imaging after traumatic brain injury

1. Imaging a(er trauma-c brain
injury
JY Gauvrit, L Riffaud
Radiology & Neurosurgery department, Rennes
Hanoi, Nov 2015

2. Trauma-c Brain Injury (TBI) in France
• 200 000 TBI/year
• 12 000 deaths/year
• 5‰ among 15-25 year-olds
• 50% deaths among <25-year-olds
• Causes as many disabili-es as stroke

3. Objec-ves
• Understanding the indica-ons for cerebral
imaging a(er cranio-encephalic trauma
• Understanding the primary lesions and
secondary complica-ons of cranio-encephalic
trauma
• Understanding post-trauma-c vascular lesions
• Facial fractures and complica-ons

4. Injury mechanisms
Scalp
Bone
Meninges
Brain
Wounds
Fractures,
Depressed skull fractures
Extradural hematomas
Subdural hematomas
Hemorrhages
Contusions
Edema

5. The bump
• Subgaleal Hematoma
Galeal Aponeurosis
Scalp

6. Skull Fracture
• CT
• Tells a story
• Up to skull vertex
• Bones
– Lamina externa (external table)
– Diploë
– Lamina interna (internal table)

7. Skull Fracture

8. Skull Fracture
3D
Volume Rendering
Reconstruc-ons

9. Skull Fracture
open skull fracture = sepsis risk = surgery in emergency
Surgical emergency =
Major displacement-hernia-on -skin opening

10. Skull Fracture

11. Epidural-extradural hematoma
• Between the lamina interna and
dura mater
• Arterial (may involve sinus but not bone suture lines)
• Venous (lacera-on of diploic veins and dural sinus)
Middle cranial fossa
• TBI with loss of consciousness
• Lucid interval
• Secondary clinical signs
• Risk factors: young age, direct impact on fragile areas
(temporal and occipital)
Benign Anterior Temporal Epidural Hematoma: Indolent Lesion with a Characteris<c CT Imaging Appearance a=er Blunt Head Trauma
Alisa D. Gean, MD, , Nancy J. Fischbein, MD, , Derk D. Purcell, MD, , Ashley H. Aiken, MD, Geoffrey T. Manley, MD, PhD, and Shirley I. S<ver, MD, PhD,

12. Epidural-extradural hematoma
CT= Biconvex hyperdense "lens"
monstrous bilateral plane
minimal Infra-tentorial supra-tentorial

13. Epidural-extradural hematoma
Up to skull vertex

14. Subdural hematoma
• Between cerebral convexity and inner surface
of the dura mater
• Vein tear or detachment from the brain
surface (concussion)
Cor-codural veins torn
bridging from their fixed points out into the subdural
space

15. Subdural hematoma
• Involves the bone suture lines but not the
sinuses
• Acute subdural hematoma (SDH) displays
highest mortality rate of all head injuries

16. Subdural hematoma
Acute inter-hemispheric
subdural hematoma
Extremely large acute
subdural hematoma with
significant mass effect

17. EDH SDH
Loca-on Facing the trauma impact Direct impact or decelera-on/
accelera-on
Shape Biconvex hyperdense "lens" Hyperdense crescent blade
Extension Involves the falx cerebri and
tentorium but not the suture
lines
Crosses the suture lines but not
the tentorium or falx
Origin 90% arterial 90% venous
Side Unilateral Unilateral or bilateral
Associated injury 90%: cranial vault fractures 70%: intra-axial injury
(contusions)
Evolu-on in -me Lucid intervals in 50% of cases Immediately present
Other Swirled appearance = ac-ve
bleeding
If presence of air: mastoid or
sinus fracture
In children: suspicion of abuse
Epidural/subdural hematoma

18. Subarachnoid hemorrhage
• O(en "counter-blow" injury a(er direct impact
• Associated with parenchymal contusions

19. Subarachnoid hemorrhage
CT MRI
FLAIR

20. Cerebral contusions
• "Blow"
• "Counter-blow"++
• In typical areas where the brain bounces against
a dural ridge or bony protrusion:
– Temporal lobes
– Inferior surface of frontal lobes
– Lateral sulcus

21. Cerebral contusions
• Edema
• Hemorrhagic
edema
• Hemorrhage
Contusions œdémateuses

22. Cerebral Contusions
CT MRI
FLAIR
MRI
T2*

23. Occipital lobe injury
• O(en severe trauma
• Cranial impact unprotected
by hands or face
• Bifrontal cerebral "counter-
blow" injury (cogni-ve
dysfunc-on+++ anosmia)
• Risk to brain stem due to
shock wave
Cerebral contusions

24. Diffuse axonal injury
• Kine-c
• Decelera-on - accelera-on
– Shearing
• Gray and white maker junc-on
– Cor-cal-subcor-cal
– Basal ganglia
– Mesencephalic
• Severe prognosis
Parizel PM et al Eur Radiol 2005;15:589-81
Nakayama N, et al J neurol neurosurg Psychiatry 2006;77:850-55

25. Diffuse axonal injury
• CT scan underes-mates so….MRI
• Perform MRI each -me the scan results and
neurological workup (GCS) are conflic-ng
• Diffusion: acute
• SWI: subacute, chronic
• Corpus callosum
Parizel PM et al Eur Radiol 2005;15:589-81
Nakayama N, et al J neurol neurosurg Psychiatry 2006;77:850-55

26. CT
MRI
SWI
Diffuse axonal injury
MRI
SWI
MRI
FLAIR

27. Hernia-on
• Supratentorial hernia-ons
1. Cingulate (subfalcial)
2. Central
3. Uncal (inner side temporal lobe)
4. Transcalvarial
• Infratentorial hernia-ons
5. Transtentorial: superior cerebellum
vermis
5. Tonsillar

28. Hernia-on
• Transtentorial hernia-ons
– Subarachnoid perimesencephalic spaces
• Visible: safe
• Effaced: danger

29. Secondary complica-ons
• Vascular injury
• Infec-ons
• Hydrocephalus
Unfavorable outcomes

30. Secondary complica-ons
• Vascular complica-ons
– Dissec-on
– Venous thrombosis
– Caro-d-cavernous fistula

31. Dissec-on
Denver criteria
• Cervical spine
fracture
• Central neurologic
deficit, unexplained
with CT
• CBH syndrome
• Naso-orbito-Ethmoid
fractures
• Skull-base Fracture
• Expanding neck
hematoma

32. Venous thrombosis

33. Caro-d-cavernous fistula

34. Any head trauma represents a
poten-al trauma to the spine

35. What to Remember?
• The bump
• The fracture tells a story
• EDH = mainly arterial, but some-mes venous
• Up to skull vertex
• Chronic SDH = highest mortality rate of all encephalic
injuries
• "Blow" and "counter-blow" injuries
• MRI when clinical (GCS) and CT disagree
• Subarachnoid perimesencephalic spaces
• Secondary complica-ons = unfavorable prognosis
• Any head trauma represents poten-al trauma to the
spine

36. European project TBI