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Title: Neuroradiology%20presents


1
Neuroradiology presents.
2
Neurovascular Anatomy Cases
3
Objectives
  • Neurovascular imaging modalities
  • Review of cerebrovascular anatomy
  • Representative cases

4
Neurovascular imaging
  • Invasive
  • - Digital Subtraction Angiography (DSA)
  • Non-Invasive
  • Ultrasound
  • Carotid ultrasound
  • CTA
  • MRA
  • Time of flight / Phase contrast
  • Contrast-enhanced MRA

5
Egas Moniz - 1934
6
Direct Puncture
Carotid
Vertebral
Lateral
Lateral
AP
AP
7
Sven Seldinger - 1953
8
Digital Subtraction Angiography (DSA)
  • Advantages
  • Gold standard
  • Best detail
  • 3D angiography
  • Arterial/Capillary/Venous phases
  • Planning intervention
  • Disadvantages
  • Time consuming
  • Invasive
  • Low risk of vessel injury, stroke

9
Risks of Angiography
  • Stroke - 11000
  • Contrast reaction - 11,000,000
  • Groin hematoma - 1500
  • Vasovagal reactions, etc.

10
Aortic arch
11
Normal Anatomy -DSA
Lateral Neck
12
Carotid bifurcation
AP
Lateral
13
Normal Anatomy - Carotid
AP
Lateral
14
Phases of angiogramArterial Capillary Venous
15
Middle cerebral artery
Diagnostic Cerebral Angiography, Osborn
16
Lenticulostriates
17
Anterior cerebral artery
Diagnostic Cerebral Angiography, Osborn
18
Vertebral artery
Diagnostic Cerebral Angiography, Osborn
19
Posterior circulation
20
Posterior circulation
AP
Lateral
21
3D-CRA
22
Vascular territories
23
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24
Neurovascular imaging
  • Non-Invasive
  • Ultrasound
  • Carotid ultrasound
  • Transcranial doppler
  • CTA
  • MRA
  • Time of flight / Phase contrast
  • Contrast-enhanced MRA

25
Duplex Carotid Ultrasound (DUS)
26
Carotid ultrasoundBilateral severe ICA stenoses
27
CT angiography
  • Advantages
  • Readily accessible
  • Fast image acquisition
  • Good detail
  • Reconstructions (Ax/Cor/Sag)
  • Disadvantages
  • Radiation
  • Contrast nephropathy
  • Contrast allergy
  • Calcification
  • Metal artifact e.g. clip, coil, stent

28
CT Angiography - CTA
Circle of Willis
Carotid bifurcation
29
MR angiography
  • Advantages
  • No radiation
  • TOF does not require contrast
  • Other sequences DWI, GRE, FLAIR etc.
  • Disadvantages
  • Not as readily accessible
  • Longer image acquisition time
  • Patient motion
  • Slow flow or turbulence
  • Metal artifact
  • Nephrogenic systemic fibrosis (Gadolinium )

30
Aortic arch
31
MR Angiography - MRA
Circle of Willis
32
External carotid artery
Lateral
33
Collateral circulation
  • Primary
  • Circle of Willis
  • Fetal variants
  • Secondary
  • Extra- to intracranial connections
  • e.g. ophthalmic to carotid
  • Leptomeningeal collaterals

John Hunter, 1728-93
34
Thomas Willis 1648
35
Circle of Willis
Ant. communicating artery
A1
Post. communicating artery
P1
36
Cerebral venous system
37
AP
Lateral
38
Stroke
Normal
39
Focal lucency Loss of G/W Mass effect
40
6 hrs
Loss of BG Loss of insular ribbon
24hrs
41
2hrs
Hyperdense Middle Cerebral Artery Sign HMCAS
24 hrs
42
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43
ASPECTS Alberta Stroke Program Early CT Score
44
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45
ASPECTS
  • Normal 10
  • Score lt 7 risk of bleed after TPA is 14x higher
  • Score lt 7 predicts poor functional outcome

46
DWI MRI
Not all acute infarcts are MCA!
47
DWI
48
Acute Infarcts
  • CT - screening, by 3-6 hrs
  • MRI, Diffusion-weighted imaging (DWI) is within
    1hr, confirmatory
  • CT, CTA with CT perfusion
  • MR, MRA with MR perfusion

49
Hemorrhagic transformation
50
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51
Carotid Atherosclerosis
  • Accounts for at least 50 of strokes
  • NASCET - 1991
  • Endarterectomy (CEA) prevents strokes

Severe stenosis
Normal
52
North American Symptomatic Endarterectomy Trial
NASCET
53
KFC
54
Near- occlusion
55
Complete occlusion
Thrombus
56
John Hunter (1728-1793)
Blood goes where it is needed
57
Right ICA occlusion
58
Collateral supply to the brain
Circle of Willis
EC-IC
59
Duplex Ultrasound
Best screening modality
60
DUS and CTA - Good enough for surgery
61
MRA of carotid disease
Good enough for surgery
62
Carotid Angioplasty/Stenting (CAS)
63
Pre-
Post-
64
CAS Techniques
  • Major concern distal emboli

? Value of EPDs
65
Carotid Angioplasty and Stenting (CAS)
  • NASCET
  • Healthy scepticism

The Hype Curve
66
Endarterectomy or stenting?
  • Trials in progress
  • CREST (North America), recruitment of 2500 pts
    completed, results expected in spring 2010
  • ICSS (Europe/Australia)

67
Intracranial Disease
68
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69
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70
Endovascular Therapy for Acute Stroke
71
Left MCA Occlusion
72
Intra-arterial TPA
73
Basilar artery occlusion
Pre-
Post-
74
5K
17 K start-up, 2-3K per case
75
Endovascular Stroke Therapy
  • Time is brain - 2 million neurons/min.
  • Re-perfusion does not always correlate with good
    clinical outcome
  • IV r-TPA within 3 hrs most practical
  • IA - large vessel occlusions (MCA or basilar), up
    to 6 hrs
  • Still no conclusive evidence favouring IA or IV

76
Venous infarcts
77
Dural venous sinus thrombosis
78
Cerebral Aneurysms
79
Common locations of aneurysms
NEJM 2006 355928
80
P.comm
81
A. comm
82
R MCA
83
Aneurysm clipping
84
Endovascular Therapy of Cerebral Aneurysms
85
CT head
86
Right carotid arteriogram
Lateral
AP
87
Oblique projection
88
Post coil embolization20 GDC coils
AP
Lateral
89
Oblique projection
Before
After
90
Clip or coil?
91
Clip or coil? Factors to consider
  • Rupture status
  • Morphology
  • Location
  • Age
  • Comorbidities / Other

92
Clip or coil? Ruptured aneurysms
  • ISAT trial
  • Multi-centre randomized trial of clipping (1070)
    vs. coiling (1073) for patients with ruptured
    intracranial aneurysms
  • Aneurysms were all deemed suitable for either
    coiling or clipping (Only 22 of aneurysms!)
  • Outcome mRS 3-6 at 1 year
  • 6.9 ARR in favor of coiling
  • (NNT 14.5)

Lancet 2002360126774
93
Clip or coil? Unruptured aneurysms
  • What are the indications for treatment?
  • Risk of rupture vs. risk of treatment
  • ISUIA trial

Lancet 200336210310
94
Clip or coil? Unruptured aneurysms
  • Treatment - Clip or coil?
  • No trial comparing clipping/coiling for
    unruptured aneurysms
  • Upcoming RCTs
  • ISUIA IV (Conservative vs. surgery or
    endovascular)
  • TEAM (Conservative vs. endovascular)

95
Clip or coil? Morphology
  • Neck / Base
  • Unfavorable factors for simple coiling
  • Neck gt 4 mm
  • Fundusneck ratio close to 11

Neurosurgery 2000461397-1407
96
Balloon-assisted coiling
Neurosurgery 199741975-978
97
Stent-assisted coiling
NEJM 2006355928-939
98
Stents and Coils
lateral
AP
99
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100
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101
Covered Stent
102
Cerebral Arteriovenous Malformations (AVMs)
103
MRI brain Axial T2
104
MRA Time of flight
105
Right ICA arteriogram
Lateral
AP
106
Left vertebral arteriogram
Lateral
AP
107
Cerebral AVM
  • Abnormal collection of blood vessels where
    arterial blood flows directly into draining veins
    without interposed capillary bed
  • Clinical presentation
  • Asymptomatic
  • Hemorrhage (65)
  • 2-4/yr
  • 10 first year after hemorrhage
  • Seizures (15-35)
  • Headache (15)
  • Progressive neuro deficits
  • Pulsatile bruits

108
Treatment of brain AVMs
  • Observation
  • Surgical resection
  • Stereotactic radiosurgery
  • lt3 cm
  • Takes 1-2 years
  • Endovascular embolization
  • Pre-operative or pre-radiosurgery
  • n-BCA (glue) or Onyx

109
Endovascular Therapy of Brain AVMs
NBCA
crazy glue
110
Onyx embolization x2
111
Post embo
ICA
VA
112
Post surgical resection
ICA
VA
113
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114
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115
What to do?
  • Nothing
  • Radiation
  • Embolization
  • Embo Surgery
  • Surgery
  • ARUBA

116
Treatment of AVMs
  • ? Natural history of unruptured/ruptured AVMs
  • Risk of bleed or disability lt 2/yr?
  • Risks of Embolization - up to 20
  • Risks of Embo Surgery up to 58
  • ARUBA Trial - A Randomized Trial of Unruptured
    Brain AVMs

Hartman et al. Stroke 2005 36 2431-35
117
  • 48 yr. old male
  • MVA 2 months previously
  • Gradual onset L proptosis, chemosis, bruit
  • Sudden onset leg weakness, dysarthria

118
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119
Traumatic (Direct) Carotid Cavernous Fistula
  • MVC
  • Within a few weeks
  • Proptosis, chemosis, bruit, CN palsy
  • transarterial
  • Balloon/coil occlusion
  • transvenous

120
3 months
121
The End
122
External Carotid Artery
123
External Carotid Artery - Lat
124
External Carotid Artery - AP
125
Epistaxis
126
Juvenile Nasal Angiofibroma
127
Tumours
Carotid body tumour
128
Chemodectomas
  • Carotid body tumour
  • Glomus Vagale
  • Glomus jugulare
  • Glomus tympanicum

129
Meningioma
130
Mother - in - Law
131
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