NEURORADIOLOGY
Part I
Vörös Erika
University of Szeged
Department of Radiology
SZEGED
BRAIN IMAGING METHODS
• Plain film radiography
• Ultrasonography (US)
• Computer tomography (CT)
• Magnetic resonance imaging (MRI)
• Digital subtraction angiography (DSA)
• (Cisternography, ventriculography)
Plain film radiography
– trauma
– foreign bodies
– bone lesions
– calcifications
IMAGING METHODS
Ultrasonography
– newborn, infant
– intracranial lesions
(transfontanelle)
– vascular structures
Doppler US
IMAGING METHODS
Ultrasonography
– Doppler (duplex, color-
coded)
– vascular structures
- extracranial, transcranial
IMAGING METHODS
Computer tomography
– direct method - density
differences (hypo-, iso- or
hyperdense lesions)
– axial and reformatted pictures
– contrast material enhancement
– CT angiography
– Special techniques
IMAGING METHODS
Computer tomography
– direct method
– axial and reformatted images–
spiral/helical CT
– contrast material enhancement
– CT angiography
– Special techniques
IMAGING METHODS
Computer tomography
– direct method
– axial and reformatted pictures
– contrast material enhancement
(vessels, blood-brain barrier
damage)
– CT angiography
– Special techniques
IMAGING METHODS
Computer tomography
– direct method
– axial and reformatted pictures
– contrast material enhancement
– CT angiography
• helical CT
– Special techniques
IMAGING METHODS
Computer tomography
– direct method
– axial and reformatted pictures
– contrast material enhancement
– CT angiography
– Special techniques
• CT perfusion:
CBF, CBV, MTT, TTP
IMAGING METHODS
IMAGING METHODS
Computer tomography
Indications
– bone lesions
– calcifications
– fresh blood
– tumours
– infarcts
– trauma
Unfavorable
–near the bones
– in posterior fossa
–adjacent to the sella
–metallic material
MRI
– direct method –
– signal intensity differences
(hypo-, iso- or hyperintensive lesions)
– multiplanar modality
– different sequences (T1W, T2W, FLAIR, …)
– contrast material enhancement
(vessels, blood-brain barrier damage)
– MR angiography
– Special MR techniques
IMAGING METHODS
MRI – direct method
– multiplanar modality
– different sequences
– contrast material enhancement
– MR angiography:
TOF, PC, CE-MRA, dynamic MRA
– Special MR techniques:
SWI, DWI, PWI, DTI, fMRI,
MR spectroscopy,e.g.
IMAGING METHODS
MRI
Indications
– developmental anomalies
– tumours
– infarcts
– inflammations
– subtle lesions etc.
Unfavorable
–calcification,
–bone lesions (non-organic components)
–metallic material
IMAGING METHODS
DSA
– invasive, catheter method - for
vascular structures
– contrast material, radiation
dose
– best spatial and temporal
resolution
– 3 D imaging
– interventional procedures!
IMAGING METHODS
DSA
Indications
– preoperative
– differential diagnosis
– intervention
Diagnostic role
Non-invasive angiographies!
IMAGING METHODS
Developmental anomalies
MRI, CT, plain film, DSA
– arachnoid cyst
– Chiari malformations
– etc.
DISEASES OF CNS
Underlying vascular processes • Developmental
– aneurysms
– vascular malformations
• Acquired
– stenoocclusive lesions
– thromboembolic processes
Cerebrovascular disorders - STROKE
Intracerebral lesions:
–ischaemic
–haemorrhagic
CT, MRI, US, DSA
DISEASES OF CNS
Ischaemic infarcts
• Initial stage: CT-CTP, MR
– „Hyperdense arterial” sign
– Early ischaemic signs
– CBFdefect-CBVdefect=PENUMBRA
• Developing stage
• End stage
Cerebrovascular disorders
DISEASES OF CNS
CBV CBF
Cerebrovascular disorders
Ischaemic infarcts
– Initial stage: CT, MR-DWI,PWI
• PWIdef –DWIdef=penumbra
– Developing stage
– End stage
PWI DWI
Mismatch
DISEASES OF CNS
Ischaemic infarcts
• Initial stage
• Developing stage: CT, MR
– Cytotoxic oedema -> mass effect
– Contrast enhancement
• 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
Ischaemic infarcts
• Territorial – a larger artery
occlusion
• Lacunar – small perforator occlusion
• Diffuse white matter – small vessels
disease
• Border zones – decresed perfusion at
the border of the supplying territory
Cerebrovascular disorders
DISEASES OF CNS
Cerebrovascular disorders
Haemorrhagic infarcts: CT
• Initial stage:
– Hyperdense, mass effect
• Developing stage:
– Continuous decrease of density
• End stage:
– Nearly CSF density
– Mass effect disappears
DISEASES OF CNS
Cerebrovascular disorders
Haemorrhagic infarcts: MR
– Initial stage: SWI
– Developing stage:
– Blood degradation products:
high signal
– End stage
DISEASES OF CNS
Cerebrovascular disorders Haemorrhagic infarcts : MR
– Initial stage
– Developing stage
– End stage:
T2W sequences –T2* GRE, SWI:
low signal
DISEASES OF CNS
Cerebrovascular disorders
Haemorrhagic infarcts
– Basal ganglia - hypertension
– Lobar – AVM, tumor, others
DISEASES OF CNS
Cerebrovascular disorders
Underlying processes
Developmental lesions
Aneurysms -> SAH
• CT, MR
• Angiography (CTA/MRA, DSA)
– vascular malformations
DISEASES OF CNS
Cerebrovascular disorders
Underlying processes Developmental lesions
– aneurysms – vascular malformations: AVM
(cavernoma, teleangiectasia) – Haemorrhage, ischaemia
• CT • MR • Angiography (CTA, MRA, DSA)
DISEASES OF CNS
Cerebrovascular disorders
Underlying processes
Acquired vascular diseases
– stenoocclusive processes
(artherosclerosis)
• US, CTA, MRA
• angiography
– thromboembolic processes
DISEASES OF CNS
Cerebrovascular disorders
Underlying processes
Acquired vascular diseases
– stenoocclusive processes
(arteriosclerosis)
• US, CTA, MRA
• Angiography/stentig
– 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
Cerebrovascular disorders
Thrombectomy • Arterial thrombus: ICA,
ACA, ACM, AB • Venous sinus thrombus
DISEASES OF CNS