NEURORADIOLOGY NEURORADIOLOGY Part I Part I Vörös Erika Vörös Erika University of Szeged University of Szeged Department of Radiology Department of Radiology SZEGED SZEGED
NEURORADIOLOGYNEURORADIOLOGY
Part IPart I
Vörös ErikaVörös ErikaUniversity of SzegedUniversity of Szeged
Department of RadiologyDepartment of RadiologySZEGEDSZEGED
BRAIN
• Developmental anomalies
• Cerebrovascular disorders
• Tumours
• Inflammatory diseases
• Trauma
DISEASES OF CNS
BRAIN IMAGING METHODS
• Plain film radiography
• Ultrasonography (US)
• Computer tomography (CT)Computer tomography (CT)
• Magnetic resonance imaging (MRI)Magnetic resonance imaging (MRI)• Digital subtraction angiography (DSA)• (Cisternography, ventriculography)
DISEASES OF CNS
DEVELOPMENTAL ANOMALIES
DISEASES OF CNS
CNS9.3%
DEVELOPMENTAL ANOMALIES:(due to some NOXA in the fetal life)
Stage 1: Weeks 3 - 4 Dorsal Induction: Formation and Closure of the Neural TubeThree phases: Neurulation, canalization, retrogressive differentiation Failure: Anencephaly, Cephalocele, Chiari, Spinal dysraphism
Stage 2: Weeks 5-10 Ventral Induction: Formation of the Brain Segments and FaceThree vesicles (prosencephalon, mesencephalon, and rhombencephalon) form the cerebrum, mid-brain, cerebellum, and lower brain stem. Division into two hemispheres. Failure: Holoprosencephalies, Corpus callosum agenesis, Dandy Walker,Facial anomalies
Stage 3: Months 2-5. Migration and HistogenesisNeuronal migration from germinal matrix to the cortex. Cortical organization. Disorders: Heterotopias, agyria-pachygyria, polymicrogyria, vascular malformations, teratomas, phakomatosis.
Stage 4: 5 - 15 months; matures by 3 years. MyelinationInferior to superior; posterior to anterior. Failure: developmental delay, dysmyelinating disease
Chiari malformation + CC agenesis + meningocele + blockvertebra
CONGENITAL ANOMALIES
US, MRI, CT, conventional X-ray, DSA
Underlying vascular processes• Developmental
– aneurysms
– vascular malformations
• Acquired – stenoocclusive lesions
– thromboembolic processes
Cerebrovascular disorders - STROKE
Intracerebral lesions:
–ischaemic
–haemorrhagic
CT, MRI
DISEASES OF CNS
CTA, MRA, DSA, US
Ischaemic infarcts• Initial stage: CT, MR
– „Hyperdense vessel” sign– Early ischaemic signs– CT perfusion:
CBFdefect-CBVdefect=penumbra
• Developing stage• End stage
Cerebrovascular disorders
DISEASES OF CNS
CBVCBF
Cerebrovascular disorders
Ischaemic infarcts – Initial stage: CT, MR
MR: PWI –DWI=penumbra
– Developing stage
– End stage
DWI PWI
Mismatch
DISEASES OF CNS
Ischaemic infarcts• Initial stage• Developing stage: CT, MR
– Oedema -> mass effect– Luxury perfusion
• End stage
Cerebrovascular disorders
DISEASES OF CNS
Ischaemic infarcts• Initial stage• Developing stage• End stage: CT, MR
– Retraction– -> CSF density/signal
Cerebrovascular disorders
DISEASES OF CNS
Cerebrovascular disorders
Haemorrhagic infarcts: CT– Initial stage: method of choice
– Hyperdense, mass effect
– Developing stage: – Density decreases
– End stage: – Nearly CSF density
– Mass effect disappears
DISEASES OF CNS
Cerebrovascular disorders
Haemorrhagic infarcts: MR??– Initial stage: not sensitive
– Developing stage:– Blood degradation products
– End stage
DISEASES OF CNS
Cerebrovascular disorders
Haemorrhagic infarcts : MR
– Initial stage– Developing stage– End stage:
T2W sequences – T2* GRE
DISEASES OF CNS
Cerebrovascular disorders
Underlying processesDevelopmental lesions
– Aneurysms:
• Angiography (CTA/MRA, DSA)
– vascular malformations
DISEASES OF CNS
Cerebrovascular disorders
Underlying processesDevelopmental lesions
– aneurysms
– vascular malformations
• CT,MR
• CTA, MRA, DSA
DISEASES OF CNS
Cerebrovascular disorders
Underlying processesAcquired vascular diseases
– stenoocclusive processes (arteriosclerosis)
• US
• angiography
– thromboembolic processes
DISEASES OF CNS
Cerebrovascular disordersUnderlying processesAcquired vascular diseases
– stenoocclusive processes (arteriosclerosis)
– thromboembolic processes:• Arterial
– Extracranial - US
– Intracranial - CTA, MRA, DSA
• Venous
DISEASES OF CNS
Cerebrovascular disordersUnderlying processesAcquired vascular diseases
– stenoocclusive processes (arteriosclerosis)
– thromboembolic processes:• Arterial
• Venous
– CT, MR
– CTA, MRA, (DSA)
DISEASES OF CNS
INTRACRANIAL TUMOURS - classification
– Extraaxial (non-neurogenic)
• supratentorial
• infratentorial
– Intraaxial (neurogenic)
• supratentorial
• infratentorial
DISEASES OF CNS
Imaging methods
• Plain film radiography• Ultrasonography (US)• Computertomography (CT):
– Conventional CT + contrast material– CTA– CT perfusion
• Magnetic resonance imaging (MRI):– Conventional MRI: different sequences, contrast material– MRA– MRS– DWI/PWI– fMRI
• Digital subtraction angiography (DSA)
Characteristics of tumours - imaging
• Abnormal tissue growth: CT, MRI• Altered vascularisation: perfusion, angiography• Changed metabolism: MRS• Contrast enhancement: CT, MRI + iv. contrast material• Perifocal edema: CT, MRI, MRS• Space-occupying effect: CT, MRI• Hydrocephalus: CT, MRI• Bone lesions: CT, MRI• Multiplicity: CT, MRI
Abnormal tissue growth
• Structure: – homogeneity, – calcification, – cyst, – necrosis– haemorrhage
• Border: – sharp– blurred– irregular e.g.
Changed vascularisation Gr. 3 astrocytoma
Meningioma
Tumor vascularisation– Increased CBV, CBF– Dignity – CBV correlation +– Increased permeability: enhancement– Angio: hypervascularisation
Changed metabolism – MR spectroscopy
Normal brain
Tumor
Cho=cellularity, NAA=neuron integrity, Lac=anaerob metabolism
Changed metabolism
• MR spectroscopy: • Tumor or not tumor • Tumor diff. dg • Grading • Extension (focal, infiltration,
enhancing and non-enhancing, over T2 parts)
• Heterogeneity • Biopsy (high grade parts) • Effect of therapy• Consequencies of therapy(radiation necrosis or recidive tumor)
Contrast enhancement
• Non enhancing
• Enhancing (homogeneous, heterogeneous)
• Partly enhancing tumors
• Special signs: „tail sign”,
closed-opened ring
• Malignity – cm enhancement correlation in a histological group +
Contrast enhancement
• Non enhancing
• Enhancing (homogeneous, inhomogeneous)
• Partly enhancing
• Special signs: „tail sign”,
closed or opened ring
• Malignity – c.m. enhancement
correlation in a histological group +
Perifocal edema
• Vasogenic type• fingerlike
• involving only the white matter
Space-occupying effect
• Edema+tumor– compression/dislocation– herniations
• subfalcial, • transtentorial, • transforaminal
Hydrocephalus
• CSF-producing tumor: • plexus papilloma
• Middle-line tumor• plexus papilloma
• medulloblastoma
• ependymoma
• Meningial tumors: • metastatic,
• haematological tu.
Bone changes
• Lytic
• Sclerotic
• Atrophic
• Destructive lesions
Multiplicity
• Metastases
• Glioblastoma
• Non-tumour diseases
INTRACRANIAL TUMOURS
Neuroimaging = histological diagnosis
INFLAMMATIONS
• Viral
• Bacterial
• Fungal
• Parasitic
• Immune-mediated
• Others
• Brain parenchyma– encephalitis
– cerebritis, abscess
– multiple sclerosis
• Meningitis
• Vasculitis
• Osteomyelitis
Diseases of CNSMRI
INFLAMMATIONS• Brain parenchyma
– encephalitis
• herpes encephalitis
– cerebritis, abscess
– multiple sclerosis
• Meningitis
• Vasculitis
• Osteomyelitis
Diseases of CNS
INFLAMMATIONS• Brain parenchyma
– encephalitis
– cerebritis, abscess
– multiple sclerosis
• Meningitis
• Vasculitis
• Osteomyelitis
Diseases of CNS
INFLAMMATIONS
• Brain parenchyma– encephalitis
– cerebritis, abscess
– multiple sclerosis
• Meningitis
• Vasculitis
• Osteomyelitis
Diseases of CNS
INFLAMMATIONS• Brain parenchyma
– encephalitis
– cerebritis, abscess
– multiple sclerosis
• Meningitis
• Vasculitis
• Osteomyelitis
Diseases of CNS
INFLAMMATIONS• Brain parenchyma
– encephalitis– cerebritis, abscess– multiple sclerosis
• Meningitis– complications:
• hygroma• abscess formation• hydrocephalus• thrombosis
• Vasculitis• Osteomyelitis
Diseases of CNS
TRAUMA
• Open head trauma
(dural tear)– impression fracture
– pneumatocele
– foreign body
– haematoma, edema
– secondary infection
• Closed head trauma
(intact dura)
– epidural haematoma
– subdural haematoma
– contusion
– edema
Diseases of CNS CT
TRAUMA
• Closed head trauma (intact dura mater)– epidural haematoma
– subdural haematoma• acute - hyperdense
• subacute - isodense
• chronic - hypodense
– contusion
– edema
Diseases of CNS
TRAUMA
• Closed head trauma (intact dura mater)– epidural haematoma
– subdural haematoma• acute - hyperdense
• subacute - isodense
• chronic - hypodense
– contusion
– edema
Diseases of CNS
TRAUMA
• Open head trauma (dural
tear)
– impression fracture
– pneumatocele
– foreign body
– haematoma, edema
– secondary infection
Diseases of CNS
TRAUMA• Open head trauma (dural
tear)
– impression fracture
– pneumatocele
– foreign body
– haematoma, edema
– infection
Diseases of CNS