Background: High-resolution ultrasound of the tibial nerve has been used for screening of several neurologic disorders, but normative reference values of tibial nerve cross-sectional areas (CSA) have not been well established. Thus, the present meta-analysis was performed to generate normative estimates of tibial nerve CSA at various sites of the lower limb based on ultrasonography. Methods: Google Scholar, Scopus and PubMed were searched for potential studies. Studies were required to report tibial nerve CSA in healthy individuals to be included. A random-effect meta-analysis was performed to calculate tibial nerve CSA values. Subgroup and statistical analyses were performed to study covariates. Results: Forty-eight eligible articles consisting of 2695 limbs were included. The average tibial nerve CSA was found to be 10.9 mm² at the ankle (95% CI: 9.9–11.8) and should not exceed 11.8 mm² in healthy adults. At the popliteal fossa, the overall CSA was 21.7 mm² (95% CI: 17.5–25.8) in healthy adults. At both sites, the average tibial nerve CSA was significantly larger in adults than in children, and the differences by geographical region were not statistically significant. At the ankle, tibial nerve CSA increased with age and body mass index, while at the popliteal fossa it increased with age and weight. Conclusions: our findings indicate that the tibial nerve varied not only along its course but also among sub-variables. Establishing normal references values of tibial nerve CSA is helpful to differentiate healthy from diseased tibial nerves such as in diabetic peripheral neuropathy or tarsal tunnel syndrome.

Background and Objectives: Anatomical variations in the head, neck and chest are common, and are observed as occasional findings on computed tomography (CT). Although anatomical variations are mostly asymptomatic and do not cause any negative influence on the body function, they may jeopardize diagnosis and may be confused with pathological conditions. The presence of variations may also limit surgical access during tumor removal. The aim of this study was to investigate the prevalence of six anatomical variations—os acromiale, episternal ossicles, cervical rib, Stafne bone cavity, azygos lobe and tracheal bronchus—in an open-access computed tomography dataset obtained from oropharyngeal cancer patients. Materials and Methods: A total of 606 upper-chest and neck computed-tomography scans (79.4% male and 20.6% female) were retrospectively investigated. Sex difference was evaluated using the z-test for two proportions. Results: Os acromiale, episternal ossicles, cervical rib, Stafne bone cavity, azygos lobe, and tracheal bronchus were present in 3.1%, 2.2%, 0.2%, 0%, 0.3% and 0.5%, respectively, of all patients. Os acromiale was identified as meso-acromion in 86.6%, and as pre-acromion in 17.4%, of all acromia. Episternal ossicles were present unilaterally in 58.3%, and bilaterally in 41.7%, of all sterna. Only the cervical rib showed a sex difference in prevalence. Conclusions: awareness of these variations is important for radiologists interpreting head, neck and chest CTs; for example, those of oropharyngeal cancer patients. This study also illustrates the applicability of publicly available datasets in prevalence-based anatomical research. While most of the variations investigated in the present study are well-known, the episternal ossicles are not well explored, and need further investigation.

The increasing prevalence of cannabidiol (CBD) use during pregnancy raises concerns regarding its impact on fetal neurodevelopment. This study examined how the administration of CBD in ovo influences mortality rates, physical development, and the structural arrangement of the forebrain in avian embryos. Fertilized eggs were injected with 10 µM CBD or vehicle control into the yolk sac at Hamburger–Hamilton (HH) stages 7–8 (24 hours of incubation). Embryos were evaluated at Days 3, 6, and 13 using morphological, histological, and molecular analyses. Early exposure significantly reduced survival at Day 3 (79.3% vs. 93.8%, p = 0.041) and accelerated neural tube differentiation, coinciding with a 2.3-fold upregulation of Bone Morphogenetic Protein 4 (BMP-4) (p = 0.009). While survival rates showed a non-significant reduction by Day 6, transient growth retardation was observed. By Day 13, CBD-treated embryos exhibited distinct morphological alterations, including increased egg tooth length (p = 0.023) and brain weight (p = 0.007). Histological examination of the forebrain revealed narrowed ependymal zones, aberrant mesenchymal-like cell infiltration, and significantly reduced neurite extension. These findings suggest that early CBD exposure disrupts neurodevelopmental timing and forebrain architecture, potentially mediated through dysregulated BMP-4 signaling. Although embryos demonstrated somatic resilience, the persistent cellular and structural anomalies highlight the potential neuroteratogenic risks of CBD exposure during early embryogenesis.