Diagnosing Vascular Cranial Diseases Using Compted Tomography

Dept of Diagnostic & Interventional Radiology, University Clinic, Johann Wolfgang Goethe-University Frankfurt/Main, Germany

Matthias KerlMatthias Kerl

Institute for Diagnostic and Institute for Diagnostic and

Interventional RadiologyInterventional Radiology

Johann Wolfgang Goethe Johann Wolfgang Goethe

University University

Frankfurt am MainFrankfurt am Main

Diagnosing Vascular Cranial Diseases Using Compted Tomography


Symptomatic patients1:

• High benefit of CEA for patients with >70% stenosis

• Moderate benefit of CEA for patients with 50-70% stenosis

Asymptomatic patients2:

• Small benefit in terms of absolute risk

1Rothwell PM, Lancet (2003) 361:107–1162Moore WS, Circulation (1995) 91:556–579

Standard of reference

• DSA Poor correlation to postmortem findings1

• Vascular ultrasound Poor in assessment of filiform stenoses

Calcifications cancel the depiction of the vessel lumen

1Schulte-Altedorneburg G, J Neurol (2005) 252 : 575–5821Polak JF, Radiology (1998) 209:288–289

Standard of reference

• DSA Poor correlation to postmortem findings1

• Vascular ultrasound1

Poor in assessment of filiform stenoses

Calcifications cancel the depiction of the vessel lumen

CTA of the Carotids: BackgroundCTA of the Carotids: Background

• Unable to display vascular wall / surrounding soft tissue• In complex stenoses >1 angiographic projections needed

But: • Excellent display of vessel lumen regardless of blood flow

• Excellent reproducibility • Excellent portray of arterial anatomy (Aortic arch to cerebral vessels)


CTA of the Carotids: BackgroundCTA of the Carotids: Background

Alternative non-invasiveprocedures:

• CTA

• Filling techniques- First-pass technique- Passage of a bolus of CM through imaged volume- Depict lumen & surrounding arterial wall / soft tissues

• „Flow-dependent“ techniquesUS (Doppler, duplex / color-flow)MRA (TOF / PCA)Measure blood must through volume of interest

MRA CTA


• CTA

(1) x-ray tubes with adequate photon flux & cooling capacity (2) detector technology allowing simultaneous gathering of multiple thin axial profile data sets (3) continuous rotating x-ray tubes with continuous table travel (helical or spiral technology


• CTA


CTA of the Carotids: MDCTCTA of the Carotids: MDCT


• CTA

Spiral-CT

4-row MDCT

64-row MDCT

IsotropicVoxel


CTA and MRA of the Carotids: MDCTCTA and MRA of the Carotids: MDCT


• CTA


CTA of the Carotids: MDCTCTA of the Carotids: MDCT


• CTA


CTA of the Carotids: Minimal requirementsCTA of the Carotids: Minimal requirements

>>4-slice Multidetector-row CT4-slice Multidetector-row CTScanning • >4 x 2.5 mm collimation• >0.5 sec rotation time• 100mAs / 120kV• CM:120ml @ 3ml/s

300mgI/ml bolus triggering / test bolus

Image Reconstruction• slice tickness / increment

• 3/3mm• 3/1.5mm (MPR)

• medium soft tissue kernel B30f


64-slice MDCT64-slice MDCT • 64 x 0.6mm collimation• z-flying focal spot technique• 0.33sec rotation time• AATCM• 72mAs(base)

• 120kV • CM: 90ml 400mgI/ml

30ml @ 4.5ml/s60ml @ 2.5ml/s30ml Saline @ 2.5ml/sInfusion via right arm (artefacts) Bolus triggering (160 HU / aA)

• ECG triggering @ Stanford Type A

CTA of the Carotids: Recommended scan protocolCTA of the Carotids: Recommended scan protocol


64-slice MDCT64-slice MDCT • 64 x 0.6mm collimation• z-flying focal spot technique• 0.33sec rotation time• AATCM• 72mAs(base)

• 120kV • CM: 90ml 400mgI/ml

30ml @ 4.5ml/s60ml @ 2.5ml/s30ml Saline @ 2.5ml/sInfusion via right arm (artefacts) Bolus triggering (160 HU / aA)

• ECG triggering @ Stanford Type A

Single BolusSplit Bolus

CTA of the Carotids: Recommended scan protocolCTA of the Carotids: Recommended scan protocol


CT Angiography - HeadCT Angiography - HeadCircle of WillisCircle of Willis

AneurysmsAneurysms

Vascular MalformationsVascular Malformations


3-mm aneurysm in MCA, at the origin of L’t anterior temporal artery.


2-mm aneurysm at R’t pericallosal artery.


Ideal imaging modality for aneurysm detection and characterization:Non-invasive.Easy to perform.Reproducible.Readily available.Minimal complications.High degree of accuracy.


Intracerebral haemorrhage on CTIntracerebral haemorrhage on CT

Is always seen apparent immediately lasts 1 week then disappears and looks like

an infarct


Intracerebral HaemorrhageIntracerebral Haemorrhage Usually caused by

hypertension thickening & weakening of

walls of small arteries/arterioles

formation of small aneurysms rupture produces a large

blood filled cavity that acts as a SOL

typically basal ganglia or thalamus


Ischaemic stroke on CTIschaemic stroke on CT

Infarcts seen as areas of hypodensity

become more obvious as time progresses

small infarcts appear later than large ones

overall, 40% strokes have normal CT

posterior fossa difficult


Cerebral InfarctionCerebral Infarction Infarction is caused by failure of blood

flow to a region damage to the brain is due to:

ischaemia oedema surrounding the ischaemic

area sources of occlusion of vessels:

thrombosis of small vessels - hypertensive lipohyalinosis - lacunar infarcts

thrombosis of larger vessels embolus from extracranial vessels or

heart


Question 1: Mr YQuestion 1: Mr Y

A 72 year old lady with known bladder cancer (transitional cell carcinoma) presents with mild left sided weakness.

CT scan


What’s the diagnosis?What’s the diagnosis?


What’s the diagnosis?What’s the diagnosis?

Right frontal lesion is a primary intracerebral haemorrhage stroke

The left frontal lesion is an incidental meningioma

Lessons

Stroke affects older people and co-morbidity is common

About 10% of all stroke is due to primary intracerebral haemorrhage


Pathology of stroke can now be reliably established by CT scanning done within hours/days of the event

Cerebral infarction 80%

Primary intracerebral haemorrhage 10%

Subarachnoid haemorrhage 5%

Unknown 5%

Sudlow & Warlow 1997

Systematic review of world-wide incidence studies


Question 2Question 2

64 year old man was driving his car and he suddenly lost power in his right arm and leg

He had no headache

No loss of consciousness

Called for help and son brought him to casualty

No significant medical history


On examinationOn examination

Looked well

Blood pressure 200/120 mmHg

Normal language

Slurred speech

Complete weakness affecting his right face, arm and leg

No hemianopia


Is this a stroke?Is this a stroke?


Yes! Due to a Lacunar InfarctionYes! Due to a Lacunar Infarction


Question 3: 85 year old ladyQuestion 3: 85 year old lady

Presents with a sudden onset of dizziness and headache

On examination she had nystagmus

Six hours after admission started to complain of worsening headache

24 hours later was unconscious

Is this a stroke?


Yes! A cerebellar

haemorrhage with acute

hydrocephalus

Yes! A cerebellar

haemorrhage with acute

hydrocephalus


Question 4Question 4

Mrs X 69 years old

Developed Right hemiparesis and aphasia during breakfast (9am)

Husband called GP and sent immediately to A & E department


Severe (0/5) right face, arm and leg weakness

Dyspraxia (disorganised movement of body)

Aphasic (no understanding or expression of language)



Yes! Dense MCA sign indicating thrombus in the left MCA


Thank you!

Diagnosing Vascular Cranial Diseases Using Compted Tomography

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