Cerebral angiography

Indications

A cerebral DSACerebral digital subtraction angiography (DSA) is indicated in a variety of settings including:

• trauma

• investigationInvestigation and treatment of an aneurysm:

  • Aneurysm/s  

  • confirming brain deathVascular abnormalities

    • Arterio-venous malformations

    • studyArterio-venous fistula

    • Carotid cavernous fistula

    • Meningioma

  • Cerebral vasospasm

• Investigation of vascular abnormalities:

  • Reversible cerebral vasoconstriction syndrome

  •  Moya-moya

• Confirming brain death

Projections

Standard projections

• PA internal carotid artery

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

  • petrous ridge superimposed on supraorbital margin

  • include 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 entire skull vault

  • effectively demonstrates

    • ICA  cavernous portion

    • ICA  communicating segment (PCOM, Anterior choidal 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 entire skull vault. However, magnification can be employed if 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 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 baseline position for cross compression and visualisation of the ACOM

    • MCA M1 segment

• PA vertebral artery

  • petrous ridge positioned on supraorbital margin

  • effectively demonstrates

    • vertebral distal portion

    • basilar artery

    • SCA

    • 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 PA, the c-arm is angled cranially to demonstrate the PCA best in addition for 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 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