Nontraumatic Hemorrhage and Vascular Lesions Flashcards
What are the 4 segments of the aorta?
The ascending aorta, transverse aorta (mostly consisting of the aortic arch), aortic isthmus, and descending aorta.
The “classic” AA with three “great vessels” originating separately from the arch is seen in 80% of cases. In 10-25%of cases, the left CCA shares a common V-shaped origin with the BCT (commonly referred to as a_______
“bovine arch,” a misnomer as this configuration bears no resemblance to the AA branching pattern seen in ruminants).
Three thoracic aorta “lumps and bumps” are normal anatomic variants that should not be mistaken for pathology.
The __________is a narrowed segment just distal to the left SCA and proximal to the site of the fetal ductus
arteriosis.
An _______is a circumferential bulge in the aorta just beyond the ductus. Both the aortic isthmus and spindle typically disappear after two postnatal months but can persist into adulthood.
A _______is a focal bulge along the anteromedial aspect of theaortic isthmus and is seen in 10% of adults.
aortic isthmus
aortic spindle
ductus diverticulum
The most common anomaly of the aortic arch?
The most common congenital arch anomaly—
seen in 0.5-1.0% of cases—is a left AA with an aberrant right SCA
Where does an abberant SCA usually arise?
the aberrant right SCA arises from a dilated, diverticulum-like structure (Kommerell diverticulum)
a _________branching is strongly associated with cyanotic congenital heart disease (98% prevalence).
right AA with mirror image
The ___________provide the major blood supply to the face and cerebral hemispheres. It course superiorly, anteromedial to the internal jugular veins.
They terminate at about the C3-C4 or C4-C5
level by dividing into the internal and external carotid arteries
common carotid arteries (CCAs)
The cervical internal carotid artery is entirely extracranial and is designated as the C1 segment.
In 90% of cases, the cervical ICA arises from the_______
CCA posterolateral to the external carotid artery.
The C1 ICA has two parts, the carotid bulb and the ascending segment.
The _________is the most proximal aspect of the cervical ICA and is seen as a prominent focal dilatation with a cross-sectional area nearly twice as large as that of the distal ICA.
carotid bulb
T or F
The ascending ICA segment courses cephalad in the carotid space, a fascially defined tubular sheath that contains all three layers of the deep cervical fascia. The cervical ICA has no normal branches in the neck.
T
Anastomosis of the Ascending Phar A
Tympanic branch → petrous ICA
Several rami → cavernous ICA
Odontoid arch/musculospinal branches → VA
Maxillar artery anastomoses
Vidian artery → petrous ICA
MMA → inferolateral trunk → cavernous ICA
Artery of foramen rotundum → inferolateral trunk → cavernous ICA
Middle/recurrent meningeal arteries → OA → intracranial ICA
Deep temporal → OA → intracranial ICA
The most common imaging findings in extracranial ASVD are___________
mural calcifications, luminal irregularities, varying degrees of vessel stenosis, occlusion, and thrombosis
CECT and CTA source images display the carotid lumen in cross section. ________________is
the most common finding in ASVD
Nonstenotic smooth luminal narrowing
When ectasia occurs in the posterior circulation,
it is termed_________
“vertebrobasilar dolichoectasia” (
Ectasias can involve any part of the intracranial circulation but are most common in the vertebrobasilar arteries
and________
supraclinoid ICA
_________are focal arterial enlargements that are usually superimposed on an
ectatic artery. ASVD FAs are most common in the vertebrobasilar circulation. When they occur in the anterior
circulation, they can produce a rare but dramatic manifestation called a giant “serpentine” aneurysm
Atherosclerotic fusiform aneurysms (FAs)
While CTA accurately depicts_______ of large intracranial arterial segments (cavernous and supraclinoid ICA, proximal MCA), lesser degrees of stenosis and ASVD in smaller second- or third-order branches are best depicted on DSA.
> 50% stenoses
A _______________—defined as any lesion with an intracranial stenosis > 50% in the same vascular
distribution distal to a primary extracranial stenosis—is present in 20% of patients (10-27). Cumulative stroke
and/or death rate is higher than with either stenosis alone.
“tandem” stenosis
The term __________is sometimes used by neurologists to designate the confluent WM lesions associated with
arteriolosclerosis, i.e., small vessel vascular disease. This is one of the most grossly visible markers that aging and
vascular risk factors inflict on the brain.
leukoariosis
MR. Patchy or confluent periventricular and subcortical white matter hypointensities are seen on T1WI.
The lesions are hyperintense on T2WI and are especially prominent on FLAIR (10-31A). T2* (GRE, SWI) sequences often demonstrate multifocal “blooming” hypointensities, especially in the presence of chronic hypertension.
does not enhance on T1 C+ and does not demonstrate restricted diffusion on DWI.
What are these?
Arteriolosclerosis
Ddx for arteriolosclerosis
is normal agerelated hyperintensities
enlarged perivascular (Virchow-Robin) spaces (PVSs
Demyelinating disease
______________is an uncommon segmental nonatherosclerotic, noninflammatory disease of unknown
etiology that affects medium and large arteries in many areas of the body.
Fibromuscular dysplasia (FMD)
Blood vessels involved in FMD
The cervicocephalic vessels are involved in up to 70% of cases
FMD carries an increased risk of developing _________ It is
present in approximately 7-10% of patients with cervical FMD
IC Aneurysm
The most common type of FMD
By far the most common type (type 1) is
medial fibroplasia, accounting for approximately 85% of all FMD cases. Here the media has alternating thin and
very thick areas formed by concentric rings of fibrous proliferations and smooth muscle hyperplasia
__________can present
with transient ischemia attack, bruit, stroke, or dissection (often with Horner syndrome, i.e., ptosis, pupil
constriction, facial anhidrosis).
Cervical FMD
Meds for FMD
antiplatelet therapy for asymptomatic individuals with cervical FMD.
Percutaneous balloon angioplasty is
recommended for patients with recent-onset or resistant hypertension, TIA, or stroke
In the past, ________was considered the gold standard for the diagnosis of FMD. However, CTA accurately depicts FMD in the cervicocephalic arteries and also allows visualization of the intracranial vessels to detect the presence of associated aneurysms
DSA
What is the problem with TOF MRA in FMD
TOF MRA is problematic because artifacts
caused by patient motion or in-plane flow and susceptibility gradients can mimic the appearance of FMD
Problem with duplex for FMD
Duplex
sonography and color Doppler can depict FMD only when the lesion is located proximally.
What type of FMD?
An irregular “corrugated” or “string of beads” appearance with alternating areas of constriction and dilatation that are wider than the original lumen is the typical appearance
Type 1
FMD
In ____________, a smooth, longsegment tubular narrowing is present.
In__________ FMD, asymmetric diverticulum-like outpouchings from one side of the artery are present
type 2 (intimal fibroplasia)
type 3 (adventitial)
___________is an uncommon but important cause of ischemic stroke in young and
middle-aged adults. Timely therapy can reduce the immediate stroke risk and mitigate long-term sequelae of
craniocervical dissections, so imaging diagnosis is crucial to patient management.
Craniocervical arterial dissection (CAD)
A dissecting aneurysm is a dissection characterized by an outpouching that extends beyond the vessel wall.
Most occur with subadventitial dissections and are more accurately designated as _________(i.e., they lack
all normal vessel wall components).
pseudoaneurysms
Almost _______of extracranial dissections are “spontaneous,” i.e., nontraumatic. The remainder result from blunt or
penetrating injury. Most nontraumatic dissections occur secondary to an underlying vasculopathy such as FMD,
Marfan syndrome, or other connective tissue disorder (e.g., Ehlers-Danlos type 4).
60%
Dissections typically occur in the most mobile segment of a vessel, often starting or ending where the
vessel transitions from a relatively free position to a position fixed by an encasing bony canal.________
is the most common overall site in the head and neck
The extracranial ICA
Sx of AD
Neck pain and headache are the most common symptoms. One or more lower cranial nerve palsies
including postganglionic Horner syndrome may occur. Pulsatile tinnitus is a less frequent presentation
Tx options for AD
Anticoagulation is the recommended treatment for extracranial arterial dissection.
Six months of antiplatelet therapy in asymptomatic patients with stable imaging findings is common
CT findings of AD
NECT may show crescent-shaped thickening caused by the wall hematoma.
Approximately ______of vertebral artery dissections cause posterior fossa subarachnoid hemorrhage
20%
MRI of Arterial dissection
T1WI with fat saturation is the best sequence for demonstrating CAD. A hyperintense crescent of subacute blood adjacent to a narrowed “flow void” in the patent lumen is typical (10-40). T2WI may show
laminated layers of thrombus that __________on T2*
“blooms”
Extracranial ICA dissections typically spare the _________beginning two to three centimeters
distal to the bifurcation and terminating at the exocranial opening of the carotid canal (10-41).
Vertebral dissections are most common around the skull base and upper cervical spine.
carotid bulb,
In arterial dissection, The most common finding on DSA is a smooth or slightly irregular, tapered mid-cervical narrowing. CAD with occlusion shows a flame-shaped______
“rat-tail” termination
Vasospasm with multifocal intracranial foci of arterial constriction and dilation is a common, well-recognized
complication of ______and is the most common cause of severe vasoconstriction
aneurysmal subarachnoid hemorrhage (aSAH)
___________also known as Call-Fleming syndrome) is associated with nonaneurysmal subarachnoid hemorrhage, pregnancy, and exposure to certain drugs.
The diagnosis requires demonstration of multifocal segmental arterial constrictions that resolve, then recur
Reversible cerebral vasoconstriction syndrome,
Involvement of the cortex/subcortical white matter together with the basal ganglia (BG) is strongly suggestive of _______
T1 scans can be normal or show multifocal cortical/subcortical and BG hypointensities.
T2/FLAIR scans demonstrate hyperintensities in the same areas (10-50A). T2* (GRE, SWI) may show parenchymal
microhemorrhages and/or SAH in some cases
vasculitis.
__________is an idiopathic progressive arteriopathy characterized by stenosis of the distal (supraclinoid) ICAs and formation of an abnormal vascular network at the base of the brain
Moyamoya disease (MMD) i
The pathophysiology of MMD has been extensively investigated but remains poorly understood. Genetic,
acquired, and environmental factors have all been implicated. Aberrant expression of _____and ____proteins in
the walls of MMD vessels has been demonstrated, but its significance is uncertain
IgG and S100 A4
Diseases associated with Moya Moya
The disease is also associated with several genetically
transmitted disorders including neurofibromatosis type 1, trisomy 21 (Down syndrome), and a spectrum of
hemoglobinopathies such as sickle cell anemia
The clinical features of MMD in children differ from those in adults. When MMD presents in childhood, the initial
symptoms are usually ______In adults, approximately half of all patients develop______ from
rupture of the fragile moyamoya collateral vessels. The
ischemic.
intracranial hemorrhage
Multiple enhancing punctate______ or _______(MR) in the basal ganglia are the most striking
findings in MMD.
T1 and T2 scans show markedly narrowed ________ with multiple tortuous, serpentine “flow voids”
The appearance of multiple tiny collateral vessels in enlarged CSF spaces has been likened to “______
“dots” (CECT) or “flow voids”
Supraclinoid ICAs
swimming worms in a bare cistern.”
In MOYA MOYA
An ______sign with sulcal hyperintensity from slow flow in leptomeningeal collaterals is sometimes seen on FLAIR
and correlates with decreased vascular reserve in the affected hemisphere.
“ivy”
IN MOYA MOYA
Multiple microbleeds can be detected on T2* GRE scans in 15-40% of patients and are associated with increased risk
of overt cerebral hemorrhage. Susceptibility-weighted imaging (SWI) shows increased conspicuity of deep
medullary veins, an appearance dubbed the _______sign.
“brush”
DSA, CTA, and MRA show predominantly anterior circulation disease with marked narrowing of both supraclinoid ICAs_______
(“bottle neck” sign).
Prominent deep-seated lenticulostriate and
thalamoperforator collaterals are present, forming the________ appearance characteristic of moyamoya.
“puff of smoke”
The differential diagnosis of idiopathic (“true”) moyamoya disease includes other slowly developing occlusive vasculopathies INCLUDING?
Radiation therapy, neurofibromatosis type 1 (NF1), trisomy 21, sickle cell disease, and even atherosclerosis may develop multiple small moyamoya-like collateral vessels.
A unilateral “____ is a rare nonprogressive congenital anomaly that should be differentiated from
MMD
aplastic” or twig-like M1 MCA
CADASIL is caused by highly stereotyped missense point mutations in the______ gene
NOTCH3 gene.
IN CADASIL
Bilateral, multifocal T2 and FLAIR hyperintensities in the periventricular and deep WM begin to appear by age 20.
Although these findings are nonspecific, involvement of the _______ AND ____________has high
sensitivity and specificity in differentiating CADASIL from the much more common sporadic cerebral small vessel
diseas
anterior temporal lobe and external capsule
Uncommon manifestations of CNS amyloid disease include a focal, tumefactive mass-like lesion called an
________
amyloidoma
Rarely, cerebral amyloid disease presents as an _____________with diffuse
inflammatory changes that primarily affect the white matter
amyloid β-related angiitis (ABRA)
Aβ42 is principally found in ______whereas the shorter, relatively more soluble Aβ40 is the major form found in__________
AD-associated neuritic plaques
CAA.
Failure to clear Aβ from the brain has two major consequences:
(1) intracranial hemorrhages associated with rupture of Aβ-laden vessels in CAA and
(2) altered neuronal function caused by pathologic accumulation of Aβ and other soluble metabolites in AD.
Enhancement on CECT is rare in cerebral amyloid disease and occurs only if a focal mass OR _______ is present
(“amyloidoma”) or ABRA is present.
WHAT ARE THE 4 VARIANTS OF THE BRACHIO
CEPHALIC TRUNK
Four arch variants are depicted:
Brachiocephalic trunk (BCT) and R ICA arising from V-shaped common origin ,
L ICA arising from BCT ,
L VA arising directly from arch ,
aberrant R SCA arising from arch as fourth “great vessel
WHAT ANASTOMOSES ARE SHOWN?
Graphic shows numerous anastomoses between the ECA and cavernous ICA, including via the artery of
the foramen rotundum , lateral mainstem artery , and ophthalmic artery
WHAT ARTERY HAS BEEN AFFECTED?
Section through the midbrain in the same case shows an old midline penetrating artery infarction , possibly secondary to an artery of Percheron occlusion. 10-7D. More cephalad section through the inferior third ventricle shows a subacute inferomedial thalamic infarct , consistent with artery of Percheron occlusion
WHAT IS SHOWN IN THIS CEA SPECIMEN?
Carotid endarterectomy specimen shows ulcerated intima , calcification , intraplaque hemorrhage
What is shown in this CTA?
Axial CTA source image shows irregular, ulcerated atherosclerotic plaque along the aortic arch,
proximal descending thoracic aorta.
What is shown in this case of ICA stenosis?
(Left) DSA shows critical ICA stenosis . (Right) MRA in the same case shows a “flow gap”
characteristic of a highgrade flow-limiting lesion.
What sign is shown?
(Left) DSA shows ulcerated plaque causing high-grade, near-total stenosis with a “string”
sign . (Right) Late phase shows the distal cervical ICA . Filling defects are caused by thrombus.
What is shown?
MP-RAGE shows intraplaque hemorrhage with tiny residual lumen in the right ICA,
subintimal hemorrhage in the left ICA
What is your dx?
Longitudinal color Doppler ultrasound shows highgrade ICA stenosis. The arterial lumen is
significantly narrowed with “aliasing” flow artifact due to increased flow velocity.
WHAT VALUES ARE INCREASED IN THIS CASE OF STENOSIS?
Spectral Doppler analysis in the same case shows findings of stenosis. Both PSV and EDV are
markedly increased, consistent with stenosis > 70
WHAT PHENOMENON IS SHOWN?
Longitudinal color Doppler US shows mild subclavian steal with arm resting.
WHAT ARE SHOWN?
Sagittal T1WI in an elderly man without hypertension or dementia
Sagittal T1WI in an elderly man without hypertension or dementia shows an extremely elongated “flow void” of the basilar artery . The dolichoectatic artery indents and elevates the third ventricle , which appears compressed and draped over the basilar bifurcation.
10-24B. Coronal T1 C+ scan in the same case shows slow flow with enhancement in the ectatic basilar artery . Note that the third ventricle is elevated, compressed by the VBD.
WHAT ARE SHOWN?
Autopsy case demonstrates ASVD fusiform ectasias of the ICAs and MCAs . The posterior (vertebrobasilar) circulation is relatively spared .
Autopsy case shows extreme ectasia of the horizontal MCA segment