Transcript ภาพนิ่ง 1 - Walailak University

Imaging of the CNS
Contents
• Diagnostic tools
• Anatomical localization: Brain
• Diseases:
- Infection
- Tumor
- Trauma
- Stroke
- Cord compression
Tools
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Plain film
CT
MR
Angiography
Plain radiography
5 densities
• Air
• Fat
• Soft tissue
(water,muscles,etc)
• Bone, calcification
• Metallic
Advantage & I/C
Adventage
- Convenience
- Safe
- Fast
- Availability
Indication
- Fracture skull
- Increase ICP
- Intrasellar mass
- Osteolytic/
osteoblastic lesion
- Calcifying pathology
View and positioning
PA
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Petrous pyramid อยู่ภายในกระบอกตา
Frontal bone and parietal bone
Frontal sinus
Nasal cavity
Mandible
Roof of orbits
Lateral skull
• Cranial vault
• Suture : coronal and
lambdoid
• Occipital bone
• Sellar turcica
• Floor of cranial fossa
• Clivus
• Nasopharyngeal soft tissue
• Sphenoid air sinus
• lateral of calvarium
• lateral of mandible
• Cervical spine 1st-2nd
Lateral
Suture
Outer table
Diploic space
Sellar turcica
Inner table
External occipital
protuberance
Sphenoid air sinus
Caldwell view
• Orbital wall
• Frontal and ethmoid
sinuses
• Mandible
Maxillary sinus
Caldwell view
Ethmoid sinus
Orbital wall
Towne’s view
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Occipital bone
Lamdoid suture
Foramen magnum
Petrous ridge และ
mastoid sinuses
• Zygomotic arch
• Mandible ส่ วน head, neck
และ rami
Waters’ view
• Facial bone
• Orbital roof
• Maxillary,
frontal and
ethmoid sinus
Waters’ view
Frontal sinus
Orbital wall
Maxillary sinus
Paranasal sinuses
Water’ s view
Caldwell view
Paranasal sinusitis
Air-fluid level at both maxillary and both frontal sinuses
Linear fracture skull right parietal bone
Nasal bone
Fx nasal bone
Outer table destruction : histiocytosis X
Normal sella turcica
Anterior clinoid
Posterior clinoid
Dorsum sellae
Floor of sella
ICP
“loss of dorsum sella sign”
Pituitary tumor
“Double floor sign”
Large intrasella mass
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3
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“ballooning sella”
CT : Pituitary tumour
CECT
CT scan
CT /Spiral CT/ MDCT
CT scan
Advantage
- Axial imaging
- Reconstruction, reformatted to coronal,
sagittal planes
- Providing contrast- noncontrast study
- Differentiation tissues by densities(HU)
- Additional software: CTA, CTV, 3D, CTP
etc.
Indication
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Trauma case
1st line imaging of Stroke
Infection
Tumor
Intracranial calcification
C/I: pregnancy, contrast enhancement
injection: limited in patient with azotemia
Attenuation number of CT (HU)
Hounsfield Units
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CSF = 0-20 HU.
Gray matter = 40 HU.
White matter = 23-46 H
Clot blood & hematoma = 70-100 HU.
Calcification and bone = +100-200 HU.
Fat = -100-200 HU.
Air = >- 600 HU.
Density ของ lesion ใดๆจะดูเทียบกับ gray matter
Normal CT brain
Gray matter
White matter
Basal ganglia
cerebellum
Thalamus
Normal CT brain : Ventricular
system
Temporal horn
Frontal horn
Lateral ventricle
4th ventricle
Occipital horn
Physiologic calcification
• Pineal gland
– Age > 10 year
– Size < 10 mm.
• Basal ganglia
– Middle aged
– Young aged :
hypoxia or
abnormal serum
Calcium
• Choroid plexus
• Dura
– Falx cerebri
– Calcification of
diaphragmatic
sellae
Enhancement by contrast media
• Abnormal blood brain barrier (BBB)
• Identify vascular and dural structures
• Differential pathology by pattern of
enhancement
DSA
ANGIOGRAM – MCA BIFURCATION ANEURYSM
MCA aneurysm
25-YEAR-OLD NORMOTENSIVE MAN WITH
UNEXPLAINED ICH
LT ICA ANGIOGRAM – AVM
Indication
• Gold standard for vascular imaging ( ex.
Aneurysm, AVM)
• Arterial / venous
• Risk=1%
• C/I : azotemia, pregnancy
MRI machine
MRI
• Magnet Field : 0.5-3Tesla
• Pulse sequences : Spin Echo ( SE)
• Parameters
: T1
: T2
: TR
: TE
Advantage MRI
1. Multiplanar imaging
( axial/coronal/sagittal/any planar)
1. No radiation
2. No bony artifact
3. Safer contrast agent (Gadolinium)
4. Best for analysis: posterior fossa and
leptomeningeal lesions
MRI- three planars
Axial
Coronal
Sagittal
Contraindications
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Implantable Cardiac defibrillator
Pace Maker
wt. > 136 Kg
Severe Claustrophobia
Pregnancy (+/- )
Cochlear Implant
Aneurysm Clips
Ferromagnetic eye prosthesis /
F.B.
SIGNAL INTENSITY(SI)
T1W
intermediate
BRAIN
: GM
: WM
high
Muscles
intermediate
Nerve
:dorsal root intermediate
:ventral
intermediate
CSF
low
Fat
high
Pituitary: anterior
Intermediate
posterior
high
Tissue
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T2W
high
low
intermediate
intermediate
high
low
intermediate
high
T1WI
T2WI
MRI of brain tumor
T1W
T2W
T1W-GD