The accessory renal arteries (ARAs) are a well‐described variant of the renal vasculature with clinical implications for radiologists, surgeons, and clinicians. The aim of the present systematic review with meta‐analysis was to estimate the pooled prevalence of ARAs, including their variant number, origin, and termination, and to highlight symmetrical and asymmetrical morphological patterns. The systematic review used four online databases in accordance with PRISMA 2020 and Evidence‐based Anatomy Workgroup guidelines. R programming software was used for the statistical meta‐analysis. A total of 111 studies were considered eligible for our initial aim. The typical renal artery (RA) anatomy (a single bilateral vessel) was identified in 78.92%; the overall ARA prevalence was estimated at a pooled prevalence of 21.10%. The estimated pooled prevalence of one, two, three, and four ARAs were 18.67%, 1.80%, 0.01%, and <0.01%. The ARAs have been the subject of extensive research owing to their clinical importance, including in kidney transplantation surgery and resistant hypertension therapy. Knowledge of the typical and variant anatomy of RAs is essential for anatomists, radiologists, surgeons, and clinicians in order to avoid misunderstanding, complications, and iatrogenic injury.

Background: Sex estimation has been extensively investigated due to its importance for forensic science. Several anatomical structures of the human body have been used for this process. The human skull has important landmarks that can serve as reliable sex estimation predictors. Methods: In this study, orbital measurements from 92 dried skulls, comprising 35 males and 57 females, were utilized to develop a machine-learning-based classifier for sex estimation with potential applications in forensic science. The parameters evaluated included optic foramen height (OFH), optic foramen width (OFW), optic canal height (OCH), optic canal width (OCW), intraorbital distance (IOD), extraorbital distance (EOD), orbit height (OH), and orbit width (OW). Results: A Random Forest classifier was employed to analyze the data, achieving an overall test accuracy of 0.68. The model demonstrated a precision of 0.65, indicating a moderate level of false positives. The recall was 0.70, reflecting that 70% of the positive cases were correctly identified. The F1 score was calculated at 0.675, suggesting a balanced performance between precision and recall. The area under the curve (ROC AUC) score was also 0.72, indicating that the model can distinguish between classes. The most important features in the best subset were OW (0.2429), IOD (0.2059), EOD (0.1927), OFH (0.1798), and OFW (0.1787), highlighting their significant contributions to the model’s predictions. Conclusions: These findings suggest that orbital measurements could potentially serve as reliable predictors for automated sex estimation, contributing to advancements in forensic identification techniques

Background: The anterior cerebral artery (ACA), a critical component of the cerebral arterial circle, exhibits substantial morphological variability. While previous studies have explored ACA morphology using cadaveric and imaging methods, a comprehensive meta-analysis incorporating the latest evidence is lacking. Methods: Following current guidelines, a systematic review and meta-analysis were performed across four major databases, supplemented by the gray literature and targeted journal searches. Ninety-nine studies, encompassing 85,316 patients, met the inclusion criteria. Statistical analyses were conducted using R, applying random effects models to estimate pooled prevalence and morphometric parameters. Results: The pooled prevalence of typical ACA morphology was 93.75%, whereas variants were noted in 6.25% of cases. The predominant variation identified was the accessory ACA (aACA) (1.99%), followed by unilateral absence of the A1 segment (1.78%), with the latter being more frequently recognized in imaging studies (p < 0.0001). Rare variants encompassed azygos ACA (azACA) (0.22%), fenestrated ACA (fACA) (0.02%), and bihemispheric ACA (bACA) (0.02%). The mean diameter and length of the A1 segment were measured at 2.10 mm and 14.24 mm, respectively. Hypoplasia of the A1 segment (<1 mm diameter) was recorded in 3.15% of cases. The influences of imaging modality, laterality, and population distribution on prevalence estimates were minimal. No significant publication bias was detected. Conclusions: Although infrequent, variants of the ACA possess significant clinical importance attributable to their correlation with aneurysm formation and the impairment of collateral circulation. The aACA and the absence of the A1 segment emerged as the most common variations. This meta-analysis presents an updated and high-quality synthesis of ACA morphology, serving as a valuable reference for clinicians and anatomists.

Background: The arcuate foramen (AF), an osseous foramen, is probably formatted from the ossification of the posterior atlanto-occipital membrane. When this morphologically ossified variant exists, it encloses the vertebral artery (VA) third segment (V3). This close relationship may cause compression to the VA with concomitant vertebrobasilar insufficiency, vertigo, headaches, or neck pain. In the published literature, no studies investigate the abovementioned potential compression pattern. The present study examines the AF ossification pattern (complete or partial type) and the variable VA diameter at the atlantal part (V3), concluding a potential risk for VA compression after correlating the relative diameters (AF and VA diameters). Materials and Methods: One hundred and fifty dried first cervical vertebrae (atlases) and one hundred fifty computed tomography (CT) scans were obtained for the present study. The presence of a complete or incomplete AF was evaluated, and when present, its diameter was measured. To correlate these findings with the vessel, 50 computed tomography angiographies (without AF presence) were obtained to measure the V3 segment diameter. Results: Out of the total 600 (N = 600) sides, 111 sides had incomplete AF (18.2%), and 67 sides had complete AF (11.1%). The AF mean diameter was 6.41 (1.12) mm. The diameter of the V3 segment ranged between 5.0 and 6.0 mm; therefore, three morphological stenosis patterns were identified. A low risk of compression (over 6.0 mm) was identified in 61.2% (N = 109 sides), a moderate risk (between 5.0–6.0 mm) was observed in 29.2% (N = 52 sides), and a high risk (under 5.0 mm) was recorded in 9.6% (N = 17 sides). There was no statistically significant correlation regarding sexes and age for the potential compression patterns. Conclusions: The present study revealed the morphological stenosis pattern of the AF to the V3 segment. The variation had a high risk of compression to the vessel in 9.6% of sides, indicating that it is not infrequent. Knowledge of these details is essential for clinicians when investigating vertebrobasilar insufficiency.

Background: The caroticoclinoid bar (CCB) or caroticoclinoid foramen (CCF) represents a well-described ossified variant of the skull base. It corresponds to an osseous bridge (resulting after homonymous ligament ossification) between the anterior and middle clinoid processes (ACPs and MCPs) surrounding the internal carotid artery (ICA)’s cavernous segment. Although extensive research has been performed on this clinically significant entity, only a few studies have been conducted on its effect on the ICA. The current study on dried skulls, using computed tomography (CT) and computed tomography angiography (CTA) scans, aimed to investigate the CCB’s presence and potential morphological stenosis patterns. Methods: One hundred (100) dried adult skulls and one hundred sixty (160) skulls from CT scans of patients were obtained (a total of 520 observations). To further calculate the ICA diameter (at the ACP-MCP region) and correlate the resulting dimeters with all potential morphological stenosis patterns of the CCB, thirty (30) CTAs of patients free of the variant were selected. Results: Concerning the osseous pattern morphology, of the total of 520 sides, the CCB was identified in 17.1%, the complete variant (creating a caroticoclinoid foramen-CCF) was calculated in 11.5%, and the incomplete one was calculated in 5.6%. No side, sex, or age impact was identified for the CCB presence. Concerning the ICA dimensions, its diameter was calculated to be between 4 and 5 mm. Thus, we observed three morphological stenosis patterns of the CCF. A low-risk pattern of stenosis (>5 mm diameter) was observed in 40 CCFs (44.9%), an intermediate risk of stenosis (4–5 mm diameter) in 38 CCFs (38.2%), and a high risk of stenosis (<4 mm diameter) was depicted in 15 CCFs (16.8%). Conclusions: In the present study, we investigated the CCF presence and potential morphological stenosis patterns by calculating and correlating the ICA diameter. In 16.8% of the current sample with CCFs (irrespective of their morphology), we observed that the ICA is probably at a high risk of compression. Radiologists and neurosurgeons intervening in the area should preoperatively diagnose the possibility of ICA compression in this area.