Mca anatomy

middle cerebral anatomy

1. MCA Anatomy - Dr Dikpal

2. Introduction The MCA is the largest and most complex of the cerebral arteries The MCA arises as the larger of the two terminal branches of the internal carotid artery The diameter of the MCA at its origin ranges ( average, 3.9 mm), roughly twice that of the anterior cerebral artery

3. Its origin and course

4. Post medial

5. Segments M1 (sphenoidal), M2 (insular), M3 ( opercular ), M4 (cortical)

6. M1 segment Microneurosurgical and angiographic Prebifurcation and post bifurcation parts How to distinguish between early branches and M1

7. Branching pattern M1

8. Early branches Cortical Branches from main trunk proximal to MCA division types early temporal branches- more common early frontal branches

9. Perforating branches Lenticulostraite arteries - branches of MCA that enter anterior perforating substance (APS) origin from superior or posterosuperior MCA 3 groups : medial, intermediate and lateral MEDIAL : least constant, 1-5 branches from M1, enter medial APS INTERMEDIATE : constant, few branches dividing , atleast 1 major artery LATERAL : constant S shaped course, enter posterolateral part of APS

10. Cortical branches

11. Anomalies of MCA Rare compared to other intracranial arteries Main anomalies include duplication accessory fenestration

12. Anatomy of the Middle Cerebral Artery: Cortical Branches, Branching Pattern and Anomalies; Karen CILLIERS, Benedict John PAGE; DOI: 10.5137/1019-5149.JTN.18127-16.1

13. Angiographic Sylvian Point (ASP) It is the most medial point where the last cortical MCA branch (usually the angular artery) turns inferiorly to exit the sylvian fissure.( On AP view ) This point approximates the apex of the insula and represents the posterior limit of the lateral cerebral sulcus .

14. Sylvian triangle (angiographic) The superior insular line ( A line tangent to the tops of the insular loops ), Main MCA trunk ( forms the posterior inferior margin of the triangle) Most anterior branch of the ascending frontal complex ( forms the anterior border of the triangle)  It is seen in lateral view and serves as angiographic landmark for localizing supratentorial masses. 

15. Round shift = Frontal lesion anterior to coronal suture Square shift = Lesion behind foramen of Monro in lower half of hemisphere Distal shift = Posterior to coronal suture in upper half of hemisphere Proximal shift = Basifrontal lesion / anterior middle cranial fossa including anterior temporal lobe

16. Exposing MCA

17. Sylvian fissure