Radiological anatomy of brain. Brief Description about anterior and posterior circulation of the brain and cerebral vascular territories.

1. BY DR NISHANT RAJ

2. INTRACRANIAL
CIRCULATION
ANTERIOR
CIRCULATION
POSTERIOR
CIRCULATION
INTRACRANIAL ICA + BRANCHES
ACA
MCA
ACoA
PCoA
VERTEBROBASILARTRUNK
PCA

3. INTERNAL CAROTID ARTERY

6. PETROUS SEGMENT
• BRANCHES:
• Vidian artery
• Caroticotympanic artery

7. LACERUM SEGMENT
•Extends from Petrous Apex
to Cavernous Sinus.
•Passes over foramen
lacerum.
•No Branches

8. CAVERNOUS SEGMENT
• Has 3 subsegments linked by 2
genua.
• Short posterior ascending vertical
segment.
• Longer horizontal segment
• Anterior vertical ascending segment
• BRANCHES:
• Meningohypophyseal trunk
• Inferolateral trunk

9. CLINOID SEGMENT
• Lies between proximal and
distal dural rings of cavernous
sinus.
• No major branches.

10. OPHTHALMIC SEGMENT
• Extends from distal dural ring
to just below PCoM origin.
• Branches:
• OphthalmicArtery
• Superior Hypophyseal artery

11. COMMUNICATING SEGMENT
• From below PCoA origin to terminal
ICA bifurcation intoACA and MCA.
• BRANCHES:
1. Anterior ChoroidalArtery.
2. PCoA

12. NORMAL ICAVARIANTS
•ABERRANT ICA
•PERSISTENT STAPEDIAL ARTERY
•EMBRYONIC CAROTID-BASILAR ANASTOMOSIS

13. ABERRANT ICA

14. PERSISTENT STAPEDIAL ARTERY

15. EMBRYONIC CAROTID BASILAR
ANASTOMOSIS

16. CIRCLE OFWILLIS

18. COMMONVARIANTS
hypoplasia of one or both PCOM
hypoplastic/absent A1 segment of ACA
absent or fenestrated ACOM
Origin of PCA from the ICA with absent/hypoplastic P1 segment (fetal
PCA)
infundibular dilatation of the PCOM origin ~10%

19. PCOM HYPOPLASIA

20. HYPOPLASTIC/ABSENT A1
SEGMENT

21. ABSENT/FENESTRATED ACOM

22. FETAL PCOM

23. ANTERIOR CEREBRAL ARTERY

24. • A1 (HORIZONTAL SEGMENT)
• A2 (VERTICAL SEGMENT)
• A3 (CALLOSAL SEGMENT

25. VASCULARTERRITORY

26. MIDDLE CEREBRAL ARTERY
• M1(HORIZONTAL SEGMENT)
• M2(INSULAR SEGMENT)
• M3(OPERCULARSEGMENT)
• M4(CORTICAL SEGMENTS)

27. VASCULARTERRITORY

28. POSTERIOR CEREBRAL ARTERY
• P1(PRE-COMMUNICATING
SEGMENT)
• P2(AMBIENT SEGMENT)
• P3(QUADRIGEMINAL
SEGMENT)
• P4(CALCARINE SEGMENT)

29. VASCULARTERRITORY

30. VERTEBRO-BASILAR
CIRCULATION
• V1(EXTRAOSSEUS
SEGMENT)
• V2(FORAMINAL SEGMENT)
• V3(EXTRASPINAL SEGMENT)
• V4(INTRADURAL SEGMENT)

31. CEREBRALVASCULARTERRITORIES