Abstract
Arachnoid (pacchionian) granulations are enlarged arachnoid villi, being extensions of the subarachnoid space that contain cerebrospinal fluid (CSF) internally. They serve as an important drainage route for CSF into the venous system. These outpouchings extend from the subarachnoid space through the dura mater into the dural sinuses (and occasionally into the calvarium). They may simulate dural sinus filling defects such as thrombus, stenosis, or occlusion. Studies have shown that they can be identified in most asymptomatic patients (60–90 %, based on imaging or autopsy) if a thin-section postcontrast MRI or MR venogram (MRV) is thoroughly inspected, and that they are often multiple. On contrast-enhanced CT, the frequency is lower, likely in the range of 25–33 %.
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McKinney, A.M. (2017). Arachnoid Granulations Within the Dural Sinuses. In: Atlas of Normal Imaging Variations of the Brain, Skull, and Craniocervical Vasculature . Springer, Cham. https://doi.org/10.1007/978-3-319-39790-0_41
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DOI: https://doi.org/10.1007/978-3-319-39790-0_41
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