Cerebral angiography

Cerebral angiography is an interventional procedure for the diagnosis and/or treatment of intracranial pathology.

Indications

Cerebral digital subtraction angiography (DSA) is indicated in a variety of settings including:

• diagnosis and treatment of:

  • aneurysms ¹

  • acute ischaemic stroke

  • vascular abnormalities ¹

    • arteriovenous malformation

    • arteriovenous fistula

      • caroticocavernous fistula

  • cerebral vasospasm post subarachnoid haemorrhage

  • meningioma (preoperative embolisation)

• investigation of:

  • reversible cerebral vasoconstriction syndrome

  • moya-moya syndrome

• confirming brain death

Projections

Standard projections

• PAposteroanterior internal carotid artery

  • projects middle cerebral artery away from bony landmarks, minimising beam hardening artifacts

  • petrous ridge superimposed on supraorbital margin

  • include the entire skull vault

  • conclusively demonstrates

    • ICA lacerum portion

    • ICA distal bifurcation

    • ACA A1 segment

    • MCA M1 segment (including lenticulostriate vessels)

    • confluence of sinuses

    • transverse sinus

    • sigmoid sinus

    • intracavernous sinus

• lateral internal carotid artery

  • include the entire skull vault

  • effectively demonstrates

    • ICA cavernous portion

    • ICA communicating segment (PCOM, anterior choroidal artery)

    • ACA A2 segments

    • MCA M3 segments

    • ophthalmic artery

    • superior and Inferior sagittal sinuses

    • internal cerebral veins

    • basal vein of Rosenthal

    • great vein of Galen

    • straight sinus

    • cavernous sinus

    • inferior petrosal sinus

• transorbital oblique internal carotid

  • petrous ridge positioned on infraorbital margin

  • include the entire skull vault. However, magnification can be employed if the indication is specifically for an intracranial aneurysm

  • ipsilateral obliquity, 30°

  • effectively demonstrates

    • ICA distal bifurcation

    • ACA A1 segment

    • ACA occasionally for ACOM

    • MCA trifurcation of M1/M2 segments

• reverse transorbital oblique internal carotid

  • petrous ridge positioned on infraorbital margin

  • include the entire skull vault; however, magnification can be employed if the indication is specifically for an intracranial aneurysm

  • contralateral obliquity 30°

  • effectively demonstrates

    • MCA occasionally trifurcation of M1/M2 segments

    • ACA occasionally for ACOM    

• cross compression projection internal carotid

  • petrous ridge positioned on infraorbital margin

  • no (RAO/LAO) obliquity

  • effectively demonstrates

    • ICA distal bifurcation

    • ACA A1 segment

    • ACOM provides a baseline position for cross compression and visualisation of the ACOM

    • MCA M1 segment

• PAposteroanterior vertebral artery

  • petrous ridge positioned on supraorbital margin

  • effectively demonstrates

    • vertebral distal portion

    • basilar artery

    • superior cerebellar artery (SCA)

    • anterior inferior cerebellar artery (AICA)

    • superior sagittal sinus

    • confluence of sinuses

    • transverse sinus

    • sigmoid sinus

• lateral vertebral artery

  • effectively demonstrates

    • vertebral artery distal portion

    • basilar artery (excluding basilar tip)

    • PCOM

    • PCA - posterior choroidal artery

    • superior and inferior sagittal sinuses

    • internal cerebral veins

    • basal vein of Rosenthal

    • great vein of Galen

    • straight sinus

Additional positioning notes for the vertebral artery

• from the baseline vertebral PAposteroanterior, the c-arm is angled cranially to demonstrate the PCA best in addition to demonstrating the thalamoperforating vessels

• caudal tilt (Water's projection) will better demonstrate the basilar artery without foreshortening.

• PICA origins best demonstrated in 45° ipsilateral obliquity

General patient positioning

• patient supine, head supported in a radiolucent head holder or curved sponge

• strap across the patient's head to minimise movement

• head positioned without rotation

• head tilt (radiographic baseline) determined by patient comfort

  • the patient should not be forced into an uncomfortable head tilt

  • adjustments made for head tilt by craniocaudally c-arm angulation