Abstract: Objective To further improve the morphological materials of AGs by microdissection, histology and CT, we observed the arachnoid granulations (AGs) in middle cranial fossa. Methods Thirty-three adult cadaveric heads were used for microsurgical dissection; Histological sections of AG specimens from 3 cadaver heads were examined. Forty patients who had both normal conventional brain CT and computed tomographic venography (CTV) were retrospectively reviewed. Results In middle cranial fossa the AGs occur in the following situations in order of frequency: the middle meningeal sinus, sphenoparietal sinus, lateral foramen rotundum and cavernous sinus. AGs usually show round, oval in shape and irregular in shape. AGs can be divided into individual type and leaflet type under light microscope. The numbers of AGs were observed by microanatomy and CTV were 8.72 and 3.52 respectively. The AGs of cavernous sinus was not localized precisely on CTV. Conclusion Study of the AGs in the middle cranial fossa systematically and comprehensively enriches anatomy and image knowledge. It is helpful in neurosurgical planning and choosing operalion procedure to avoid postoperative complications.

Key words: Middle cranial fossa, Arachnoid granulations, Microanatomy, Computed tomographic venography, Human