VASCULAR MALFORMATIONS GALLERY Flashcards
What are the parts of the AVM
Graphic depicts AVM nidus with intranidal aneurysm , feeding artery (“pedicle”) aneurysm , and enlarged draining veins
Dx?
NECT scan (upper left) and CTA images in a patient with spontaneous cerebellar hemorrhage demonstrate an underlying AVM . Approximately 15% of AVMs are infratentorial
Describe the classic MRI findings of AVM
Axial T1WI in a 32-yearold man with headache shows a classic wedge-shaped left parietal AVM with multiple serpentine “flow voids” .
A few linear foci of T1 shortening represent thrombosed vessels within the nidus. T2WI in the same patient nicely demonstrates the wedge of “flow voids” . The broad base toward the cortex with apex pointing toward the lateral ventricle is a typical configuration for
brain AVMs.
FLAIR findings of AVM
FLAIR scan demonstrates minimal hyperintensity within and around the AVM , suggesting small foci of gliotic brain.. T1 C+ scan shows some linear and serpentine areas of enhancement that are mostly in draining veins.
What is your dx?
DSA of selective internal carotid angiogram in a patient with cerebral proliferative angiopathy shows
innumerable dilated vascular spaces with no dominant feeding arteries
Describe the parts of the DAVF
Graphic depicts dAVF with thrombosed transverse sinus with multiple tiny arteriovenous in the
dural wall . Lesion is mostly supplied by transosseous feeders from the external carotid artery
What is your dx?
Contrast-enhanced MRA source image shows dural sinus thrombosis , multiple enhancing vascular channels characteristic of posterior fossa dAVF. . MRA in the same patient shows innumerable tiny feeding arteries supplying a dAVF at the transverse-sigmoid sinus junction. The sinus has partially recanalized , and the distal sigmoid sinus and jugular bulb are partially opacified
What is your dx?
Autopsy case of direct CCF with dissection of the cavernous sinus (CS) and adjacent structures shows
that the right CS is enlarged by numerous dilated vascular channels
What is shown?
Clinical photograph of a patient with a CCF shows numerous enlarged scleral vessels . 7-17. CECT
scan shows classic findings of CCF. The right cavernous sinus is enlarged , and the ipsilateral superior
ophthalmic vein is more than 4 times the size of the left superior ophthalmic vein
Describe the MRI
T2WI shows typical MR findings of CCF with an enlarged right cavernous sinus containing numerous abnormal “flow voids” . Lateral DSA in a case of direct CCF in a 21-year-old woman with multiple skull base fractures shows that the ICA narrows before terminating in a large venous pouch . High-pressure venous reflux into the superior and inferior ophthalmic veins and the sphenoparietal sinus is present.
What is shown?
Pial AVF with slightly enlarged ACA branches connecting to a venous varix , dilated cortical
draining vein .
Describe the draining vessels of the AVF
Coronal T1 C+ scan shows a pial AVF in the posterior fossa. A small cerebellar artery connects
directly to a venous pouch , which in turn drains into a subependymal vein near the fourth
ventricle.
What is shown?
Graphic illustrates vein of Galen malformation. Enlarged choroid arteries drain directly into
dilated median prosencephalic vein (MPV) , falcine sinus . Torcular herophili (venous sinus
confluence) is massively enlarged.
What is the dx?
CECT scan in a newborn demonstrates a massive VGAM draining into an enlarged falcine sinus
, causing obstructive hydrocephalus
What is shown?
CECT, CTA depict classic DVA in the left cerebellar hemisphere
Where do the veins collect?
T1 C+ scan shows a classic DVA with enlarged WM veins and a collector vein draining into the anterior aspect of the superior sagittal sinus. SWI scan shows the DVA and collector vein as hypointense structures clearly different in configuration from the normal cortical veins. A focal hemorrhage adjacent to the left frontal horn is secondary to a small cavernous malformation. DVAs are often
histologically mixed lesions.
Describe the medullary veins
3D SSD demonstrates a classic DVA with enlarged medullary veins draining into the collector vein
. The appearance resembles a “Medusa head,” “upside-down willow tree” or “umbrella.”
What is shown?
T2WI shows classic “popcorn ball” appearance with locules of blood in different stages of evolution
surrounded by hemosiderin rim
What type of Cavernoma is shown?
Zabramski type 1 CCM is illustrated. (Left) T1WI shows that the lesion is hyperintense and surrounded by a hypointense hemosiderin rim .
(Right) T2* GRE scan shows “blooming” hypointensity both around and within the lesion. Microscopic section from the resected specimen in the same case shows a blood-filled cavity surrounded by thin endothelium-lined vascular channels
What type of Cavernoma is shown?
T2WI in a patient with multiple cerebral cavernous malformations shows a large left frontal lesion
with a fluid-fluid level . Multiple other hypointense lesions are present . 7-42B. T2* SWI shows
innumerable “blooming black dots” characteristic of Zabramski type 4 CCM (punctate microhemorrhages).
T2* scans are much more sensitive than FSE T2WI in depicting field inhomogeneities
What is shown?
Series of images demonstrates classic findings of pontine capillary telangiectasia. Axial T1WI is normal. Axial T2WI in the same patient likewise shows no abnormality.
FLAIR scan shows faint patchy hyperintensity in the pons. T2* GRE scan shows susceptibility effect with grayish hypointensity in the mid pons
What is your dx?
T1 C+ scan shows the brush-like faint enhancement that is characteristic of capillary telangiectasia. 7-47F. DTI fiber tracking is normal. The transverse pontine fibers cross undisturbed through the lesion
This figure is characteristic of?
(Top) Axial and (bottom) coronal T1 C+ scans show that the lesion enhances in a brush-like fashion. A prominent central draining vein is present . Imaging findings are characteristic of capillary telangiectasia
A patient with a history of whole brain radiation 5 years earlier for a WHO grade III anaplastic astrocytoma developed seizures. T2* GRE scan shows multiple “blooming” hypointensities.
T2* SWI scan in the same patient shows innumerable punctate microhemorrhages. Findings are
consistent with radiation-induced capillary telangiectasias
By convention, the extracranial ICA—which
normally has no named branches in the neck—is designated as the________
C1 (cervical) segment
C2 (PETROUS) ICA SEGMENT. The C2 (petrous) segment is contained within the carotid canal of the temporal bone
and is L-shaped (8-1). As it enters the skull at the exocranial opening of the carotid canal, the ICA lies just in front
of the______
internal jugular vein
What are the branches of C2
The vidian artery, also known as the artery of the pterygoid canal, anastomoses with branches of the external carotid artery (ECA). The caroticotympanic artery is a small ICA branch that supplies the middle ear
The _________is a short segment that lies just above the foramen lacerum and extends from the petrous apex to the cavernous sinus
C3 (lacerum) segment
What are the parts of the C4 segment
In order, these are (1) a short posterior ascending (vertical) segment, (2) the posterior genu, (3) a longer horizontal segment, (4) an anterior genu, and (5) an anterior vertical ascending (subclinoid) segment.
What are the branches of the C4 segment?
The meningohypophyseal trunk arises from the posterior genu, supplying the pituitary gland, tentorium, and clival dura.
The inferolateral trunk (ILT) arises from the lateral aspect of the intracavernous ICA and supplies cranial nerves and CS dura
The __________is a short interdural segment that lies between the proximal and distal dural rings of the CS. It terminates as the ICA exits the CS and enters the cranial cavity adjacent to the anterior clinoid process
C5 (clinoid) segment
The ________is the first ICA segment that lies wholly within the subarachnoid space
C6 (ophthalmic) segment
What are the branches of the C6 segment?
The ophthalmic artery (OA) arises from the anterosuperior aspect of the ICA, then passes anteriorly through the optic canal together with CN II. The OA has extensive anastomoses with ECA branches in and around the orbit and lacrimal gland.
The superior hypophyseal artery arises from the posterior aspect of the C6 ICA segment and supplies the anterior pituitary lobe (adenohypophysis) and infundibular
stalk as well as the optic chiasm.
________is the last ICA segment and extends from just below the PCoA origin to the terminal ICA bifurcation into the ACA and MCA. As it courses posterosuperiorly,
the ICA passes between the optic and oculomotor nerves
The C7 (communicating) segment
What are the branches of C7
The PCoA joins the anterior to the posterior circulation. A number of perforating arteries arise from the PCoA to supply the basal brain structures including the
hypothalamus.
The anterior choroidal artery (AChA) arises one or two millimeters above the PCoA and initially courses
posteromedially, then turns laterally in the suprasellar cistern to enter the choroidal fissure of the temporal horn.
What are the three ICA vascular anomalies?
Three important ICA vascular anomalies must be recognized on imaging studies: An aberrant ICA (AbICA), a
persistent stapedial artery, and an embryonic carotidbasilar anastomosis
A ____________is the most common COW
variant and occurs in one-quarter to onethird of all cases
hypoplastic or absent PCoA
The ___________also termed the horizontal or A1 segment, extends medially over the optic chiasm and nerves to the midline where it is joined to the contralateral ACA by the anterior communicating artery (ACoA).
first ACA segment,
Branches of the A1 segment
The medial lenticulostriate arteries pass superiorly through the anterior perforated substance to supply the medial basal ganglia.
The recurrent artery of Heubner arises from the distal A1 or proximal A2 ACA segment and curves
The _________segment courses superiorly in the interhemispheric fissure, extending from the A1-ACoA junction to the corpus callosum rostrum
A2 or vertical ACA
The A2 segment has two cortical branches, the _______ and ___________that supply the undersurface and inferomedial aspect
of the frontal lobe.
orbitofrontal and frontopolar arteries,
The A3 ACA segment curves anteriorly around the corpus callosum genu, then divides into the two terminal ACA branches, the_______ and ________
pericallosal and callosomarginal arteries
Two uncommon but important ACA anomalies:
An infraoptic A1 occurs when the horizontal segment passes below (not above) the optic nerve. An infraoptic A1 is associated with a highprevalence (40%) of aneurysms.
A single midline or azygous ACA is seen with the holoprosencephaly spectrum.
The most important branches of the M1 segment
The lateral lenticulostriate arteries supply the lateral putamen, caudate nucleus, and external capsule The anterior temporal artery supplies the tip of the temporal lobe.
The post-bifurcation MCA trunks turn posterosuperiorly in the sylvian fissure, following a gentle curve (the genu or “knee” of the MCA)
What segment?
M2 (INSULAR) SEGMENTS
The MCA branches loop at or near the top of the sylvian fissure, then course laterally under the parts (“opercula”) of the frontal, parietal, and temporal lobes that hang over and enclose the sylvian fissure.
It has 3 segments
M3 (OPERCULAR) SEGMENTS
Where is the P1 segment and what are its branches?
The P1 segment lies above the oculomotor nerve (CN III) and has perforating branches (the posterior thalamoperforating arteries) that course posterosuperiorly in the interpeduncular fossa to enter the undersurface of the midbrain.
Where is the P2 segment located?
The P2 segment extends from the P1-PCoA junction, running in the ambient
(perimesencephalic) cistern as it sweeps posterolaterally around the midbrain. The P2 segment lies above the
tentorium and the cisternal segment of the trochlear nerve (CN IV