2. Cranial trauma is a major problem in accident and
emergency departments and in one series
provided 10% of the patients seen.
It is also responsible for 150 000 hospital
admissions per year in the UK
3.
It is not necessary for every patient who suffers a
head injury to undergo a CT scan. In the acute
phase, the indications are deterioration of the
patient's conscious level, with or without focal
neurological signs..
4.
Sedation and/or general anesthesia should be
employed without hesitation when indicated, since
the recently traumatized patient may be very
restless
5.
6. Accumulation of blood in the potential space
between dura mater and bone
EDH is considered to be the most serious
complication of head injury, requiring immediate
diagnosis and surgical intervention (mortality rate
associated with epidural hematoma has been
estimated to be 5-50%)
7. Usually results from a brief linear contact force
to the calvaria that causes separation of the
periosteal dura from bone and disruption of
interposed vessels due to shearing stress
Skull fractures occur in 85-95% of adult cases
Extension of the hematoma usually is limited by
suture lines owing to the tight attachment of the
dura at these locations.
The temporoparietal region and the middle
meningeal artery are involved most commonly
(66%)
8.
Epidural hematoma complicates 2% of cases of head
trauma (approximately 40,000 cases per year)
Alcohol and other forms of intoxication have been
associated with a higher incidence of epidural hematoma
Sex
◦ more frequent in men, with a male-to-female ratio of 4:1
Age
◦ rare in individuals younger than 2 years
◦ rare in individuals older than 60 years because the dura is tightly
adherent to the calvaria
9.
10. Head trauma
Lucid interval between the initial loss of
consciousness at the time of impact and a
delayed decline in mental status (10-33% of
cases)
Headache
Nausea/vomiting
Seizures
Focal neurological deficits (eg, visual field cuts,
aphasia, weakness, numbness)
11.
Noncontrast CT scanning of the head (imaging study of
choice for intracranial EDH) not only visualizes skull
fractures, but also directly images an epidural hematoma
It appears as a hyperdense biconvex or lenticular-shaped
mass situated between the brain and the skull, though
regions of hypodensity may be seen with serum or fresh
blood
MRI also demonstrates the evolution of an epidural
hematoma, though this imaging modality may not be
appropriate for patients in unstable condition
12.
13.
14.
15.
Rapidly clotting blood collection below the inner layer of
the dura but external to the brain and arachnoid
membrane
Typically, low-pressure venous bleeding of bridging
veins (between the cortex and venous sinuses) dissects
the arachnoid away from the dura and layers out along
the cerebral convexity
It conforms to the shape of the brain and the cranial
vault, exhibiting concave inner margins and convex outer
margins (crescent shape)
Frequency is related directly to the incidence of blunt
head trauma
It’s the most common type of intracranial mass lesion,
occurring in about a third of those with severe head
injuries
16.
Mortality
◦ Simple SDH (no parenchymal injury) is associated with a
mortality rate of about 20%
◦ Complicated SDH (parenchymal injury) is associated with a
mortality rate of about 50%
Age
◦ It’s associated with age factors related to the risk of blunt head
trauma
◦ More common in people older than 60 years (bridging veins are
more easily damaged/falls are more common)
◦ Bilateral SDHs are more common in infants since adhesions
existing in the subdural space are absent at birth
◦ Interhemispheric SDHs are often associate with child abuse
17.
18.
Usually involves moderately severe to severe blunt head
trauma
Acute deceleration injury from a fall or motor vehicle
accident, but rarely associated with skull fracture
Generally loss of consciousness
Any degree or type of coagulopathy should heighten
suspicion of SDH
Commonly seen in alcoholics because they’re prone to
thrombocytopenia, prolonged bleeding times, and blunt
head trauma
Patients on anticoagulants can develop SDH with
minimal trauma and warrant a lowered threshold for
obtaining a head CT scan
19.
MRI is superior for demonstrating the size of an acute SDH
and its effect on the brain, however noncontrast head CT is
the primary means of making a diagnosis and suffice for
immediate management purposes
Noncontrast head CT scan (imaging study of choice for acute
SDH)
◦ The SDH appears as a hyperdense (white) crescentic mass along the
inner table of the skull, most commonly over the cerebral convexity in
the parietal region. The second most common area is above the
tentorium cerebelli
Contrast-enhanced CT or MRI is widely recommended for
imaging 48-72 hours after head injury because the lesion
becomes isodense in the subacute phase
In the chronic phase, the lesion becomes hypodense and is
easy to appreciate on a noncontrast head CT scan
20.
21.
22. Subdural hematoma - Axial CT scan though the level of the lateral
ventricles shows right-sided subdural hematoma along the convexity (red
arrow) and falx (green arrow), with severe midline shift from right to left
23. Isodense subdural. Note mass effect and
effacement of sulci which suggest
diagnosis prior to contrast medium.
24. Post-enhancement scan of another
isodense subdural. The lesion stands out
against the enhanced surface of the brain
25. Epidural
Hematoma
◦ Potential space between the
dura and the inner table of
the skull
◦ Can’t cross sutures
◦ Skull fractures in
temporoparietal region
◦ Middle meningeal artery
◦ Lenticular or biconvex
shape
◦ Lucid interval
◦ Common in alcoholics
◦ Medical emergency
◦ CT without contrast
◦ Evacuate via burr holes
Subdural
Hematoma
◦ Between the dura mater and
the arachnoid mater
◦ Can cross sutures
◦ Cortical bridging veins
◦ Crescent shape
◦ Loss of consciousness
◦ Common in elderly
◦ Common in alcoholics
◦ Medical emergency
◦ CT without contrast
◦ Evacuate via burr holes
26.
27. Traumatic intracerebral haematomas
It may be impossible to distinguish these from
spontaneous intracerebral haemorrhage.
The frontal and temporal lobes are classic sites,
which are less commonly affected by spontaneous
episodes.
28. Both types are of high density, but traumatic
bleeding is more frequently multifocal and in
cases with a poor prognosis may be seen to
involve the brainstem.
It is also more commonly associated with lowdensity areas and brain swelling, even in the
acute stages.
29. The blood may extend to the ventricles or the
subarachnoid space.
Retrobulbar or subperiosteal orbital haematomas
are readily diagnosed in the context of head
trauma as high-density lesions within the orbits or
applied to the bone
31. NECT Brain showing right temporoparietal
intracerebral hematoma with mass effect .
32. Cerebral contusion and edema
Two types of cerebral contusion may be detected
by CT scanning:
hemorrhagic and non-hemorrhagic.
33. Hemorrhagic contusion
commonly seen in the frontal and temporal lobes,
although any part of the cerebrum, cerebellum or
brainstem may be affected.
34. It appears as a mass lesion of mixed high and low
density not dissimilar to multifocal traumatic
hemorrhage, but generally more diffuse-the area
of swelling may be very extensive.
The hemorrhagic areas may not be evident in the
very acute stage, occurring only 24 hours or more
later.
35. Non-haemorrhagic contusion
cannot reliably be distinguished from cerebral
oedema, but tends to be more focal and spaceoccupying. Considerable enhancement may be
seen with intravenous contrast medium; this does
not occur with oedema.
38. Diffuse brain damage
About 50% of patients who suffer immediate
prolonged unconsciousness following a head
injury have no obvious mass or focal lesions.
this is true of about one-third of fatal cases.
39. In these patients the lesions present have been
classified into four types:
1. Multiple petechial haemorrhages
2. Diffuse axonal injury
3. Brain swelling
4. Hypoxic brain damage.
40. Multiple petechial haemorrhages
This type of injury is seen throughout the white
matter and brainstem and is rapidly fatal. It is
therefore more likely to be seen at postmortem
than in an imaging department.
41. Diffuse axonal injury (white matter
shearing)
This severe injury may show virtually no
macroscopic change in the affected brain.
There is disruption of axons in the subcortical
parasagittal white matter and in various other
sites, including the internal and external capsules,
fornix and cerebellum
42.
It is claimed to result from acute lateral
acceleration or deceleration of the brain within the
rigid cranium and can occur without anything
actually striking the head. It occurs most
commonly in automobile accidents.
43. The patient is unconscious from the moment of
impact and remains unconscious, vegetative or
severely disabled until death.
Despite the severe brain damage and the very
grave state of the patient there may be little or
nothing shown at imaging
44.
Small focal haemorrhages have been described in
the corpus callosum and in the posterolateral
quadrant of the rostral brainstem and such lesions
could theoretically be demonstrated, as can small
subcortical haemorrhages.
45. Brain swelling
Diffuse swelling of the entire brain occurs mainly
in children and adolescents. The pathogenesis is
debated and it is thought to be due to
vasodilatation and increased cerebral blood
volume in the first place.
46.
Diffuse swelling of the ipsilateral hemisphere can
also occur with local and mass lesions , including
acute subdural haematoma and extensive
unilateral contusions. Focal oedema may also
occur with haemorrhages and contusions.
47.
With diffuse bilateral swelling the ventricles are
compressed and appear small, like slits, at
imaging; the basal cisterns may be occluded and
the sulci effaced. The white matter shows no
reduction in density and appears normal at CT,
although evidence of oedema may be seen in
cases with prolonged coma
48. 1)Subcortical small haemorrhages associated with
shearing injury, and a few large haemorrhages.
(2) Head injury in a child. There is cerebral
oedema mainly on the left, associated with
compression of the ventricles and some shift to the
right.
49. Hypoxic damage
This is due either to a prolonged drop in systolic
blood pressure, or to arterial spasm, or to both.
Evidence of hypoxic damage is seen in the first
place at major arterial boundary zones, and frank
infarction may later ensue.
50.
Hypoxia and subsequent infarction may also result
from brain swelling and tentorial herniation
compromising the posterior cerebral circulation, or
from trauma to major vessels. Imaging may show
little in the early stages but later will demonstrate
evidence of infarction.
51. Skull fractures
Fractures are, in most instances, best diagnosed
by a combination of clinical features and plain
radiography.
However, basal fractures, which are often difficult
to demonstrate or to assess fully by these means,
may be shown very clearly by CT scanning.
52. Depressed fractures can be clearly demonstrated
and their relationship to the underlying brain better
shown than by plain X-ray films.
However, the chief value of the CT scan is in the
assessment of underlying brain damage and
haematoma formation.
53. (A) Depressed fracture in the left temporal region
with underlying
Haemorrhagic contusions.
(B) Same case at higher level to show bone detail
54. Intracranial air
Whether subdural or subarachnoid, air is well
shown by CT and implies a dural tear
communicating with a sinus or other air-containing
cavity. Intracerebral air (aerocele) is also well
shown and its site of origin can be identified prior
to surgery.
55. (C) Frontal aerocele.
(D) Bone window film
showing frontal fracture and
connection with top of frontal sinus.
56. Foreign bodies
Intracranial foreign bodies may be accurately
localized by CT scanning. The value of the
technique is in the demonstration of the position of
the foreign body relative to, and its effects on, the
intracranial structures, features which cannot be
seen on plain radiographs.
57.
Good demonstration of the relationships of
metallic objects may, however, be prevented by
the resulting artifacts. Wooden fragments may
appear less dense than brain.
58. CT scan showing the wooden foreign body (13 x 2.7 x 2.5 cm)
entering the right temporal bone and reaching the left parietal bone with blood
along its path
Slide #8 Epidural Hematoma Case
A 32 y/o man presented to the ER after slipping on ice in his driveway. The patient fell backwards and hit his head on the ground. The patient got up and returned to his house and told his wife what had happened. After about 20 minutes of sitting the patient began complaining of a headache. Approximately one hour after the fall the patient became disoriented and obtunded. The patient's wife immediately called an ambulance, which brought him in to the ER. On arrival the patient was obtunded to the point that he could not answer or respond to questions. The CT on the left was taken shortly after arrival.
Diagnosis: Epidural Hematoma
On CT, epidural hematomas appear as well-defined, high attenuation lenticular or biconvex extra-axial collections. Associated mass effect with sulcal effacement and midline shift is frequently present. Overlying linear skull fractures can often be visualized on bone windows. If an epidural hematoma appears heterogeneous, containing irregular areas of lower attenuation, this can indicate active extravasation of fresh unclotted blood, requiring immediate surgical attention. Alternatively, areas of low attenuation can represent serum extruded from the clot.
Slide #9
CT of the head obtained without intravenous contrast enhancement shows a biconvex high-attenuation epidural hematoma adjacent to the right frontal lobe (arrows). The lesion extends superiorly to the level of the body of the lateral ventricle (arrow)
Slide #10
and inferiorly to the roof of the right orbit (arrow). Mild mass effect is exerted on the subjacent brain parenchyma. A fracture is visible extending through the right side of frontal bone (arrow)
Slide #16 Subdural Hematoma Case:
A 26 yo female presents to her family practice physician complaining of a headache that has persisted for over one month and sporadic blurry vision that has worsened over the last week. The headache is only slightly relieved with Ibuprofen and is worse when doing strenuous activity. The blurry vision comes and goes and can last minutes to hours when it is present. The neurologic and physical exams are normal except for some slight papilledema. The patient was then sent for a CT exam, the results of which are shown here.
Diagnosis: Subdural Hematoma
