Contrast-enhanced Reformatted MR Images for Preoperative Assessment of the Bridging Veins of the Skull Base

Abstract

Magnetic resonance (MR) venography and computed tomographic (CT) venography are suited for displaying the convexity veins that drain the medial and lateral surfaces of the brain hemispheres. However, such is not the case for the bridging veins of the skull base. Technical factors prevent contrast material-enhanced MR or CT images obtained in standard axial, coronal, and sagittal planes from fully displaying the curved pathways of these clinically important venous structures. This limitation can be overcome by using a reconstruction technique that depicts these venous structures and their interconnections. Curved and multiplanar reformatted images that distill the important venous features often require knowledgeable manipulation of source images by an operator who is familiar with numerous venous variants and their surgical implications. The normal anatomy of the draining veins is detailed-anatomy that radiologists must master before they can show the surgeon the important venous anatomy that is often missing at standard imaging; this information will foster better communication between radiologists and their surgical colleagues. As a practical matter, the skull base veins are arbitrarily subdivided into those that are at greatest risk with the pterional approach and the subtemporal approach, respectively. These approaches can be expanded to define connections between the superficial venous system and the other valveless venous networks that drain the deep portions of the cerebral hemisphere, the scalp, face, muscles of the neck, diploë of the skull, and meninges. As radiologists gain experience, their image interpretations should mature beyond simple analysis of the primary hemodynamic changes induced by intraoperative sacrifice or injury.

Anatomical Configurations of Dominant Anastomotic Veins of the Superficial Cortical Venous System

“…The occurrence of the SSV in the present study is lower than that reported by Kawamata et al who reported a 99.2% presence in the left hemisphere and 95.1% in the right cerebral hemisphere 20 . Wangaryattawanich et al stated that the SSV may be absent in 9.0-10.0% of individuals; this statement is corroborated by the study conducted by Kazumata et al, who reported an absent or hypoplastic SSV in 10.0% of the sample 12,21 . In the absence of the SSV, the territory is drained by the deep system of cortical veins, or the adjacent AV 12,22 .…”

“…The largest anastomotic channel connecting the SSV and transverse sinus is the VL 11,12 . The VL originates in the posterior aspect of the lateral ssure and courses obliquely over the occipitotemporal sulcus, as well as the inferolateral aspect of the temporal lobe, to project posteroinferiorly into the transverse sinus 9,12 . The VT is the largest vein that crosses the lateral surface of the frontal or parietal lobes between the SSV and superior sagittal sinus 5,8 .…”

Tortuosity of superior cerebral veins: Comparative magnetic resonance imaging morphometrics in normal subjects and arteriovenous malformation patients

“…The superior cerebral veins (SCVs, TA code A12.3.06.003) are superficial veins lying on the surface of the cerebral cortex, draining mainly into several groups of cortical bridging veins (Kiliç & Akakin, 2008). The superior sagittal sinus (SSS) receives many such veins mainly from the superior part of the medial and lateral surfaces of the frontal, parietal, and occipital lobes (Mortazavi et al, 2013; O'Connell, 1934; Wangaryattawanich et al, 2016). The SCVs are key vascular tributaries within the intracranial venous system because they drain blood into the dural sinuses and, subsequently, into the internal jugular veins for return to the central circulation (Mortazavi et al, 2013).…”

“…The superior cerebral veins (SCVs, TA code A12.3.06.003) are superficial veins lying on the surface of the cerebral cortex, draining mainly into several groups of cortical bridging veins (Kiliç & Akakin, 2008). The superior sagittal sinus (SSS) receives many such veins mainly from the superior part of the medial and lateral surfaces of the frontal, parietal, and occipital lobes (Mortazavi et al, 2013;O'Connell, 1934;Wangaryattawanich et al, 2016).…”

Three‐Dimensional Angles of Confluence of Cortical Bridging Veins and the Superior Sagittal Sinus on MR Venography

“…Superficial veins lie on the surface of the cerebral cortex and drain mainly into several groups of cortical bridging veins (CBVs). The superior sagittal sinus (SSS) receives many such CBVs mainly from the superior part of the medial and lateral surfaces of the frontal, parietal, and occipital lobes (O'Connell, ; Mortazavi et al, ; Wangaryattawanich et al, ).…”