CT scan in head and
spine injuries
BY : DR AHMED MOHAMMED DEBES
‫سایت جامع رادیولوژی‬
WWW.RADIOLOGYHA.COM
Brief history
Hounsfield Units
tissue’s attenuation coefficient the ability
to “block” X-rays. relatively constant
mapped onto Hounsfield scale
from –1000 (black) to + 1000 (white).
the brain tissue is the point of
reference.
Any tissue “whiter” than brain tissue is
hyper dense
while any tissue “blacker” than brain
tissue is hypo dense
Basic physics
Image acquisition
I - Skull
Fracture
VHerniation
II –
Pneumocephalus
What to look for in CT LOOK
scan brain of a head trauma
for
patient ?
IV Cerebral
Edema
III Hematoma
Look in head CT bone window
I - Linear, non-depressed
fracture
I - Skull Fracture
II - Depressed fracture
Consider open when
- Skin laceration over the fracture
- Through par nasal sinuses, middle
ear structures
Surgical elevation in
- Depressed > 5 mm and overlies
motor or speech areas
- Depressed > skull thickness
Causes laceration of Dura, arachnoid
and possible brain parenchyma
III - Diastatic fracture
Spreading of suture, 1-2 mm more
than normal contralateral side
May tear Dural venous sinus
IV - Basilar fracture
Presentations
- CSF otorrhea, bruising over
mastoid (Battle sign)
- CSF rhinorrhea, bruising around
the eyes (raccoon eyes)
Presence of air in the cranial cavity
Indicates communication between
intracranial and extra cranial spaces
complications:
meningitis, CSF otorrhea or rhinorrhea
II - Pneumocephalus
I - Epidural Hematoma
Source of bleeding
most commonly middle meningeal
artery
Don't cross sutures
Hyper dense biconvex extra-axial
mass
III - Hematoma
II - Subdural Hematoma
Source of bleeding
torn cortical bridging veins
Can cross suture
Can extend into interhemispheric
fissure
Hyper dense crescent blood
collection
III - Traumatic Subarachnoid
Hemorrhage
Source of bleeding
Tear of veins in subarachnoid space
High density blood in sulci/cisterns
IV - Cerebral Contusion
due to cerebral gyri impact inner
table of the skull
Evolve from petechial hemorrhage ->
small hemorrhage ->large hematoma
Multiple, bilateral
MRI is better for detection
Generally resolves within 2 weeks
- loss of grey/white matter interface
- compressed ventricles
- effacement of the sulci
III - Cerebral Edema
I - Midline Shift & Subfalcine
Herniation
Subfalcine herniation is herniation of
Cingular gyrus underneath the falx
cerebri.
Presence of midline shift usually
signify Subfalcine herniation, and vice
versa.
IV - Herniation
II - Transtentorial herniation
Central herniation is defined as both
temporal lobes descend through the
tentorial incisura
Effacement of the cistern
around the midbrain
III - Tonsillar Herniation
- obliteration of CSF space
- displaced portions of cervicomedullary junction
I - Compression fracture
CT scan in spine trauma
II – Burst fracture
III – Flexion fracture
III – fracture dislocation