Cell-type-resolved mosaicism reveals clonal dynamics of the human forebrain.

Debate remains around the anatomical origins of specific brain cell subtypes and lineage relationships within the human forebrain1-7. Thus, direct observation in the mature human brain is critical for a complete understanding of its structural organization and cellular origins. Here we utilize brain mosaic variation within specific cell types as distinct indicators for clonal dynamics, denoted as cell-type-specific mosaic variant barcode analysis. From four hemispheres and two different human neurotypical donors, we identified 287 and 780 mosaic variants, respectively, that were used to deconvolve clonal dynamics. Clonal spread and allele fractions within the brain reveal that local hippocampal excitatory neurons are more lineage-restricted than resident neocortical excitatory neurons or resident basal ganglia GABAergic inhibitory neurons. Furthermore, simultaneous genome transcriptome analysis at both a cell-type-specific and a single-cell level suggests a dorsal neocortical origin for a subgroup of DLX1+ inhibitory neurons that disperse radially from an origin shared with excitatory neurons. Finally, the distribution of mosaic variants across 17 locations within one parietal lobe reveals that restriction of clonal spread in the anterior-posterior axis precedes restriction in the dorsal-ventral axis for both excitatory and inhibitory neurons. Thus, cell-type-resolved somatic mosaicism can uncover lineage relationships governing the development of the human forebrain.

A comparison of student perspectives on body donation across healthcare professional programs: From prosection- to dissection-based curricula.

Donor-centered education offers students the opportunity to not only acquire visual and tactile experiences for applying anatomical knowledge but also a chance for students to reflect upon fundamental humanistic principles. The exploration of differences in students' viewpoints on body donation and the utilization of body donors in their education remains unexplored across various healthcare professional programs, which has an impact on student learning and experience. This study aimed to qualitatively examine the similarities and differences in student perspectives regarding body donation across three healthcare professional programs. One-page reflections from nursing (n = 37), physical and occupational therapy (n = 49), and medical students (n = 66) regarding their experiences in the anatomy laboratory at McGill University were collected and analyzed using a deductive approach based on themes and sub-themes outlined by Stephens et al. in 2019. Despite differences in their curricula, there were few discrepancies across the programs' reflections suggesting that donor-based learning had similar effects on each user group. Most students across the healthcare professional programs mentioned that their positive laboratory experiences motivated them to donate their bodies, extending the privilege they had to future generations. Nursing students did not reflect upon the notion that working with body donors provided unique learning experiences in the anatomy laboratory. Likewise, physical and occupational therapy (PT/OT) students did not address the importance of maintaining the privacy of body donors by covering certain body parts during lab. These findings show that prosection- and dissection-based exercises encourage reflective practices associated with these of medical ethics, highlighting an important advantage to including donor-based learning in anatomical education.

Comparison between pre-mortem and post-mortem cadaveric images for use with augmented reality headsets during dissection.

PURPOSE: Medical training has undergone many transformations to incorporate diagnostic imaging along side anatomical education. Post-mortem computed tomography (CT) scanning of body donors prior to dissection has been proposed. However, it poses challenges secondary to the embalming process and other post-mortem physiological changes that significantly alter the imaging quality. The purposes of this study were to compare the accuracy of pathology identification on pre- and post-mortem CT scans of body donors and to assess the integration of those scans in a dissection-based course, where these images were overlaid onto body donors using augmented reality (AR). METHODS: Participants in this study included 35 fourth year medical students, 5 radiology residents and 3 radiologists. A convergent, parallel mixed methods design was employed with quantitative measures that included statistical analyses of a double-blinded comparison of pathological lesions recognition, on both image sets, the group responses to a study participant survey and the login access data from imaging repository. The study also included qualitative analysis of post-elective structured interviews. RESULTS: The double-blinded comparison revealed that staff radiologists can only identify, on post-mortem images, 54.8% of the pathologies that they were able to detect on the pre-mortem scans. Analyses of the surveys and login access data reveal that 60% of radiology residents and 56% of students preferred pre-mortem scans and used those scans more often than post-mortem scans (67 access vs 36, respectively). However, post-mortem scans were significantly preferred when used to overlay onto body donors using AR (p = 0.0047). CONCLUSION: These results show that post-mortem imaging can be valuable alongside pre-mortem imaging, as they represent the most concordance between the anatomical structures and pathologies seen on the images and what is being dissected.

Evaluating AI-powered text-to-image generators for anatomical illustration: A comparative study.

Medical illustration, which involves the creation of visual representations of anatomy, has long been an essential tool for medical professionals and educators. The integration of AI and medical illustration has the potential to revolutionize the field of anatomy education, providing highly accurate, customizable images. The authors evaluated three AI-powered text-to-image generators in producing anatomical illustrations of the human skulls, heart, and brain. The generators were assessed for their accurate depiction of foramina, suture lines, coronary arteries, aortic and pulmonary trunk branching, gyri, sulci, and the relationship between the cerebellum and temporal lobes. None of the generators produced illustrations with comprehensive anatomical details. Foramina, such as the mental and supraorbital foramina, were frequently omitted, and suture lines were inaccurately represented. The illustrations of the heart failed to indicate proper coronary artery origins, and the branching of the aorta and pulmonary trunk was often incorrect. Brain illustrations lacked accurate gyri and sulci depiction, and the relationship between the cerebellum and temporal lobes remained unclear. Although AI generators tended toward esoteric imagery, they exhibited significant speed and cost advantages over human illustrators. However, improving their accuracy necessitates augmenting the training databases with anatomically correct images. The study emphasizes the ongoing role of human medical illustrators, especially in ensuring the provision of accurate and accessible illustrations.

Health profession students' outlooks on the medical profession during the COVID-19 pandemic: a global perspective.

BACKGROUND: This article summarizes a global study of the effect of the COVID-19 pandemic on junior health professions students' outlook on medicine. The pandemic has significantly affected health professions education. There is limited understanding of how students' pandemic experiences will affect them, and what impact these events may have on their career paths or the future of the professions. This information is important as it impacts the future of medicine. METHODS: In the Fall 2020 semester, 219 health professions students at 14 medical universities worldwide responded to the question: 'Has this experience (with COVID-19) changed your outlook on medicine as a profession?'. Short essay responses were semantically coded and organized into themes and subthemes using an inductive approach to thematic analysis. RESULTS: 145 responses were submitted. Themes were identified: (1) students reflected on the interaction between politics and healthcare; (2) reported becoming more aware of the societal expectations placed on healthcare professionals, including undertaking high risks and the sacrifices that healthcare professionals must make; (3) found reassurance from the recognized importance of healthcare professionals and expressed pride to be entering the profession; and (4) reflected on the current state of healthcare, including its limitations and future. CONCLUSION: Most students, independent of the extent of the pandemic in their respective countries, noted a change in their outlook regarding medicine. An overall positive outlook was noted in most junior students. Educators need to work on nurturing these sentiments and attitudes to help young students maintain a healthy relationship towards their chosen profession.

A thematic analysis of students' discussions on death and body donation in international online focus groups.

Historically, Anatomy education is an in-person discipline involving exposure to human body donors that facilitates personal and professional growth through, in part, the initiation of reflection on the topic of death. However, during the COVID-19 pandemic the decreased exposure to cadaveric anatomy for many health professions students may have influenced the depth of their individual reflections on this topic. Accordingly, this study aimed to investigate the effect of an alternate approach-focus group discussions between peers with varying degrees of exposure to cadaveric material-that may offer one strategy to stimulate deep reflection on the topic of death. A programmatic intervention was introduced, wherein students (n = 221) from 13 international universities discussed differences in their anatomy courses during small focus group sessions as part of an online exchange program. An inductive semantic thematic analysis was conducted on responses to an open-ended text-response question on how the activity influenced students' reflections about death. Resulting themes were organized into categories that described the content and topics of the students' discussions as they grappled with this sensitive topic. The students reportedly engaged in deep reflection and expressed an increased sense of connectedness with their peers, despite their disparate exposure levels to cadaveric anatomy and being physically distanced. This demonstrates that focus groups with students experiencing different laboratory contexts can be used to help all students reflect on the topic of death and that interchanges between dissecting and non-dissecting students can initiate thoughts about death and body donation among non-dissecting students.

Evaluating the integration of body donor imaging into anatomical dissection using augmented reality.

Augmented reality (AR) has recently been utilized as an integrative teaching tool in medical curricula given its ability to view virtual objects while interacting with the physical environment. The evidence for AR in medical training, however, is limited. For this reason, the purpose of this mixed method study was to evaluate the implementation of overlaying donor-specific diagnostic imaging (DSDI) onto corresponding body donors in a fourth-year, dissection-based, medical elective course entitled anatomy for surgeons (AFS). Students registered in AFS course were separated into groups, receiving either DSDI displayed on Microsoft HoloLens AR head-mounted display (n = 12) or DSDI displayed on iPad (n = 15). To test for the change in spatial ability, students completed an anatomical mental rotation test (AMRT) prior to and following the AFS course. Students also participated in a focus group discussion and completed a survey at the end of AFS, analyzed through thematic triangulation and an unpaired, Mann Whitney U test respectively, both addressing dissection experience, DSDI relevancy to dissection, and use of AR in anatomical education. Although statistically significant differences were not found when comparing student group AMRT scores, survey and discussion data suggest that the HoloLens had improved the students' understanding of, and their spatial orientation of, anatomical relationships. Trunk dissection quality grades were significantly higher with students using the HoloLens. Although students mentioned difficulties with HoloLens software, with faculty assistance, training, and enhanced software development, there is potential for this AR tool to contribute to improved dissection quality and an immersive learning experience.

The Anatomy Course During COVID-19: The Impact of Cadaver-Based Learning on the Initiation of Reflection on Death.

Background: During the COVID-19 pandemic, in-person cadaveric dissection laboratories for teaching anatomy were omitted by many schools around the world. While knowledge domains can be easily evaluated via remote exams, non-traditional discipline-independent skills such as those encouraged through reflection on the topic of death are often overlooked. This study investigated how different anatomy course formats played a role in initiating students' reflections on death during the COVID-19 pandemic. Method: In fall 2020, 217 medical, dental, premedical, and health sciences students from 13 international universities discussed differences in their anatomy courses online. Formats of anatomy courses ranged from dissection-based, prosection-based, hybrid (combination of dissection and prosection) to no laboratory exposure at all. Students' responses to the question, "Did/does your anatomy course initiate your thinking about life's passing?" were collected, and they self-reported themes that were present in their reflections on death using a multiple-choice prompt. Statistical analyses to detect differences between students with and without exposure to cadavers were performed using the chi-squared test. Results: When comparing students who had exposure to human anatomical specimens to those who had no exposure, the majority of students with exposure thought that the course did initiate thoughts about life's passing, compared to students without exposure (P < 0.05). Reflection themes were consistent across groups. Discussion: These findings indicate that anatomy dissection courses are important for the initiation of students' feelings about the topic of death. Omission of cadaveric dissection- or prosection-based laboratories will decrease the likelihood that students initiate reflection on this topic and gain important transferable skills.

Augmented-reality-guided insertion of sliding hip screw guidewire: a preclinical investigation.

BACKGROUND: The sliding hip screw (SHS) is frequently used in the management of hip fractures; successful placement depends on accurate positioning of the lag screw in the femoral head guided by fluoroscopy. We proposed to leverage the capabilities of augmented reality (AR) to overlay virtual images of the desired guidewire trajectory directly onto the surgical field to guide the surgeon during SHS guidewire insertion. METHODS: Using a commercially available AR headset and software, we performed preprocedural planning using computed tomography scans to identify the optimal trajectory for SHS guidewire insertion in the neck of a Sawbones femur model. The images of the scanned femurs containing the virtual guidewire trajectory were overlaid on the physical models such that the user could see a composite view of the computer-generated images and the physical environment. Two second-year orthopedic residents each inserted 15 guidewires under AR guidance and 15 guidewires under fluoroscopy. RESULTS: Of the 30 guidewires inserted under AR guidance, 24 (80%) were within the femoral neck, and 16 (53%) were fully enclosed within the femoral head. Nine (56%) of the 16 perforations were due to insertions that were too far along the planned trajectory. Thirteen (81%) of the successful attempts with AR had an appropriate position, compared to 25/26 (96%) with fluoroscopy. It took significantly less time to perform the procedure using fluoroscopy than AR (p < 0.05). Fluoroscopy required on average 18.7 shots. CONCLUSION: Augmented reality provides an opportunity to aid in guidewire insertion in a preplanned trajectory with less radiation exposure in a sterile environment, but technical challenges remain to be solved to enable widespread adoption.

10 tips on working with human body donors in medical training and research.

Human body donors selflessly decided to make the ultimate gift to donate their bodies to education. Being on the receiving end, the health sciences education community owes it to the donors to ensure that they are being treated with utmost respect by promoting and developing high ethical standards and maximizing the benefits from this gift. Working with human body donors for research purposes has increased over the years, while regulations associated with these processes did not change. This article draws upon current literature and author's experiences to offer practical tips for health educators and everyone working with body donors to achieve these goals. We offer 10 practical tips that help in starting the conversation about the best ways to work with body donors to maximize their contribution to health sciences education.

From 1883 to 2019; Variables Influencing Body Procurement at McGill University.

McGill University has continued to maintain whole body dissection as an integral component of its medical school curriculum. To better explore the factors influencing body procurement at McGill University, records of body receipts were collected from their paper and electronic records and analyzed from 1883 to 2019. The data collected allowed for discussion on the number of bodies received at McGill University each year, the age at death of the bodies, their sex, as well as religious affiliation and language spoken at home. As bodies of the deceased have a long held and unique status in law, this information was considered in light of historical and legislative data and, in the case of religion and language, it was compared to census data for Montréal, Québec, Canada. Overall numbers of bodies procured by McGill University have varied throughout the years, with no discernable target number over time. The current body donor profile at McGill University is likely to be a male in his 70's and likely to speak French at home. However, the strong connection of the University with the Anglophone community of Montréal is reflected by the significantly higher proportion of English-speaking donors when compared to the general population of the city. In regard to legislation, it appears that the most recent legislations did not affect the rate of procurement. However, when legislations were embraced by religious institutions in 1883, there was a 261% increase in bodies sent for dissection, over the following two decades.

Scoping review: The use of augmented reality in clinical anatomical education and its assessment tools.

The purpose of this review was to identify the different augmented reality (AR) modalities used to teach anatomy to students, health professional trainees, and surgeons, and to examine the assessment tools used to evaluate the performance of various AR modalities. A scoping review of four databases was performed using variations of: (1) AR, (2) medical or anatomical teaching/education/training, and (3) anatomy or radiology or cadaver. Scientific articles were identified and screened for the inclusion and exclusion criteria as per Preferred Reporting Items for Systematic Reviews and Meta-Analyses with extension for scoping reviews guidelines. Virtual reality was an exclusion criterion. From this scoping review, data were extracted from a total of 54 articles and the following four AR modalities were identified: head-mounted display, projection, instrument and screen, and mobile device. The usability, feasibility, and acceptability of these AR modalities were evaluated using a variety of quantitative and qualitative assessment tools. Within more recent years of AR integration into anatomy education, the assessment of visuospatial ability, cognitive load, time on task, and increasing academic achievement outcomes are variables of interest, which continue to warrant more exploration. Sufficiently powered studies using validated assessment tools must be conducted to better understand the role of AR in anatomical education.

Needle-free Mental Incisive Nerve Block:In vitro, Cadaveric, and Pilot Clinical Studies.

The present study aimed to optimize Needle-Free Liquid Jet Injection (NFLJI) for Mental Incisive Nerve Blocks (MINB) and evaluate its clinical safety and feasibility. A MINB protocol was developed and optimized by series of NFLJI experiments in soft tissue phantoms and cadavers, then validated in two pilot Randomized Controlled Trials (RCT). The NFLJI penetration depth was found to be directly proportional to the supply pressure and volume. High-pressure NFLJIs (620 kPa or above) created maximum force and total work significantly greater than needle injections. Low-pressure NFLJIs (413 kPa), however, produced results similar to those of needle injections. Additionally, high-pressure NFLJIs created jet impingement pressure and maximum jet penetration pressure higher than low-pressure NFLJIs. Pilot RCTs revealed that high-pressure NFLJI caused a high risk of discomfort (60%) and paresthesia (20%); meanwhile, low-pressure NFLJI was less likely to cause complications (0%). The preliminary success rates of MINB from cadavers using NFLJIs and needles were 83.3% and 87.5%. In comparison, those from RCTs are 60% and 70%, respectively. To conclude, NFLJI supply pressure can be adjusted to achieve effective MINB with minimal complications. Furthermore, the cadaver study and pilot RCTs confirmed the feasibility for further non-inferiority RCT.

3D Printed Heart Models Illustrating Myocardial Perfusion Territories to Augment Echocardiography and Electrocardiography Interpretation.

Visualizing the vascular territories of coronary arteries during echocardiography or electrocardiography (ECG) requires trainees to mentally relate and overlay 2D sonographic images or cardiac lead projections with 3D anatomical representations of the ventricular walls and their respective blood supply. To facilitate the acquisition of these competencies, this study focuses on the feasibility of developing low-cost, open-sourced 3D printed heart models with standard ultrasound views or ECG lead projections illustrating the myocardial perfusion territories. A 3D digital heart model was cut to reflect the typical cardiac ultrasound views. The 4-chamber view model was further punctured for the paths of the precordial and limb leads of an ECG. Painting coronary arteries on the surface and internal views of the 3D prints illustrated vessel territories. Students, residents, and staff were surveyed during bedside ultrasound simulation sessions and ECG teaching half-days. Results demonstrated clear appreciation of 3D printed models, which suggests such models can easily be implemented by other institutions to augment trainees' experience during skill acquisition.

Hepatic Hilar Nerve Block for Hepatic Interventions: Anatomy, Technique, and Initial Clinical Experience in Thermal Ablation of Liver Tumors.

Background Image-guided procedures for treatment of liver diseases can be painful and require heavy sedation of the patient. Local-regional nerve blocks improve pain control and reduce oversedation risks, but there are no documented liver-specific nerve blocks. Purpose To develop a safe and technically simple liver-specific nerve block. Materials and Methods Between March 2017 and October 2019, three cadavers were dissected to evaluate the hepatic hilar anatomy. The hepatic hilar nerves were targeted with transhepatic placement of a needle adjacent to the main portal vein, under US guidance, and evaluated with use of an injection of methylene blue. A hepatic nerve block, using similar technique and 0.25% bupivacaine, was offered to patients undergoing liver tumoral ablation. In a prospective pilot study, 12 patients who received the nerve block were compared with a control group regarding complications, safety, pain scores, and intraoperative opioid requirement. Student t tests were used to compare the groups' characteristics, and Mann-Whitney U tests were used for the measured outcomes. Results Cadaver results confirmed that the hepatic nerves coursing in the hepatic hilum can be targeted with US for injection of anesthetic agents, with adequate spread of injected methylene blue around the nerves in the hepatic hilar perivascular space. The 12 participants (mean age ± standard deviation, 66 years ± 13; eight men) who received a hepatic hilar block before liver thermal ablations demonstrated reduced pain compared with a control group of 12 participants (mean age, 63 years ± 15; eight men) who received only intravenous sedation. Participants who received the nerve block had a lower mean visual analog scale score for pain than the control group (3.9 ± 2.4 vs 7.0 ± 2.8, respectively; P = .01) and decreased need for intraprocedural fentanyl (mean dose, 152 µg ± 78.0 vs 235.4 µg ± 58.2, respectively; P = .01). No major complications occurred in the hepatic hilar nerve block group. Conclusion A dedicated hepatic hilar nerve block with 0.25% bupivacaine can be safely performed to provide anesthesia during liver tumoral ablation. © RSNA, 2021.

Needle-free injection: Dental infiltration anesthesia.

This study aimed to develop an optimal Needle-Free Liquid Jet Injection (NFLJI) technique for dental infiltration anesthesia and evaluate its clinical safety and feasibility. The fluid dynamics of NFLJI in the dentoalveolar region were investigated using soft tissue phantoms supported by rigid glass. NFLJIs were performed at different incident angles and recorded using a high-speed camera. Accordingly, an optimal NFLJI for infiltration anesthesia was developed and validated on cadavers, then assessed in two pilot Randomized Controlled Trials (RCT): one for validating the safety of optimal NFLJI technique, the other for evaluating its feasibility and safety. High-speed videos showed that perpendicular NFLJIs induced significantly more regurgitation than oblique NFLJIs, which was confirmed in cadavers. Clinical trials revealed that perpendicular NFLJIs induced a high risk of bleeding (83.3%) and laceration (83.3%), whereas oblique NFLJIs induced a low risk of bleeding (33.3%) and laceration (16.7%). Moreover, the preliminary success rates of oblique NFLJIs and needle injections were both 83.3%. The recruitment took 3-5 weeks with a rate of 100%. Oblique NFLJIs could be a promising approach for dental infiltration anesthesia, causing minimal drug regurgitation with a relatively low risk of complication. The pilot RCTs confirmed the feasibility for conducting a non-inferiority RCT.

Alternatives to Student Outbound Mobility-Improving Students' Cultural Competency Skills Online to Improve Global Health Without Travel.

Introduction: Student outbound mobility is a major element in internationalization of medical education and global health education. However, this approach is often criticized, as it is inherently inequitable. Internationalization at home is a newer concept that aims to provide students with international skills and experiences without exchange travel. We report detailed outcomes of an international online program during the COVID-19 pandemic, which aimed to include acquisition of cultural awareness and competency-similar to what the students would have obtained if they had travelled abroad. Method: Sixty-eight students from 12 international universities participated in international small peer group collaborative work, and online networking. Perceived improvement of cultural competency using Likert scale and open-ended questions was used as a measure of success. Furthermore, students' definition of cultural competency in the different countries was obtained. Results: Students improved their cultural competency skills. Data analysis supported statistically significant improvement of the above skills after the program, in comparison to the start of the program. Discussion: Internationalization of medical education can be achieved at home-via structured online peer exchanges-and can provide students with intercultural skills and networking opportunities that are typically achieved via international in-person travel. The above represents a socially just and equitable way to reach all students and can result in improvement of their cultural competency, preparing them for their work in global health, and thereby resulting in improvement of global health. Supplementary Information: The online version contains supplementary material available at 10.1007/s40670-021-01332-9.

Initiating Students' Reflections on Life's Passing in the Anatomy Course - an International Observation at 14 Universities.

BACKGROUND: Medical and dental students' feelings and thoughts about the topic of death and life's passing are often associated with learning in the gross anatomy course, when students begin working with a deceased body donor in order to study human anatomy. Little is known of whether the format of anatomy teaching has an impact on these experiences. An observational study was performed to capture the initiation of students' sentiments on the topic of life's passing during the anatomy course at 14 international universities, identify common themes regarding these thoughts, and to study the connection to variations in anatomy course formats and included elements. METHOD: Preclinical anatomy students reflected on one question (i.e., "How did your experience in the anatomy laboratory bring about your reflections on the meaning of life and human existence as well as the sanctity of one's passing?"). Written assignments were collected and anonymously coded. Information on anatomy courses was obtained via faculty questionnaires. RESULT: A variety of themes were identified at the different schools, correlated with different anatomy formats and elements. Results indicate that the courses that offer hands-on cadaveric dissections may play an important role in triggering these sentiments. DISCUSSION: The initiation of students' sentiments about the topic of death varies and includes several themes. There can be a connection to the way anatomy is taught, particularly if hands-on comprehensive cadaveric dissection or prosections are included. CONCLUSION: In summary, anatomy courses can initiate students' thinking about life's passing - particularly in schools that offer hands-on cadaveric dissections or prosections.

An Observation of Healthcare Professions Students' Perceptions During the COVID-19 Pandemic.

This study conveys preclinical healthcare professions students' sentiments at 14 universities during the 2020 COVID-19 pandemic. Essays about students' thoughts and experiences were thematically sorted and revealed a variety of sentiments spanning from positive (e.g., pride, respect) to the more negative (e.g., anxiety, guilt, disappointment, anger). Themes revealed respect for the healthcare profession, but also the realization of its limitations, sacrifices, and risks. Healthcare profession educators need to be aware that the COVID-19 pandemic has affected students emotionally and may have long-term effects on the global healthcare profession. This study can serve as a historic documentation of how this generation of students felt and adds to the literature on how the pandemic affected the healthcare profession.