NEURORADIOLOGY Part I Vörös Erika University of Szeged Department of Radiology SZEGED
DISEASES OF CNS BRAIN Developmental anomalies Cerebrovascular disorders Tumours Inflammatory diseases Trauma
DISEASES OF CNS BRAIN IMAGING METHODS Plain film radiography Ultrasonography (US) Computer tomography (CT) Magnetic resonance imaging (MRI) Digital subtraction angiography (DSA) (Cisternography, ventriculography)
DISEASES OF CNS DEVELOPMENTAL ANOMALIES CNS 9.3%
DEVELOPMENTAL ANOMALIES:(due to some NOXA in the fetal life) Stage 1: Weeks 3-4 Dorsal Induction: Formation and Closure of the Neural Tube Three phases: Neurulation, canalization, retrogressive differentiation Failure: Anencephaly, Cephalocele, Chiari, Spinal dysraphism Stage 2: Weeks 5-10 Ventral Induction: Formation of the Brain Segments and Face Three 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 Histogenesis Neuronal 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. Myelination Inferior to superior; posterior to anterior. Failure: developmental delay, dysmyelinating disease
CONGENITAL ANOMALIES US, MRI, CT, conventional X-ray, DSA Chiari malformation + CC agenesis + meningocele + blockvertebra
DISEASES OF CNS Cerebrovascular disorders - STROKE CT, CTA, MRA, DSA, US MRI Intracerebral lesions: ischaemic haemorrhagic Underlying vascular processes Developmental aneurysms vascular malformations Acquired stenoocclusive lesions thromboembolic processes
DISEASES OF CNS Cerebrovascular disorders Ischaemic infarcts Initial stage: CT, MR Hyperdense vessel sign Early ischaemic signs CT perfusion: CBFdefect-CBVdefect=penumbra Developing stage End stage CBF CBV
DISEASES OF CNS Cerebrovascular DWI PWI disorders Ischaemic infarcts Initial stage: CT, MR MR: PWI DWI=penumbra Developing stage End stage Mismatch
DISEASES OF CNS Cerebrovascular disorders Ischaemic infarcts Initial stage Developing stage: CT, MR Oedema -> mass effect Luxury perfusion End stage
DISEASES OF CNS Cerebrovascular disorders Ischaemic infarcts Initial stage Developing stage End stage: CT, MR Retraction -> CSF density/signal
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 processes Developmental lesions Aneurysms: Angiography (CTA/MRA, DSA) vascular malformations
DISEASES OF CNS Cerebrovascular disorders Underlying processes Developmental lesions aneurysms vascular malformations CT,MR CTA, MRA, DSA
DISEASES OF CNS Cerebrovascular disorders Underlying processes Acquired vascular diseases stenoocclusive processes (arteriosclerosis) US angiography thromboembolic processes
DISEASES OF CNS Cerebrovascular disorders Underlying processes Acquired vascular diseases stenoocclusive processes (arteriosclerosis) thromboembolic processes: Arterial Extracranial - US Intracranial - CTA, MRA, DSA Venous
DISEASES OF CNS Cerebrovascular disorders Underlying processes Acquired 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
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 Tumor vascularisation Increased CBV, CBF Dignity CBV correlation + Increased permeability: enhancement Angio: hypervascularisation Meningioma
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
Diseases of CNS MRI INFLAMMATIONS Viral Bacterial Fungal Parasitic Immune-mediated Others Brain parenchyma encephalitis cerebritis, abscess multiple sclerosis Meningitis Vasculitis Osteomyelitis
Diseases of CNS 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 Closed head trauma (intact dura) epidural haematoma CT Open head trauma (dural tear) impression fracture pneumatocele subdural haematoma foreign body contusion haematoma, edema edema secondary infection
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 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