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:
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diagnosis and treatment of:
acute ischemic stroke
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vascular abnormalities 1
cerebral vasospasm post subarachnoid hemorrhage
meningioma (preoperative embolization)
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investigation of:
confirming brain death
Projections
Standard projections
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posteroanterior internal carotid artery
projects middle cerebral artery away from bony landmarks, minimizing beam hardening artifacts
petrous ridge superimposed on supraorbital margin
include the entire skull vault
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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
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lateral internal carotid artery
include the entire skull vault
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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
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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°
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effectively demonstrates
ICA distal bifurcation
ACA A1 segment
ACA occasionally for ACOM
MCA trifurcation of M1/M2 segments
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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°
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effectively demonstrates
MCA occasionally trifurcation of M1/M2 segments
ACA occasionally for ACOM
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cross compression projection internal carotid
petrous ridge positioned on infraorbital margin
no (RAO/LAO) obliquity
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effectively demonstrates
ICA distal bifurcation
ACA A1 segment
ACOM provides a baseline position for cross compression and visualization of the ACOM
MCA M1 segment
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posteroanterior vertebral artery
petrous ridge positioned on supraorbital margin
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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
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lateral vertebral artery
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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
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Additional positioning notes for the vertebral artery
from the baseline vertebral posteroanterior, the c-arm is angled cranially to demonstrate the PCA best in addition to demonstrating the thalamoperforating vessels
basilar artery is foreshortened in Towne's view 2.
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 minimize movement
head positioned without rotation
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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