Intracranial tumour&tumour like cystic lesion Dr Ahmed Esawy CT MRI 6
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Transcript of Intracranial tumour&tumour like cystic lesion Dr Ahmed Esawy CT MRI 6
Tumors and tumors like
cysts intracranial
Dr Ahmed Esawy
ARACHNIOD VERSUS EPIDERMIOD
epidermiod Lower density than CSF
May show calcifications
invade structures
CT
LOWER THAN CSF MRI T1
HIGHER THAN CSF MRI T2
HIGH SIGNAL FLAIR
BRIGHT typical hyperintensity
T2 shine (restricted diffusion)
DIFFUSION
DARK lower than that of CSF and equal
to or higher than
that of brain parenchyma
ADC
Away from midlline CPA
, supra and parasellar region
middle cranial fossa and
cisterna magna
LOCATION
Dr Ahmed Esawy
T2
CT+no C CT+C
EPIDERMIOD AT CPA
Dr Ahmed Esawy
T2
T1+C
DIFFUSION
Epidermoid tumour
Dr Ahmed Esawy
Epidermoid, brain. CT+no C
, located in the middle cranial fossa with extension into the suprasellar cistern..
Dr Ahmed Esawy
Epidermoid, brain.
T2 T1+no C DIFFUSION
FLAIR
Dr Ahmed Esawy
epidermoid cysts
Dr Ahmed Esawy
EPIDERMOID
CYST
diffusion-shows markedly restricted diffusion (arrows .)
Dr Ahmed Esawy
T2WI T1WI
DWI ADC
End of images
EPIDERMOID
CYST
B 1000 ADC
Dr Ahmed Esawy
ARACHNIOD VERSUS EPIDERMIOD
epidermiod arachniod Lower density than CSF
May show calcifications
invade structures
CSF density
No calcification,no enhancment
displace structures
CT
LOWER THAN CSF Low signal like CSF MRI T1
HIGHER THAN CSF high signal like CSF
MRI T2
HIGH SIGNAL Low signal like CSF
FLAIR
BRIGHT typical hyperintensity
T2 shine (restricted diffusion)
DARK hypointensity
(free diffusion)
DIFFUSION
DARK lower than that of CSF and equal
to or higher than
that of brain parenchyma
BRIGHT marked
hyperintensity
like CSF
ADC
Away from midlline CPA
Retrocerebellar,CPA
Dr Ahmed Esawy
Differential Diagnosis
• arachnoid cyst. Arachnoid cysts are isointense to CSF at all
sequences, including FLAIR. They displace rather than invade structures such as the epidermoid. Finally, arachnoid cysts do not restrict on diffusion-weighted image .
• Dermoid cysts are typically located along the midline and resemble fat, not CSF .
• Cystic neoplasms often enhance and do not resemble CSF .
• Neurocysticercosis cysts often enhance and demonstrate surrounding edema or gliosis .
Dr Ahmed Esawy
Dermoid cyst
location Midline plane, posterior fossa, suprasellar area and Intraventricular
MRI: high signal in T1 [ fat ]
Dr Ahmed Esawy
CT: fat density ± calcification, no
enhancement
Dermoid cyst
Dr Ahmed Esawy
Dermoid tumor 26-Y M
cystic lesion is present in the right temporal lobe+
peripheral marginal calcification in the lesion
partial marginal
enhancement
T1+C
multiple small foci of hyperintense signal are present along the sulci of the right temporal lobe. These represent fat droplets in the subarachnoid space from the focal rupture of the dermoid tumor.
T1+C
T1+NO C
Dr Ahmed Esawy
Rupture intraventricular or subarachnoid → fat /fluid level
Dr Ahmed Esawy
Dermoid tumor. The high signal intensity areas in the
subarachnoid space of the Sylvian fissures and ambient cisterns
represent lipid material from the tumor that has contaminated the CSF
Dr Ahmed Esawy
Suprasellar rupture dermoid tumours
T1W
Fat globules, which have spilled into the
subarachnoid space, are seen as high
signal foci in the left Sylvian fissure Dr Ahmed Esawy
posterior fossa lesion with posterior mural nodule
Unusual Imaging Appearance of an Intracranial Dermoid Cyst
Dr Ahmed Esawy
Ruptured dermoid cyst
• mixed-signal-intensity lesion in the pineal region (straight arrow) with multiple hyperintense droplets scattered through the subarachnoid space (curved arrows). Moderate hydrocephalus is present ..
T1+no C
Dr Ahmed Esawy
Differential Diagnosis
• Epidermoid (typically resemble CSF (not fat), lack dermal
appendages, and are usually located off midline)
• Craniopharyngioma (suprasellar, with a midline location, and demonstrate nodular calcification. craniopharyngiomas are strikingly hyperintense on T2 enhance strongly.
• teratoma
• lipoma .
Dr Ahmed Esawy
CT +no C
epidermiod tumour (inclusion cyst) of Quadrigeminal cistern
Quadrigeminal cistern cyst
Dr Ahmed Esawy
CT +C
epidermiod tumour (inclusion cyst) of Quadrigeminal cistern
displacment of choriod plexus and the body of lateral ventricle
Dr Ahmed Esawy
MRI T1+C
epidermiod tumour (inclusion cyst) of Quadrigeminal cistern
Compression of quadrigeminal plate and cereberal aqueduct
Dr Ahmed Esawy
MRI T2 Quadrigeminal cistern
Dr Ahmed Esawy
Differential Diagnosis
of Quadrigeminal cistern cyst
• Arachniod
• Teratoma
• Cystic pineal tumour
Dr Ahmed Esawy
craniopharyngioma
Dr Ahmed Esawy
CT+C large suprasellar cyst with several nodular calcifications of varying size (arrow) in the wall of the cyst
T1+C cystic intra-/suprasellar mass with strong contrast enhancement of the cyst wall (arrow). The cyst contents are isointense with gray matter, reflecting their high protein content.
T2-strongly hyperintense homogeneous cyst contents. The well circumscribed cyst (arrow) displaces the anterior cerebral arteries anteriorly and the middle cerebral arteries bilaterally
Craniopharyngioma in a child
Dr Ahmed Esawy
Craniopharyngioma in an adult T2
T1+C
Dr Ahmed Esawy
cystic astrocytoma
Dr Ahmed Esawy
hemangioblastoma
Dr Ahmed Esawy
postcontrast T1
facial schwannoma associated with large
arachnoid cyst )(open arrow .)
postcontrast T1
large pituitary macroadenoma with multiple
cysts (arrows) surrounding the suprasellar
component trapped PVSs
NEOPLASM-ASSOCIATED BENIGN
CYSTS
Dr Ahmed Esawy
cystic metastasis
NEOPLASM-ASSOCIATED BENIGN
CYSTS
Dr Ahmed Esawy
T1W post-contrast i dark DW bright on the ADC map
Cystic metastasis from CA breast
unrestricted diffusion in the center of the mass
Dr Ahmed Esawy
large right cerebellopontine angle tumour with a medial cystic component.
Cystic vestibular schawannoma T2W
Dr Ahmed Esawy
Cystic astrocytoma
Dr Ahmed Esawy
II- Magnetic resonance imaging:
• MRI emerged as the imaging
modality of choice for most
intracranial abnormalities. This is
especially true for lesions located in
the posterior fossa, where the
sensitivity of CT is limited by beam-
hardening artifacts from the petrous
bone.
Dr Ahmed Esawy
• If metastases are to be excluded,
heavily T1-weighted pre- and
post-contrast images can be
obtained. Intravenous contrast is
a routine for tumor and infection
investigation.
Dr Ahmed Esawy
• A potential drawback of SE images
is that they may not reliably show
the internal architecture or
morphology of cystic masses. If
the solid portion does not
enhances with contrast material, it
difficult to determine whether the
mass is simple cyst or a cyst with
solid component.
Dr Ahmed Esawy
• Fluid-attenuation inversion-recovery
(FLAIR) MRI belongs to a family of
inversion-recovery sequences, that
generates heavily T2-weighted
images with nulling/subtraction of
the CSF sign and enable improved
characterization of complex cystic
masses.
Dr Ahmed Esawy
Functional studies of cystic brain lesion
Dr Ahmed Esawy
N-acetylaspartate (NAA)
creatine-phosphocreatine(Cr)
choline (Cho).
amino acid, lactate, alanine, acetate,
pyruvate, and succinate
MR spectroscopy
Dr Ahmed Esawy
primary cystic neoplasm versus metastases
primary cystic neoplasm choline
Cystic metastases where no choline resonance
is seen
Dr Ahmed Esawy
necrotic or cystic neoplasms Pyogenic brain abscesses
Elevated choline , decrease
NAA
elevated peaks of amino acid,
lactate, alanine, acetate,
pyruvate, and succinate
absent signals of NAA,
creatine, and choline
MRS
facilitate diffusion
dark
restricted diffusion
bright
DW
Bright on ADC map
The walls of necrotic or cystic
tumors have a lower ADC
value than of an abscess
markedly reduced ADC maps. ADC
wall of necrotic or cystic
neoplasms tends to have higher
rTBV
capsule of an abscess tends to
have lower rTBV
MR PERFUSION
Dr Ahmed Esawy
CT and MR stereotactic biopsy:
Solid contrast enhancing areas are preferred for biopsy rather than cystic, necrotic, or hemorrhagic tumor regions.
Cystic brain lesion biopsy and treatment
Dr Ahmed Esawy
Image guided therapy:
CT and MRI have revolutionized the diagnosis and management of brain abscesses. If excisional neurosurgery is not immediately or otherwise indicated an attempt at abscess aspiration should be made usually guided by CT when the lesion is accessible. Also intraoperative imaging using MR allows for precise localization of the lesion and its relationship. Dr Ahmed Esawy
THANK YOU
Dr Ahmed Esawy
THANK YOU
Dr Ahmed Esawy