Relationship between the relative timing of prosection and dissection experiences and laboratory examination performance in a gross anatomy course.

Reduced hours of instruction are reported within the gross anatomy education literature. Anatomy instruction continues to be challenged with motivating and inspiring learners to value the contribution of gross anatomy knowledge to their career development alongside increased organizational demands for efficiency and effectiveness. To address these demands, this retrospective study sought to understand how the relative timing and amount of gross anatomy instruction were related to examination performance. Undergraduate and graduate students between 2018 and 2022 were assigned to three cohorts determined by enrollment in prosection-based anatomy only (n = 334), concurrent enrollment in prosection- and dissection-based anatomy in the same semester (n = 67), or consecutive enrollment in the courses one year apart (n = 43). Concurrent students had higher prosection-based anatomy examination scores than prosection-only and consecutive students. Consecutively, enrolled students outperformed concurrently enrolled students on the first two dissection examinations but showed no performance differences on the third and fourth dissection examinations. While the results on the timing and presentation of anatomical instruction were inconclusive, the results do support increased instructional time using both prosection and dissection modalities concurrently to improve performance on identification-based gross anatomy examinations.

Exploring consistent ratios in morphometry of the proximal tibia: insights for knee arthroplasty.

INTRODUCTION: The current study, which delves into proximal tibia morphometric parameters in a Greek sample, not only analyzes whether specific linear distance ratios are consistent but also paves the way for a potential novel metric system for knee arthroplasty imaging studies using constant ratios. These findings could have significant implications for future enlarged research and clinical practice. METHODS: A total of 38 dried tibiae were evaluated by two independent investigators. The following distances were measured with a digital Vernier sliding caliper: (1) the mediolateral distance of the proximal surface (A), (2) the anteroposterior distance of the proximal surface (B), (3) The longitudinal length of the bone (C), (4) the line connecting the anterior margin of the proximal surface with the highest peak of the tibia tuberosity (D), (5) the depth of the proximal margin of the medial articular facet (AF) (medial plateau) (E) and (6) the depth of the proximal margin of the lateral AF (lateral plateau) (F). RESULTS: The A, B, C, D, E, and F mean distances were 71.3 mm, 47.4 mm, 340.2 mm, 37.1 mm, 42 mm, and 35.9 mm. Reliability analysis for each observer on all measurements revealed an interclass correlation (ICC) score of 0.975 (observer 1) and 0.971 (observer 2). The ratio A/B was 1.5, A/C was a constant 0.2, and D/C was 0.1. The ratio E/F was 1.2. The six measurements (A-F) showed excellent inter-observer reliability (all ICC values > 0.990). CONCLUSIONS: The study established constant ratios of the studied linear distances around the proximal tibia. Considering these ratios, asymmetrical tibial components in knee arthroplasty seem to replicate the native anatomy more closely. Furthermore, the distance from the anterior margin of the proximal surface to the tibial tuberosity peak, constituting one-tenth of the longitudinal length of the tibia, shows promise as a metric system for imaging studies, especially in assessing lesions around tibial components.

Dimension, Location and Clinical Importance of Supraorbital Foramen and Notch: A Combined Cadaveric and Dry Skull Study.

PURPOSE: The exit points of the supraorbital nerve and its branches hold significant importance in various medical procedures, including supraorbital endoscopic surgeries, forehead-facial aesthetic plastic surgeries, medical aesthetic applications and maxillofacial surgeries. Therefore, the primary objective of the present study was to precisely define the dimension, location and clinical significance of the supraorbital foramen/notch. By doing so, we aimed to enhance our understanding of this anatomical structure and its implications for surgical and aesthetic interventions in the supraorbital region. METHODS: For our study, we conducted anatomical dissections and bone measurements to assess the significance of anatomical variations of the supraorbital foramen/notch. We utilized a sample consisting of 28 cadavers and 38 skulls. The supraorbital foramen/notch was bilaterally analyzed in all 28 cadavers and 38 dry bones. We morphometrically analyzed the distance between the supraorbital foramen/notch and various anatomical landmarks, including the nasion, supraorbital margin, infraorbital margin, temporal crest, glabella, frontal cavity and midline of the face. Additionally, we measured the distance between the supraorbital foramen/notches and the frontal foramen/notches, and the width of the supraorbital foramen/notch and the distance between both supraorbital foramina/notches. RESULTS: There are 32 (57.14%) supraorbital  foramina, and the remaining are 24 (42.86%) supraorbital notches in cadavers and there are 36 (47.37%) supraorbital foramina, and the remaining are 40 (52.63%) supraorbital notches in skulls. We observed consistency in the dimension and location values of anatomical measurement parameters between cadavers and dry skulls on both right and left sides, with the exception of the parameter "distance from temporal crest" (p=0.042). Furthermore, our correlation analysis revealed a significant positive relationship between the right and left sides across all parameters, except for the following instances: in dry skulls, "distance from supraorbital margin" and in cadaver parameters, "distance from temporal crest, " "distance from frontal cavity" and "width." CONCLUSION: In our study, we observed that the distributions of supraorbital foramina and notches were nearly similar. Furthermore, our findings indicated comparable measurements between the right and left sides in both cadavers and skulls. These results suggest a degree of consistency in supraorbital anatomy within our study sample, regardless of the specimen type (cadavers or skulls) or laterality (right or left side). NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Medical students' preferences for asynchronous online or face-to-face learning strategies in learning gross anatomy and neuroanatomy during the COVID-19 pandemic.

Gross anatomy and neuroanatomy are fundamental subjects in medical education. However, learning different anatomical terms and understanding the complexity of the subjects are often challenging for medical students. At National Taiwan University, the 2020-2021 cohort adopted a face-to-face (F2F) learning strategy for gross anatomy and neuroanatomy lecture and laboratory courses until May 17, 2021. After the aforementioned date, the same cohort learned the rest of the gross anatomy and neuroanatomy courses via asynchronous online learning. This study aimed to evaluate the benefits of and students' preferences for F2F and asynchronous online learning strategies in learning gross anatomy and neuroanatomy. A survey with closed-ended and open-ended questions was used to quantitatively and qualitatively explore medical students' learning preferences for two teaching strategies in gross anatomy and neuroanatomy. The results identified different learning preferences among students in learning gross anatomy and neuroanatomy-satisfied with both learning strategies, satisfied with only F2F learning strategy, satisfied with only asynchronous online learning strategy, and satisfied with neither learning strategy. The survey results with closed-ended and open-ended questions showed that medical students preferred F2F learning for anatomical laboratory courses but favored asynchronous online learning for neuroanatomical laboratory courses. In addition, medical students considered peer discussion more critical in learning gross anatomy than neuroanatomy. These findings provide valuable information about medical students' preference for gross anatomy and neuroanatomy courses, which anatomy teachers can consider when planning to enhance their curriculum in the future.

Optimizing group work strategies in virtual dissection.

Due to its haptic and interactive nature, virtual anatomy provides an opportunity for small-group learning, enabling students to develop their group work skills before they graduate. However, there is currently little practical guidance supported by pedagogic principles detailing how to incorporate it into curricula. Anatomy educators at the University of Plymouth conducted action research aiming to capture students' overall perceptions of the virtual anatomy platform Anatomage. Questioning the benefits and challenges students face while interacting with Anatomage prompted the creation of evidence-based interventions to be later evaluated. Although a plethora of themes were identified, this report specifically examines those relating to group work. Thematic analysis of initial focus group data found group size and group dynamics impacted students' experience with the platform. Following the implementation of interventions to resolve these issues, a questionnaire and second series of focus groups were conducted to determine whether they were successful. Additional subthemes found from these data included facilitation, social pressure, peer learning and working with friends. This study contributed to the improvement of small group learning and integration of virtual anatomy into curricula based on student and staff feedback. As such, these data support the development of effective group working skills which are fundamental for healthcare professionals and widely recognized by regulators such as the General Medical Council and Health and Care Professions Council. In this report, the authors provide practical advice informed by pedagogy and principles from management and psychology to provide a multidisciplinary perspective.

Predicting performance in a doctor of physical therapy gross anatomy course based on an exploratory factor analysis of the anatomical self-efficacy instrument.

Measuring self-efficacy can be a valuable means for instructors to predict student performance. However, it is crucial to measure self-efficacy within specific contexts to effectively gauge students' perceptions of their capabilities. This study evaluated the factors comprising the Anatomical Self-Efficacy Instrument (ASEI) and determined whether these factors could predict performance in gross anatomy. Three cohorts of Doctor Physical Therapy (DPT) students completed the ASEI at the start of gross anatomy. An exploratory factor analysis (EFA) analyzed the ASEI's dimensionality, and Cronbach's alpha evaluated the internal consistency of the extracted factors. Linear regression was used to determine whether ASEI's total or subdomain scores predicted final anatomy course performance scores. In total, 142 of 287 (49.5%) DPT students completed the ASEI. EFA revealed three distinct factors, including "cognitive," "psychomotor," and "clinical anatomy self-efficacy", and explained 44.9%, 13.7%, and 5.2% of the total variance, respectively. Only cognitive self-efficacy predicted final gross anatomy course performance (ß = 0.34; R2 = 0.071; F(3,138) = 3.51; p < 0.05). Overall, the ASEI's 3-factor solution implies its multidimensionality, a finding that could inform the development of more comprehensive self-efficacy measures. Notably, "cognitive self-efficacy" was the only subdomain that predicted DPT student performance in anatomy, suggesting its potential as a tool for identifying students in need of additional learning support. The ASEI's practical usability should be further explored through additional psychometric testing.

Identification and characterization of a new species of Taxus - Taxus qinlingensis by multiple taxonomic methods.

BACKGROUND: The taxonomy of Taxus Linn. remains controversial due to its continuous phenotypic variation and unstable topology, thus adversely affecting the formulation of scientific conservation strategies for this genus. Recently, a new ecotype, known as Qinling type, is mainly distributed in the Qinling Mountains and belongs to a monophyletic group. Here, we employed multiple methods including leaf phenotype comparison (leaf shapes and microstructure), DNA barcoding identification (ITS + trnL-trnF + rbcL), and niche analysis to ascertain the taxonomic status of the Qinling type. RESULTS: Multiple comparisons revealed significant differences in the morphological characters (length, width, and length/width ratio) among the Qinling type and other Taxus species. Leaf anatomical analysis indicated that only the Qinling type and T. cuspidata had no papilla under the midvein or tannins in the epicuticle. Phylogenetic analysis of Taxus indicated that the Qinling type belonged to a monophyletic group. Moreover, the Qinling type had formed a relatively independent niche, it was mainly distributed around the Qinling Mountains, Ta-pa Mountains, and Taihang Mountains, situated at an elevation below 1500 m. CONCLUSIONS: Four characters, namely leaf curvature, margin taper, papillation on midvein, and edges were put forward as primary indexes for distinguishing Taxus species. The ecotype Qingling type represented an independent evolutionary lineage and formed a unique ecological niche. Therefore, we suggested that the Qingling type should be treated as a novel species and named it Taxus qinlingensis Y. F. Wen & X. T. Wu, sp. nov.

Marfan and Loeys-Dietz aortic phenotype: A potential tool for diagnosis and management.

Objective: In heritable aortic diseases, different vascular involvement may occur with potential variable implications in aortic dilation/dissection risk. This study aimed to analyze the aortic anatomy of individuals with Marfan syndrome and Loeys-Dietz syndrome to identify possible morphological differences. Methods: Computed tomography and magnetic resonance imaging of the thoracoabdominal aorta from the proximal supra-aortic vessels to the femoral bifurcation level of 114 patients with Marfan and Loeys-Dietz syndromes and 20 matched control subjects were examined. Aortic diameters, areas, length, and tortuosity were measured in different aortic segments using specific vessel analysis software. Results: Patients with Marfan syndrome showed a higher prevalence of ascending aorta and aortic root dilation (P = .011), larger and longer aortic roots (P = .013) with pear-shaped phenotype, larger isthmus/descending aorta diameter ratio (P = .015), and larger suprarenal aorta and iliac arteries. Patients with Loeys-Dietz syndrome showed longer indexed segments and a significantly longer arch (P = .006) with type 2/3 arch prevalence (P = .097). Measurement ratios analysis provided cut-off values (aortic root to ascending aorta length/aortic root diameter, aortic root/sinotubular junction, aortic root/ascending aorta diameter) differentiating patients with Marfan syndrome from patients with Loeys-Dietz syndrome, even in the early stage of the disease. Conclusions: Both syndromes show peculiar anatomic patterns at different aortic levels irrespective of aortic dilation and disease severity. These features may represent the expression of different genetic mutations on aortic development, with a potential impact on prognosis and possibly contributing to better management of the diseases. The systematic adoption of whole body imaging with magnetic resonance or computed tomography should always be considered, because they allow a complete vascular assessment with practical indicators of differential diagnosis.

The anterior sylvian point as a reliable landmark for the anterior temporal lobectomy in mesial temporal lobe epilepsy: technical note, case series, and cadaveric dissection.

Introduction: Mesial temporal lobe epilepsy (MTLE) is one of the most prevalent forms of focal epilepsy in surgical series, particularly among adults. Over the decades, different surgical strategies have been developed to address drug-resistant epilepsy while safeguarding neurological and cognitive functions. Among these strategies, anterior temporal lobectomy (ATL), involving the removal of the temporal pole and mesial temporal structures, has emerged as a widely employed technique. Numerous modifications have been proposed to mitigate the risks associated with aphasia, cognitive issues, and visual field defects. Methods: Our approach is elucidated through intraoperative and cadaveric dissections, complemented by neuroradiological and cadaveric measurements of key anatomical landmarks. A retrospective analysis of patients with drug-resistant MTLE who were treated using our ATL technique at IRCCS Neuromed (Pozzilli) is presented. Results: A total of 385 patients were treated with our ATL subpial technique anatomically focused on the anterior Sylvian point (ASyP). The mean FU was 9.9 ± 5.4 years (range 1-24). In total, 84%of patients were free of seizures during the last follow-up, with no permanent neurological deficits. Transient defects were as follows: aphasia in 3% of patients, visual field defects in 2% of patients, hemiparesis in 2% of patients, and cognitive/memory impairments in 0.8% of patients. In cadaveric dissections, the ASyP was found at a mean distance from the temporal pole of 3.4 ± 0.2 cm (range 3-3.8) at the right side and 3.5 ± 0.2 cm (3.2-3.9) at the left side. In neuroimaging, the ASyP resulted anterior to the temporal horn tip in all cases at a mean distance of 3.2 ± 0.3 mm (range 2.7-3.6) at the right side and 3.5 ± 0.4 mm (range 2.8-3.8) at the left side. Discussion: To the best of our knowledge, this study first introduces the ASyP as a reliable and reproducible cortical landmark to perform the ATL to overcome the patients' variabilities, the risk of Meyer's loop injury, and the bias of intraoperative measurements. Our findings demonstrate that ASyP can be a safe cortical landmark that is useful in MTLE surgery because it is constantly present and is anterior to risky temporal regions such as temporal horn and language networks.

A novel theory for rapid localization of the transverse-sigmoid sinus junction and "keyhole" in the retrosigmoid keyhole approach: micro-anatomical study, technique nuances, and clinical application.

To determine a rapid and accurate method for locating the keypoint and "keyhole" in the suboccipital retrosigmoid keyhole approach. (1) Twelve adult skull specimens were selected to locate the anatomical landmarks on the external surface of the skull.The line between the infraorbital margin and superior margin of the external acoustic meatus was named the baseline. A coordinate system was established using the baseline and its perpendicular line through the top point of diagastric groove.The perpendicular distance (x), and the horizontal distance (y) between the central point of the "keyhole" and the top point of the digastric groove in that coordinate system were measured. The method was applied to fresh cadaveric specimens and 53 clinical cases to evaluate its application value. (1) x and y were 14.20 ± 2.63 mm and 6.54 ± 1.83 mm, respectively (left) and 14.95 ± 2.53 mm and 6.65 ± 1.61 mm, respectively (right). There was no significant difference between the left and right sides of the skull (P > 0.05). (2) The operative area was satisfactorily exposed in the fresh cadaveric specimens, and no venous sinus injury was observed. (3) In clinical practice, drilling did not cause injury to venous sinuses, the mean diameter of the bone windows was 2.0-2.5 cm, the mean craniotomy time was 26.01 ± 3.46 min, and the transverse and sigmoid sinuses of 47 patients were well-exposed. We propose a "one point, two lines, and two distances" for "keyhole" localization theory, that is we use the baseline between the infraorbital margin and superior margin of the external acoustic meatus and the perpendicular line to the baseline through the top point of the digastric groove to establish a coordinate system. And the drilling point was 14.0 mm above and 6.5 mm behind the top point of the digastric groove in the coordinate system.

Yet another dose algorithm (YODA) for independent computations of dose and dose changes due to anatomical changes.

Objective:To assess the viability of a physics-based, deterministic and adjoint-capable algorithm for performing treatment planning system independent dose calculations and for computing dosimetric differences caused by anatomical changes. Approach:A semi-numerical approach is employed to solve two partial differential equations for the proton phase-space density which determines the deposited dose. Lateral hetereogeneities are accounted for by an optimized (Gaussian) beam splitting scheme. Adjoint theory is applied to approximate the change in the deposited dose caused by a new underlying patient anatomy. Main results:The quality of the dose engine was benchmarked through three-dimensional gamma index comparisons against Monte Carlo simulations done in TOPAS. The worst passing rate for the gamma index with (1 mm, 1 %, 10 % dose cut-off) criteria is 94.55 %. The effect of delivering treatment plans on repeat CTs was also tested. For a non-robustly optimized plan the adjoint component was accurate to 5.7 % while for a robustly optimized plan it was accurate to 4.8 %. Significance:YODA is capable of accurate dose computations in both single and multi spot irradiations when compared to TOPAS. Moreover, it is able to compute dosimetric differences due to anatomical changes with small to moderate errors thereby facilitating its use for patient-specific quality assurance in online adaptive proton therapy.

Transcatheter closure of multiple coronary artery fistulas: a coronary computed tomography angiography-based anatomic classification.

INTRODUCTION AND OBJECTIVES: This study aimed to retrospectively analyze the anatomical characteristics and classification of multiple coronary artery fistulas (MCAFs), and to compare the outcomes of transcatheter closure between MCAFs and single fistulas. METHODS: All patients who underwent attempts at transcatheter closure of coronary artery fistulas (CAFs) at Fuwai Hospital from 2010 to 2023 were retrospectively reviewed. Patients were categorized into single fistula and MCAFs groups, and anatomical characteristics and transcatheter closure outcomes were compared between the 2 groups. RESULTS: This retrospective study included 146 patients who underwent attempted transcatheter closure of CAFs, with a 14.38% failure rate. Among the 146 patients with CAFs, 32.19% were identified as having MCAFs, with types I, II, and III constituting 40.43%, 42.55%, and 17.02%, respectively. Unlike single fistulas, which predominantly originated from the right coronary artery and terminated in the left ventricle, MCAFs mainly had simultaneous origins from the right coronary artery and left anterior descending artery (29.79%), and predominantly drained into the pulmonary artery (70.21%), with a notable prevalence of plexus-like morphology (38.3% vs 2.02%, P < .001). The success rate of transcatheter closure was significantly lower for multiple fistulas compared with single fistula (64.29% vs 84.34%, P = .011). Multivariate regression analysis indicated that the risk of closure failure for MCAFs was 2.64 times that of single fistulas. CONCLUSIONS: MCAFs are common among CAFs and can be classified into 3 types based on the number and location of their origins and terminations. The risk of failure of transcatheter closure is significantly higher in MCAFs than in single fistulas.

How I do it: Endoscopic endonasal resection of the medial wall of the cavernous sinus.

BACKGROUND: Resection of the medial wall of the cavernous sinus (MWCSR) is a growing surgical maneuver for the radical removal of pituitary adenomas. METHOD: We present a simple modification of the technique following the two dural layers of the floor of the sella turcica, allowing for early identification of the medial wall and simplifying dissection. We support this technique with an anatomical analysis on cadaveric specimens and clarifying dissection images. CONCLUSION: Recognition and dissection of the dural unfolding of the floor of the sella turcica are "key points" that lower the risk and facilitate the MWCSR.

Safe Zones for Facial Fillers: Anatomical Study of SubSMAS Spaces in Asians.

The study "Spaces of the Face for Filler Procedures: Identification of subSMAS Spaces Based on Anatomical Study" explores the anatomy of facial spaces crucial for safe and effective filler injections. By delineating the subSMAS (sub-superficial musculoaponeurotic system) spaces, this research highlights how these virtual compartments, bordered by fat, muscles, fascia, and ligaments, facilitate independent muscle movement and reduce the risk of damaging critical structures. The thicker and more robust skin of East Asians necessitates deeper filler injections, emphasizing the significance of accurately identifying these spaces. A cadaver study with dyed gelatin validated the existence and characteristics of these subSMAS spaces, confirming their safety for filler procedures. Key spaces, such as the subgalea-frontalis, interfascial and temporalis, and prezygomatic spaces, were examined, illustrating safe zones for injections. The findings underscore the importance of anatomical knowledge for enhancing facial aesthetics while minimizing complications. This study serves as a guide for clinicians to perform precise and safe filler injections, providing a foundation for further research on the dynamic interactions of these spaces and long-term outcomes.

Anatomical Variants of the Origin of the Coronary Arteries: A Systematic Review and Meta-Analysis of Prevalence.

PURPOSE: The most common anomaly is an anomalous left coronary artery originating from the pulmonary artery. These variants can be different and depend on the location as well as how they present themselves in their anatomical distribution and their symptomatological relationship. For these reasons, this review aims to identify the variants of the coronary artery and how they are associated with different clinical conditions. METHODS: The databases Medline, Scopus, Web of Science, Google Scholar, CINAHL, and LILACS were researched until January 2024. Two authors independently performed the search, study selection, and data extraction. Methodological quality was evaluated using an assurance tool for anatomical studies (AQUA). Pooled prevalence was estimated using a random effects model. RESULTS: A total of 39 studies met the established selection criteria. In this study, 21 articles with a total of 578,868 subjects were included in the meta-analysis. The coronary artery origin variant was 1% (CI = 0.8-1.2%). For this third sample, the funnel plot graph showed an important asymmetry, with a p-value of 0.162, which is directly associated with this asymmetry. CONCLUSIONS: It is recommended that patients whose diagnosis was made incidentally and in the absence of symptoms undergo periodic controls to prevent future complications, including death. Finally, we believe that further studies could improve the anatomical, embryological, and physiological understanding of this variant in the heart.

Current Perspectives of Protein in Bone Tissue Engineering: Bone Structure, Ideal Scaffolds, Fabrication Techniques, Applications, Scopes, and Future Advances.

In view of their exceptional approach, excellent inherent biocompatibility and biodegradability properties, and interaction with the local extracellular matrix, protein-based polymers have received attention in bone tissue engineering, which is a multidisciplinary field that repairs and regenerates fractured bones. Bone is a multihierarchical complex structure, and it performs several essential biofunctions, including maintaining mineral balance and structural support and protecting soft organs. Protein-based polymers have gained interest in developing ideal scaffolds as emerging biomaterials for bone fractured healing and regeneration, and it is challenging to design ideal bone substitutes as perfect biomaterials. Several protein-based polymers, including collagen, keratin, gelatin, serum albumin, etc., are potential materials due to their inherent cytocompatibility, controlled biodegradability, high biofunctionalization, and tunable mechanical characteristics. While numerous studies have indicated the encouraging possibilities of proteins in BTE, there are still major challenges concerning their biodegradability, stability in physiological conditions, and continuous release of growth factors and bioactive molecules. Robust scaffolds derived from proteins can be used to replace broken or diseased bone with a biocompatible substitute; proteins, being biopolymers, provide excellent scaffolds for bone tissue engineering. Herein, recent developments in protein polymers for cutting-edge bone tissue engineering are addressed in this review within 3-5 years, with a focus on the significant challenges and future perspectives. The first section discusses the structural fundamentals of bone anatomy and ideal scaffolds, and the second section describes the fabrication techniques of scaffolds. The third section highlights the importance of proteins and their applications in BTE. Hence, the recent development of protein polymers for state-of-the-art bone tissue engineering has been discussed, highlighting the significant challenges and future perspectives.

MRI-based axis-referenced morphometric model corresponding to lamellar organization for assessing hippocampal atrophy in dementia.

Research on the local hippocampal atrophy for early detection of dementia has gained considerable attention. However, accurately quantifying subtle atrophy remains challenging in existing morphological methods due to the lack of consistent biological correspondence with the complex curving regions like the hippocampal head. Thereby, this article presents an innovative axis-referenced morphometric model (ARMM) that follows the anatomical lamellar organization of the hippocampus, which capture its precise and consistent longitudinal curving trajectory. Specifically, we establish an "axis-referenced coordinate system" based on a 7 T ex vivo hippocampal atlas following its entire curving longitudinal axis and orthogonal distributed lamellae. We then align individual hippocampi by deforming this template coordinate system to target spaces using boundary-guided diffeomorphic transformation, while ensuring that the lamellar vectors adhere to the constraint of medial-axis geometry. Finally, we measure local thickness and curvatures based on the coordinate system and boundary surface reconstructed from vector tips. The morphometric accuracy is evaluated by comparing reconstructed surfaces with those directly extracted from 7 T and 3 T MRI hippocampi. The results demonstrate that ARMM achieves the best performance, particularly in the curving head, surpassing the state-of-the-art morphological models. Additionally, morphological measurements from ARMM exhibit higher discriminatory power in distinguishing early Alzheimer's disease from mild cognitive impairment compared to volume-based measurements. Overall, the ARMM offers a precise morphometric assessment of hippocampal morphology on MR images, and sheds light on discovering potential image markers for neurodegeneration associated with hippocampal impairment.

A scarce combination of arterial variants: an occipital artery originating from the internal carotid artery associated with a linguofacial trunk.

The occipital artery (OA) typically originates from the external carotid artery (ECA). Variations of the ECA has been well described in the current literature, while the OA is a relatively stable vessel, and its variations are uncommon. In the current case report, an aberrant OA has been found coexisting with a linguofacial trunk (LFT) on the right hemineck of a 51-year-old male patient. The OA was identified originating from the cervical internal carotid artery (ICA) at the level of the second cervical vertebra (C2). On the ECA, the lingual and facial arteries were emanating in common, as LFT. The left hemineck of the patient was free of variations. The current coexistence of arterial variants has been reported only once previously; therefore, the current case corresponds to the second case in the English literature. The aberrant OA origin from the ICA has been estimated with a pooled prevalence of 0.37%, while the origin at the C2 level and from the anterior surface of the ICA corresponds to a very rare variation. Additionally, the LFT is one of the most common trunk that can be found on the ECA. Interventional radiologists and surgeons must be aware of common and uncommon variation to avoid iatrogenic lesion.

Evaluation of the mesenteric arterial vasculature by computed tomography angiography and its implications for colorectal cancer surgery.

Objective: To determine the branching patterns of the inferior mesenteric artery (IMA) and to describe the clinical applicability of computed tomography (CT) angiography in the evaluation of these vessels to facilitate the planning of colorectal cancer surgery. Materials and Methods: We included 100 patients who underwent CT angiography of the abdomen and pelvis. The branching patterns of the IMA were examined and classified as type 1 (bifurcated), including 1A (sigmoid and left colic arteries arising from a common trunk), 1B (sigmoid and superior rectal arteries arising from a common trunk) and 1C (sigmoid arteries arising from both trunks); type 2 (trifurcated); and type 3 (no left colic branch). Results: Among the 100 patients evaluated, we found the variant to be type 1A in 9%, type 1B in 47%, type 1C in 24%, type 2 in 16%, and type 3 in 4%. Conclusion: Preoperative CT angiography for evaluating the IMA branching pattern could inform decisions regarding the surgical approach to colorectal cancer.

Objetivo: Determinar os padrões de ramificação da artéria mesentérica inferior (AMI) e descrever a aplicabilidade clínica da angiografia por tomografia computadorizada na avaliação desses vasos na elaboração das estratégias pré-operatórias de cirurgia de câncer colorretal. Materiais e Métodos: Foram incluídos 100 pacientes submetidos a angiografia por tomografia computadorizada abdominal e pélvica. Os padrões de ramificação da AMI foram examinados e classificados como tipo 1 (bifurcado), incluindo 1A (artérias sigmoide e cólica esquerda originando-se de um tronco comum), 1B (artérias sigmoide e retal superior originando-se de um tronco comum) e 1C (artérias sigmoide originando-se de ambos os troncos); tipo 2 (trifurcado); e tipo 3 (sem ramo cólico esquerdo). Resultados: Do total de participantes incluídos no estudo, a variante do tipo 1A foi observada em 9%, a do tipo 1B em 47%, e a do tipo 1C em 24%. Com relação à variante tipo 2, esta foi observada em 16% dos pacientes, e a do tipo 3, em 4% dos casos.Conclusão O uso da angiografia por tomografia computadorizada pré-operatória para avaliar o padrão de ramificação da AMI pode ajudar a escolher a abordagem cirúrgica no câncer colorretal.