BACKGROUND: The aim of the study was to describe the comprehensive morphological and morphometric features of the foramina and canals at the base of the cranial cavity in Holstein cow using CT images.
METHODS: The study was performed on fourteen adult Holstein cow head cadavers. Images taken with MSCT were transferred to the DICOM Viewer program. The MPR and 3D reconstructive tools of the program were used to analyse the foramina and canals.
RESULTS: Although they varied in shape and size, foramina and canals were found bilaterally in all animals. It was observed that the orbitorotund foramen, jugular foramen and oval foramen had a canalicular structure, with the distance between the extra-intra cranial openings measured as 15.0 mm, 5.9 mm and 6.2 mm, respectively. The hypoglossal canal, which was found to be single in 43%, double in 50% and triple in 7% in each body half, was the canal with the most variation in number and shape. The orbitorotund foramen, a canal with an area of 180.6 mm² and a diameter of 18.1 × 12.4 mm is the widest at the skull base, while the optic canal is the narrowest and longest opening with an area of 33.4 mm², a diameter of 8.4 × 5.5 and a length of 17.5 mm.
CONCLUSIONS: This study shows that our knowledge of skull base morphometry in animals is extremely limited. Although the study was conducted on a limited number of materials, it may benefit both regional anatomy knowledge in terms of the data presented and veterinary anatomists, radiologists and clinicians in terms of methodology.

OBJECTIVE: The aim of this study was to find the prevalence of emissary veins and to compare the visibility of these emissary veins with the anatomic variations of the dural venous sinuses detected in magnetic resonance venography (MRV).
METHODS: All MR images of two hundred twenty patients were evaluated retrospectively. Posterior cranial fossa emissary veins diameter measurements were performed in the axial plane. The anatomic variations of the venous sinuses in MRVs of all patients were recorded. Accordingly, the presence of the emissary veins was compared with the dural venous sinus anatomic variations. p < 0.05 was considered statistically significant. An inter-observer reliability analysis was performed.
RESULTS: The prevalence of emissary veins in MRI was found in the right mastoid emissary vein (MEV) 82.7% and left MEV 81.4%. Occipital emissary vein (OEV) was present in 63 patients (28.6%) for the first radiologist (R1), and it was present in 61 patients (27.7%) for the second radiologist (R2) (K = 0.978). A statistically significant correlation was detected between the diameter of the left MEV and gender (p < 0.05) for both radiologists. There was a statistically significant difference between the left MEV and OEV and transverse sinus anatomic variations.
CONCLUSIONS: MR imaging is a noninvasive and irradiating imaging method for detecting posterior fossa major emissary veins, and we recommend using MR imaging for preoperative evaluation of posterior fossa major emissary veins and related dural venous sinuses.