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