A new dynamic 3D virtual methodology for teaching the mechanics of atrial septation as seen in the human heart

Three dimensional modeling of atrioventricular valves provides predictive guides for optimal choice of prosthesis

Inaccuracies in intraoperative and preoperative measurements and estimations may lead to adverse outcomes such as patient-prosthesis mismatch. We aim to measure the relation between different dimensions of the atrioventricular valve complex in explanted porcine heart models. After a detailed physical morphology study, a cast of the explanted heart models was made using silicon-based materials. Digital models were obtained from three-dimensional scanning of the casts, showing the measured annulopapillary distance was 2.50 ± 0.18 cm, and 2.75 ± 0.36 cm for anterior and posterior papillary muscles of left ventricle, respectively. There was a significant linear association between the mitral annular circumference to anterior–posterior distance (p = 0.003, 95% CI 0.78–3.06), mitral annular circumference to interpapillary distance (p = 0.009, 95% CI 0.38–2.20), anterior–posterior distance to interpapillary distance (p = 0.02, 95% CI 0.10–0.78). Anterior–posterior distance appeared to be the most important predictor of mitral annular circumference compared to other measured distances. The mean length of the perpendicular distance of the tricuspid annulus, a, was 2.65 ± 0.54 cm; b was 1.77 ± 0.60 cm, and c was 3.06 ± 0.55 cm. Distance c was the most significant predictor for tricuspid annular circumference (p = 0.006, 95% CI 0.28–2.84). The anterior–posterior distance measured by three-dimensional scanning can safely be used to predict the annular circumference of the mitral valve. For the tricuspid valve, the strongest predictor for the circumference is the c-distance. Other measurements made from the positively correlated parameters may be extrapolated to their respective correlated parameters. They can aid surgeons in selecting the optimal prosthesis for the patients and improve procedural planning.

Exploring Visualisation for Embryology Education: A Twenty-First-Century Perspective

Embryology and congenital malformations play a key role in multiple medical specialties including obstetrics and paediatrics. The process of learning clinical embryology involves two basic principles; firstly, understanding time-sensitive morphological changes that happen in the developing embryo and, secondly, appreciating the clinical implications of congenital conditions when development varies from the norm. Visualising the sequence of dynamic events in embryonic development is likely to be challenging for students, as these processes occur not only in three dimensions but also in the fourth dimensions of time. Consequently, features identified at any one timepoint can subsequently undergo morphological transitions into distinct structures or may degenerate and disappear. When studying embryology, learners face significant challenges in understanding complex, multiple and simultaneous events which are likely to increase student cognitive load. Moreover, the embryology content is very nonlinear. This nonlinear content presentation makes embryology teaching challenging for educators. Embryology is typically taught in large groups, via didactic lecture presentations that incorporate two-dimensional diagrams or foetal ultrasound images. This approach is limited by incomplete or insufficient visualisation and lack of interactivity.It is recommended that the focus of embryology teaching should instill an understanding of embryological processes and emphasise conceptualising the potential congenital conditions that can occur, linking pre-clinical and clinical disciplines together. A variety of teaching methods within case-based and problem-based curricula are commonly used to teach embryology. Additional and supplementary resources including animations and videos are also typically utilised to demonstrate complex embryological processes such as septation, rotation and folding.We propose that there is a need for embryology teaching in the twenty-first century to evolve. This is particularly required in terms of appropriate visualisation resources and teaching methodologies which can ensure embryology learning is relevant to real-world scenarios. Here we explore embryology teaching resources and methodologies and review existing evidence-based studies on their implementation and impact on student learning. In doing so, we aim to inform and support the practice of embryology educators and the learning of their students.

Learning Cardiac Embryology-Which Resources Do Students Use, and Why?

With increasing class sizes, small group activities for learning embryology are present in few institutions. How then do students supplement their lectures in order to ask and answer questions, or delve into concepts in detail? Arguably, animations and videos are ideal for visualizing four-dimensional anatomy, but how do students find and filter these? First-year medical students were surveyed with respect to the cardiac embryology component of their course and asked their opinions regarding the clinical relevance of this content and the resources they used to enhance learning. Students indicated that they considered cardiac embryology to be of relevance to clinical practice and that videos are a useful resource in helping them to learn this material. However, when seeking videos or resources, it emerged that students tended to Google information in preference to accessing online resources (or textbooks) specifically recommended by their instructor, despite students' recognition that "accuracy of information" was paramount when choosing what resource to use. While all students seemed reluctant to contact a staff member with questions, those with less proficiency in English were less likely to approach faculty for assistance. While acknowledging students as adult learners, self-regulated learning skills do not develop automatically and the development of these skills should be viewed as a "shared responsibility" between students and staff. Likewise, students also need to be taught critical appraisal of learning resources, especially in the complex online environment, with design of their bespoke institutional virtual learning environment facilitating easy identification and access of recommended resources.

Impact of cardiovascular embryology animations on short-term learning

An understanding of human embryology is essential for students to better understand the subjects of human anatomy and physiology. However, human embryology is a challenging subject for many, since they must learn how anatomic structures and physiological processes develop over a period of time. Embryology texts typically use static, two-dimensional images to illustrate the dynamic three-dimensional developmental processes, making it difficult for a student to understand spatial relationships and sequential steps. To help students conceptualize these series of complex dynamic developmental events that occur over time, two of the authors and a graphic artist developed six web-based cardiovascular embryology animations and housed them on an Indiana University website. This research study examines knowledge gains and user satisfaction of students, faculty, and laypeople around the world who accessed these six website animations. Data collection spanned 6 yr, and pretest/posttest assessments (ranging from 4 to 7 multiple-choice questions each) were used to determine immediate knowledge gains of cardiovascular embryology. The total number of completed pretest/posttest assessments ranged from 555 to 1,449 per animation. The number of correct posttest scores was significantly improved over matched pretest scores (confidence interval range 1.3-3.2, depending on the animation, P < 0.001), suggesting the animations are useful for embryology learning (at least in the short term). Demographic and user satisfaction information was gathered with an anonymous survey at the end of each animation. Survey data from all animations indicated participants found the animations easy to use and very effective for their learning. This research highlights the positive impacts of web-based animations on learning complicated events of cardiovascular embryology.

The influence of learning style in understanding analogies and 2D animations in embryology course

Undergraduate students struggle to comprehend embryology because of its dynamic nature. Studies have recommended using a combination of teaching methods to match the student's learning style. But there has been no study to describe the effect of such teaching strategy over the different types of learners. In the present study, an attempt has been made to teach embryology using the combination of analogies and simple 2D animations made with Microsoft powerpoint software. The objective of the study is to estimate the difference in academic improvement and perception scale between the different types of learners after introducing analogies and 2D animation in a lecture environment. Based on Visual, Aural, Read/Write, and Kinesthetic (VARK) scoring system the learners were grouped into unimodal and multimodal learners. There was significant improvement in post-test score among the unimodal (P<0.001) and multimodal learners (P<0.001). When the post-test score was compared between the two groups, the multimodal learners performed better the unimodal learners (P=0.018). But there was no difference in the perception of animations and analogies and long-term assessment between the groups. The multimodal learners performed better than unimodal learners in short term recollection, but in long term retention of knowledge the varied learning style didn't influence its outcome.

MRI for transformation of preserved organs and their pathologies into digital formats for medical education and creation of a virtual pathology museum. A pilot study

AIM

To evaluate the feasibility of magnetic resonance imaging (MRI) for the transformation of preserved organs and their disease entities into digital formats for medical education and creation of a virtual museum.

MATERIALS AND METHODS

MRI of selected 114 pathology specimen jars representing different organs and their diseases was performed using a 3 T MRI machine with two or more MRI sequences including three-dimensional (3D) T1-weighted (T1W), 3D-T2W, 3D-FLAIR (fluid attenuated inversion recovery), fat-water separation (DIXON), and gradient-recalled echo (GRE) sequences. Qualitative assessment of MRI for depiction of disease and internal anatomy was performed. Volume rendering was performed on commercially available workstations. The digital images, 3D models, and photographs of specimens were archived into a workstation serving as a virtual pathology museum.

RESULTS

MRI was successfully performed on all specimens. The 3D-T1W and 3D-T2W sequences demonstrated the best contrast between normal and pathological tissues. The digital material is a useful aid for understanding disease by giving insights into internal structural changes not apparent on visual inspection alone. Volume rendering produced vivid 3D models with better contrast between normal tissue and diseased tissue compared to real specimens or their photographs in some cases. The digital library provides good illustration material for radiological-pathological correlation by enhancing pathological anatomy and information on nature and signal characteristics of tissues. In some specimens, the MRI appearance may be different from corresponding organ and disease in vivo due to dead tissue and changes induced by prolonged contact with preservative fluid.

CONCLUSIONS

MRI of pathology specimens is feasible and provides excellent images for education and creating a virtual pathology museum that can serve as permanent record of digital material for self-directed learning, improving teaching aids, and radiological-pathological correlation.

Cor triatriatum sinister versus bowed septum primum in an infant with total anomalous pulmonary venous connection: a difficult imaging distinction

In cor triatriatum sinister, a membrane divides the left atrium into a posterior chamber that receives the pulmonary veins and an anterior chamber that communicates with the mitral valve. With right-side chamber overload, the septum primum can separate from the muscular septum and bow toward the left atrial cavity, leading to a thin membrane within the left atrium and imaging findings that may mimic cor triatriatum. We report the multidetector CT findings of a 3-month-old infant with a supracardiac total anomalous pulmonary venous connection with a bowed septum primum. A description of the imaging findings that distinguish cor triatriatum and bowed septum primum will be discussed. This case demonstrates the usefulness of MDCT in the assessment of supracardiac vascular anomalies and intracardiac anatomy.

Echocardiographic evaluation of patent foramen ovale prior to device closure

High-quality imaging of the atrial septum has never been so relevant to the adult cardiologist. This article focuses on the role of echocardiography in the evaluation of patent foramen ovale for closure. It provides a systematic and comprehensive approach to transesophageal echocardiographic study in such a patient. The salient information required for planning the device and equipment needed for the closure procedure are discussed.