensional imaging has been the primary method of visualizing the PDA and is the basis of its morphologic description. Transesophageal echocardiographic imaging has further characterized the three-dimensional (3D) variation in ductal morphology and shape (circle, oval). An accurate assessment of the shape and dimensions of a PDA in an individual dog is important when making decisions about definitive closure. Ductal measurements from angiography and echocardiography have not been found to be interchangeable, likely related in part to the static two-dimensional measurement of a 3D structure. We describe the use of computed tomography angiography (CTA) images imported into three software programs as a tool to provide 3D information about PDA anatomy including a comparison to images obtained from classic two-dimensional imaging modalities. These images provide an example of thorax and heart position related to transducer position and the orientation of image acquisition to demonstrate why measurements do not always compare. Additionally, 3D images are useful as a training tool and in the development of devices and training opportunities. Multidimensional imaging provides a unique representation of the 3D anatomical structure of the ductus arteriosus as displayed in these images from a dog with a PDA.

Perceptions of transcatheter device closure of patent ductus arteriosus in veterinary cardiology and evaluation of a canine model to simulate device placement: a preliminary study.

OBJECTIVES: The purpose of this study was to evaluate a canine patent ductus arteriosus (PDA) model developed for practicing device placement and to determine practices and perceptions regarding transcatheter closure of PDA from the veterinary cardiology community. METHOD: A silicone model was developed from images obtained from a dog with a PDA and device placement was performed with catheter equipment and a document camera to simulate fluoroscopy. A total of 36 individuals including 24 diplomates and 12 residents participated, and the feedback was obtained. The study included an initial questionnaire, practice with the model, observation of device placement using the model, and a follow-up questionnaire. RESULTS: A total of 92% of participants including 100% of residents indicated they did not have the opportunity to practice device placement before performing the procedure and obtained knowledge of the procedure from reading journal articles or observation. Participants indicated selecting the appropriate device size (30/36, 83%) and ensuring the device is appropriately positioned before release (18/36, 50%) as the most common areas of difficulty with device placement. Confidence level was higher after practicing with the model for residents when compared with diplomates and for participants that had performed 1-15 procedures when compared with those that had performed >15 procedures. These findings suggest those that have performed fewer procedures may benefit the most from practicing with a model. CONCLUSIONS: This preliminary study demonstrates the feasibility of a PDA model for practicing device placement and suggests that there is a potential benefit from providing additional training resources.

Perspectives on Perspective Taking: How Children Think About the Minds of Others.

Perspective taking, or "theory of mind," involves reasoning about the mental states of others (e.g., their intentions, desires, knowledge, beliefs) and is called upon in virtually every aspect of human interaction. Our goals in writing this chapter were to provide an overview of (a) the research questions developmental psychologists ask to shed light on how children think about the inner workings of the mind, and (b) why such research is invaluable in understanding human nature and our ability to interact with, and learn from, one another. We begin with a brief review of early research in this field that culminated in the so-called litmus test for a theory of mind (i.e., false-belief tasks). Next, we describe research with infants and young children that created a puzzle for many researchers, and briefly mention an intriguing approach researchers have used to attempt to "solve" this puzzle. We then turn to research examining children's understanding of a much broader range of mental states (beyond false beliefs). We briefly discuss the value of studying individual differences by highlighting their important implications for social well-being and ways to improve perspective taking. Next, we review work illustrating the value of capitalizing on children's proclivity for selective social learning to reveal their understanding of others' mental states. We close by highlighting one line of research that we believe will be an especially fruitful avenue for future research and serves to emphasize the complex interplay between our perspective-taking abilities and other cognitive processes.

Three-dimensional modeling of a patent ductus arteriosus in a cat.

A left-to-right shunting patent ductus arteriosus was diagnosed in a 13-week-old, 2.5 kg, male, domestic Shorthair cat with a continuous murmur. Echocardiographic abnormalities were identified, including: cardiomegaly, wide and presumably short ductal ampulla, and a large right branch pulmonary artery. When these findings were combined with the small patient size, additional imaging was considered prior to surgical ligation, and computed tomography angiography was preferred over standard angiography to provide multi-dimensional appreciation of the anatomy prior to surgery. The dataset from a computed tomography angiographic study performed prior to surgical ligation was used to create a three-dimensional model of the heart and great vessels. The rendered images accurately depicted the cardiac anatomy in situ, which can be utilized for surgical procedural planning and to enhance visuospatial understanding of the anatomy at all levels of training.

Perceptual learning: its importance in dentistry.

Perceptual skills are essential to the acquisition of motor skills in dentistry. The absence of these perceptual skills should be determined as early as possible and should be rectified by instruction. Programed instruction is one suitable method for teaching these skills. Perceptual discrimination will allow the learner to picture his goal or objective clearly, and it will increase his motivation by enabling him to reach this goal. Perceptual skills are necessary too for the learner to improve his performance by repetitive practice, see his mistakes, and institute corrective behavior.