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Dissection of the craniocervical arteries
and dural sinus thrombosis
L. DIVANO, T. STADNIK, C. MABIGLIA
Radiology Department
Brugmann Hospital
Bruxelles – Belgium
XIX SYMPOSIUM NEURORADIOLOGICUM
The World Congress of Diagnostic & Therapeutic Neuroradiology
Bologna 2010
4-9 October
Dissection of the
craniocervical arteries
INTRODUCTION
• 10%–25% of strokes in young patients
• spontaneous or traumatic
• variety of clinical presentations: stroke,
headache, neck pain, tinnitus, Horner syndrome,
and cranial neuropathies
• neurological emergency because of the risk of
cerebral infarct
Arterial dissection: diagnostic considerations
• Before the development of MR
imaging, catheter angiography was
considered the study of choice for
depiction of carotid and vertebral
dissection
(limits: cost and invasiveness).
• MR imaging/MRA and CT/CTA:
alternatives for diagnosis and follow-up
Dissection of craniocervical arteries: MRI
ADVANTAGES
LIMITS
•
DWI  detection of acute
stroke
•
Access to MRI  availability,
patient restrictions
•
Axial T1-weighted fatsuppressed  depiction of
subacute intramural hematoma
(crescent sign)
•
Need for the proper MR
imaging protocol
•
Isointensity of intramural
hematoma in the acute phase
•
Less sensitive for vertebral
artery dissection
•
Confusing high signal intensity
caused by the venous plexus
or fat surrounding the VAs
•
Differentiation between
intramural hematoma and mural
thrombus in an occluded vessel
•
No X-Rays (youngs, pregnancy &
Follow-Up)
•
No iodine contrast
administration
Vertinsky AJNR 29 Oct 2008
Arterial dissection: diagnostic considerations
Diagnostic clue: intramural hematoma
T1
PD
TOF-MRA
Dissection of the craniocervical arteries: CT
ADVANTAGES
LIMITS
•
•
Use of ionizing radiation
(follow-up studies)
•
Need for iodine contrast
injection
Rapid imaging time 
multiplanar and volume
reconstructions
•
More widely available
•
Greater spatial resolution
•
Identification of intimal flaps
and pseudoaneurysms
•
Distinction between a tiny
residual patent vessel lumen
(string sign) and vessel
occlusion
Vertinsky AJNR 29 Oct 2008
Arterial dissection: diagnostic considerations
Findings of arterial dissection on CT angiography
On source images:
• narrowing or occlusion of the
contrast-filled lumen
• the hematoma appears isodense
• the residual lumen is generally
eccentric
Findings of arterial dissection on CT angiography
Always check the source images
PD
FLAIR
T2
DWI
CTA
Both CT and MR angiography
show parietal irregularity
of the left ICA
CE-MRA
Findings of arterial dissection on CT angiography
thrombosis
hematoma is isodense
In case of thrombosis, superiority of MRI
AJNR 25:769-774, May 2004
Dural sinus thrombosis
INTRODUCTION
• relatively uncommon, but serious
neurological complications: venous
infarct
• may be associated with high
morbidity and mortality
• frequently delayed
clinical/radiological diagnosis
• potentially reversible with prompt
diagnosis and appropriate medical care
imaging plays a primary role in the diagnosis
Dural sinus thrombosis: diagnostic considerations
CT
limited value in the diagnosis of dural sinus thrombosis:
Unenhanced CT:
"cord sign" and
"dense triangle sign“
- variability (25%)
Contrast enhanced CT:
"empty delta sign“
- present in only 20 to 30%
of cases
- false positive possible
Giant arachnoid granulations
Dural sinus thrombosis: diagnostic considerations
CT
unenhanced CT can be immediately followed by
venography, thus saving time to diagnosis and
treatment.
CT venography is an effective alternative to MRI
American Journal of Roentgenology 169:1699-1707, 1997
Research Journal of Medicine and Medical Sciences, 4(2):284-289, 2009
Dural sinus thrombosis: diagnostic considerations
CT-venography
ADVANTAGES
LIMITS
• Widely accessible
• Ionizing radiations
• Rapid acquisition no
motion artifacts
• Need for contrast
injection
• Not affected by slow
flow
• Time consuming MIP
reconstructions and
bone subtraction
• No contraindication
(pacemaker,
claustrophobia)
N. Khandelwal
AJR:187, December 2006
CT-venography with Matched Mask Bone Elimination (MMBE)
Dural sinus thrombosis: diagnostic considerations
MRI
high signal intensity of the venous sinuses with all routine
sequences  reliable sign of thrombosis.
RadioGraphics
2007; 27:95–108
Dural sinus thrombosis: diagnostic considerations
MRI
After administration of
contrast material, the central
portion of the sinus typically
fails to enhance
MR venography shows absence of
signal in the affected dural sinus
Dural sinus thrombosis: diagnostic considerations
MRI
ADVANTAGES
LIMITS
• Early detection of
thrombosis
• Long acquisition time
• Associated parenchymal
lesions
• Sensitivity to patient
motion
• No radiations
• Flow-related artifacts
• (No contrast injection)
• Anatomic variability
(asymmetric transverse
sinus)
RadioGraphics 2007; 27:95–108
Sudden onset of altered behaviour and
consciousness
Pseudotumoral appearance
T2
DWI
3D-PC
T2*
T1+C
superior sagittal
sinus thrombosis associated
with
left frontal venous
infarction
T1
There has been recent interest in
evaluating the appearance of
intraluminal venous thrombi on DWI.
Signal hyperintensity in thrombosed
sinuses on DWI has been described.
DWI
T1+GD
RadioGraphics 2006; 26:S19–S43
IN CONCLUSION…
Take home messages:
dissection of the craniocervical arteries
•
Availability, contraindications, and patient tolerance will dictate the
primary technique to be used: MRI or CT
•
MRI better shows intramural hematoma and parenchymal lesions
•
CTA allows better depiction of intimal flaps and pseudoanevrysmal
lesions
•
We must always check the source images
•
MRI: only DWI and axial T1-weighted fat-suppressed images in
patients with a highly suspected dissection on CT/CTA
Take home messages:
dural sinus thrombosis
• Unenhanced CT may show hyperdense
thrombosed dural sinus
• MRI/MRA is the most often used technique
• CT venography (with MMBE) in case of MRI
contraindications or ambiguous MRI
• CT venography is at least equivalent to MRI in
the diagnosis of dural sinus thrombosis
THANK YOU
FOR YOUR KIND ATTENTION