CT BRAIN Anatomy

8/2/2019 CT BRAIN Anatomy

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Division of diencephalon

Pars dorsalis

1)Thalamus 2)Metathalamus- medial and lateral geniculate

bodies

3)Epithalamus - Pineal gland ,habenular nucleiand commissure and post commisure

Pars ventralis 1)subthalamus

2)hypothalamus


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PINEAL GLAND- HAS TWO LAMINAE

VENTRAL LAMINAE IS CONTNIOUS WITHPOST COMMISSURE

DORSAL LAMINAEIS CONTINIOUS WITH

HABENULAR COMMISSURE


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CAUDATE NUCLEUS

LENTIFORM NUCLEI-MEDIAL GLOBUSPALLIDUS AND LATERAL PUTAMEN

AMYLOID NUCLEAR COMPLEX

CLAUSTRUM

SUBTHALAMIC NUCLEUS

SUBSTANTIA NIGRA


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Three membranes (the meninges) envelop the brainand spinal cord: pia, arachnoid, and dura


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Questionaire

#8.6

Common cause of intracranial hemorrhage in a county hospital

emergency room.a) Rupture of arterio-venous malformation

b) Rupture of cerebral aneurysm

c) Trauma

d) Hypertension

e) Stroke


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Questionaire

#8.7

Likely cause of nontraumatic intracranial hemorrhage in an 8 year-old girl.

a) Rupture of arterio-venous malformationb) Rupture of cerebral aneurysmc) Hypertensiond) Stroke


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Hyperacute

Swirl Sign


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Hyperacute

Swirl Sign


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SubacuteIso-dense

C+


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8.1 Non-contrast CT Brain

CT Density 68.6 HU(Hounsfield Units)

Acute Intracerebral hematoma:

Acute hematoma is seen by non-contrast imaging as an area of high densitywith density numbers ranging from 40 to 90HU.

CT can detect acute intracerebral blood as small as 2mm, due to contrastbetween high-density of blood and low-density of surrounding brain

(arrows).

Figure 1: Acute intracerebral hematoma withinthe right temporal lobe (arrow) withsurrounding edema (E).

60 year-old patient with melanoma.Hemorrhage is from metastatic tumor bleed.

E


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Acute subdural hematoma covering theright cerebral hemisphere (arrows), moreprominent posteriorly.

CT density of blood is 74HU consistentwith acute blood. Patient with history ofrecent fall.


Acute Subdural Hematoma:

Subdural hematoma is located between thelayers of dura and arachnoid mater, coveringthe cerebral hemispheres whereasintracerebral hematoma is localized within

the brain substance.

Acute subdural hematoma is recognized byCT as an area of peripheral zone of crescenticshaped increased density, outside the surfaceof the brain (arrows).

Most subdural hematoma is caused by tear ofbridging cortical veins.

Acute subdural hematoma can evolve over aperiod of time and thus classified as acute,subacute and chronic hematoma.

Acute Subdural Hematoma : Up to 7 day old

High CT density (40-90HU)

Subacute Subdural Hematoma (7 to 21 days old)

The CT density of acute blood graduallydecreases and becomes isodense with

adjacent brain, thus less readily visible andcan be easily overlooked.


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8.3a. Non-contrast CT Brain 8.3b&c. Non-contrast CT Brain

Chronic Subdural Hematoma:Over 21 days old: Acute blood as it evolves, it undergoes liquefaction, and also mixes withcerebrospinal fluid from adjacent subarachnoid space, thus converting into a serosanguineousfluid. This fluid has low CT density reaching close or similar to cerebrospinal fluid. Slowmovement of subarachnoid fluid into the subdural hematoma can give rise to gradualexpansion of subdural hematoma that can exert mass effect upon the adjacent brain with orwithout brain edema. This can produce herniation of the brain resulting in suddendecompensation of the patient leading to coma.

Thus even a chronic subdural hematoma mi ht need an emer ent neurosur ical intervention.

09/02/2003

09/21/2003

CT Density 25.0 HU(Hounsfield Units)

A: Left frontal chronic subdural hematoma (arrowheads) seen as an area of low-density withcrescentic inter margin, compressing the adjacent brain.B: Left frontal subdural hematoma was completely evaluated using burr holes in the skull, but theright chronic subdural hematoma has increased in size in the follow-up CT done 19 days later(arrows) which was also subsequently evaluated. 55 year-old patient with chronic myelogenousleukemia with low platelet count.


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Intraventricular Hemorrhage:

Intraventricular blood is easilyrecognized by high-density bloodoutlining the lateral ventricles, III

ventricle and IV ventricle.

Shunt-induced (arrow), intraventricular

blood (v). Intraventricular blood isrecognized by replacement of normalCSF density by high-density of blood.

v


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8.2. Non-contrast CT Brain 8.2 Non-contrast CT Brain

CT Density 72.9 HU

Q8.2. Diagnosis Please


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8.3a. Non-contrast CT Brain 8.3b&c. Non-contrast CT Brain

Q8.3. Diagnosis Please

09/02/2003

09/21/2003

CT Density 25.0 HU


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thank

you

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CT BRAIN Anatomy