Anatomic relationship between arachnoid granulations in the transverse sinus and the termination of the vein of Labbe:: an angiographic study

We studied the anatomic relationship between arachnoid granulations in the transverse sinus and the termination of the vein of Labbe in 57 consecutive angiograms. Patients with pathology in intracranial venous structures or with inadequate image quality of the venous system were excluded. Arachnoid granulations were found in 12 of the 57 patients (21.1%), always at the junction of the vein of Labbe and the transverse sinus; the vein of Labbe was present in 55 patients (96.5 %), most often without associated arachnoid granulations; the latter, however, were not observed in the absence of a vein of Labbe. This study confirms the close, constant anatomic relationship between arachnoid granulations in the transverse sinus and the termination of the vein of Labbe. This observation may help to differentiate arachnoid granulations from pathologic conditions involving the transverse sinus such as dural sinus thrombosis. The constant character of this relationship suggests a developmental role of afferent veins in the formation of arachnoid granulations.