Table 2:

Anatomic and angiographic findings

No.	Site	Location	Drainage	Grade^a	Arterial Feeders
1	Falx cerebelli	Midline	Infratentorially	IV	Meningohypophyseal trunk, ADS, SCA
2^b	Falx cerebelli	Midline	Infra- and supratentorially	IV	Occipital, middle meningeal, posterior meningeal arteries, meningohypophyseal trunk, SCA
3	Falx cerebelli	Midline	Infratentorially	IV	Occipital, middle meningeal, posterior meningeal arteries
4	Torcular	Midline	Supra- and infratentorially	II a + b	Occipital, middle meningeal, posterior meningeal, ascending pharyngeal, arteries, meningohypophyseal trunk, vertebral artery branches
5	Falx cerebelli	Midline	Infratentorially	IV	PICA, posterior meningeal artery
6	Petrotentorial right	Right	Infratentorially	IV	Middle meningeal, ascending pharyngeal arteries, meningohypophyseal trunk, AICA
7	Torcular	Midline	Supra- and infratentorially	II a + b	Occipital, middle meningeal arteries, ADS, SCA
8	Torcular	Midline	Infra- and supratentorially	IV	Occipital, posterior meningeal arteries, meningohypophyseal trunk, ADS, SCA vertebral artery branches
9	Falx cerebelli	Midline	Infratentorially	IV	Occipital middle meningeal, falcine arteries
10	Falx cerebelli	Midline	Infratentorially	III	Vertebral artery branches, PICA, SCA
11	Falx cerebelli	Midline	Infratentorially	IV	Occipital, middle meningeal, posterior meningeal arteries, PICA, ADS
12	Petrotentorial left	Left	Infra- and supratentorially	II a+ b	Occipital, middle meningeal, falcine, ascending pharyngeal arteries, meningohypophyseal trunk, inferolateral trunk, AICA
13	Torcular	Midline	Supra- and infratentorially	IV	Occipital, middle meningeal, posterior meningeal arteries, meningohypophyseal trunk

↵a According to Cognard et al.²⁰
↵b Previous surgery.