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Objective: The present study describes a rare anatomical variation of the anterior jugular vein (AJV) and discusses its clinical relevance., Methods: A head and neck specimen fixed in 10% formaldehyde from a 42-year-old female cadaver was submitted to angio technique with pre-vulcanized latex and water-soluble ink. During a routine dissection for the discipline of topographic anatomy, the presence of an arcuate AJV was detected in the anterior triangle of the neck., Results: An arcuate AJV was formed by the confluence of the submental and facial veins in the left submandibular region, which presented a complex network of anastomoses superficially to the left submandibular gland. After its origin, this vessel curved to the right at the level of the laryngeal prominence and followed the medial border of the right sternohyoid muscle to flow into the right AJV. In this topography, the arcuate AJV was located between the sternocleidomastoid muscle's anterior margin and the thyroid gland's right lobe. The presence of anastomoses between the two AJVs communicating the submandibular triangles was not detected., Conclusion: The arcuate AJV is a relevant anatomical variant in the superficial venous drainage of the neck that should be known by head and neck surgeons and radiologists to avoid surgical iatrogenic events., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Objective: To analyze the anatomical changes of the IV ventricle and cisterna magna in the Chiari malformation I (CMI) and basilar invagination (type B)., Methods: This is a controlled study with 161 exams of magnetic resonance imaging (MRI) of adults grouped into control (n = 37), basilar invagination (BI; n = 31), Chiari malformation I (CMI; n = 37), and CMI+BI (n = 56). The MRIs were analyzed using the visualization software Osirix (Pixmeo, Bernex, Geneva, version 3.8.2). The morphometric variables were: distance from the obex to the McRae line; length of the IV ventricle floor; and the area and volume of the cisterna magna. The univariate ANOVA followed by Tukey's post-hoc test was applied to evaluate the difference between the groups. The difference between sexes was evaluated by the t test for each group., Results: Alterations in the cisterna magna and IV ventricle were more evident only in the CMI and CMI+BI groups. For both sexes, the CMI and CMI+BI groups showed: a reduction in the CSF space (P < 0.001), cisterna magna with volume reduction (P < 0.001), low position of the obex (P < 0.001), and IV ventricle more elongated (male P = 0.007 and female P < 0.001). The BI group had no significant change in the analysis by sex., Conclusions: The CMI (isolated and associated with BI) showed a low obex position and elongation of the IV ventricle due to traction towards the spinal canal. The reduction of cisterna magna volume added to the occupation of the cerebellar tonsils can impact in the cerebrospinal fluid dynamics. The BI when isolated was not related to alterations in the parameters of cerebrospinal fluid spaces studied., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Objective: The present study aims to perform a reproducibility study of the clivus-canal angle (CCA), Welcker's basal angle (WBA), and the distance from the odontoid process to Chamberlain's line (DOCL) on magnetic resonance imaging (MRI)., Materials and Methods: Two medical students and two radiologists respectively evaluated 100 and 50 consecutive MRI scans of adult skulls, selected randomly. Each examiner, working independently and blinded to the previous results, performed readings for each patient on two different occasions. Measurements were performed in T1-weighted sequences acquired in the midsagittal plane. The levels of intraobserver reproducibility and interobserver agreement were evaluated by calculating the intraclass correlation coefficients (ICCs) and the corresponding 95% confidence intervals., Results: The mean values obtained by the examiners were 150º for the CCA, 130º for the WBA, and 2.5 mm for the DOCL. The ICC for interobserver agreement was 0.980, 0.935, and 0.967, for the CCA, WBA, and DOCL, respectively, for the students, compared with 0.977, 0.941, and 0.982, respectively, for the radiologists, and 0.980, 0.992, and 0.990, respectively, for all of the examiners together. In the analysis of intraobserver agreement, the ICC ranged from 0.929 to 0.959 for the CCA, from 0.918 to 0.964 for the WBA, and from 0.918 to 0.981 for the DOCL., Conclusion: The measurement of the CCA, WBA, and DOCL appears to show excellent intraobserver reproducibility and interobserver agreement on MRI.