CTA - COX Case of the Day

daughterduckUrban and Civil

Nov 15, 2013 (3 years and 6 months ago)

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


Matthias Kerl


Institute for Diagnostic and

Interventional Radiology



Johann Wolfgang Goethe

University


Frankfurt am Main

Diagnosing Vascular
Cranial Diseases Using
Compted Tomography

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

Symptomatic patients
1
:




High benefit of CEA for


patients with
>
70% stenosis




Moderate benefit of CEA for


patients with 50
-
70% stenosis



Asymptomatic patients
2
:





Small benefit in terms of absolute risk



1
Rothwell PM,
Lancet

(2003) 361:107

116

2
Moore WS, Circulation (1995) 91:556

579

Standard of reference




DSA


Poor correlation to


postmortem findings
1





Vascular ultrasound


Poor in assessment of


filiform stenoses



Calcifications cancel the


depiction of the vessel


lumen

1
Schulte
-
Altedorneburg G, J Neurol (2005) 252 : 575

582

1
Polak JF, Radiology (1998) 209:288

289

Standard of reference




DSA


Poor correlation to


postmortem findings
1





Vascular ultrasound
1


Poor in assessment of


filiform stenoses



Calcifications cancel the


depiction of the vessel


lumen

CTA 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)

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

CTA of the Carotids:
Background

Alternative non
-
invasive

procedures:




CTA





Filling techniques


-

First
-
pass technique


-

Passage of a bolus of CM through imaged volume


-

Depict lumen & surrounding arterial wall / soft tissues




„Flow
-
dependent“ techniques


US (Doppler, duplex / color
-
flow)


MRA (TOF / PCA)


Measure blood must through volume of interest


MRA

CTA

Alternative non
-
invasive

procedures:




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

Alternative non
-
invasive

procedures:




CTA



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

CTA of the Carotids:
MDCT

Alternative non
-
invasive

procedures:




CTA




Spiral
-
CT

4
-
row MDCT

64
-
row MDCT

Isotropic

Voxel

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

CTA and MRA of the Carotids:
MDCT

Alternative non
-
invasive

procedures:




CTA



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

CTA of the Carotids:
MDCT

Alternative non
-
invasive

procedures:




CTA





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

CTA of the Carotids:
Minimal requirements

>
4
-
slice Multidetector
-
row CT

Scanning



>
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

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

64
-
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/s


60ml @ 2.5ml/s


30ml Saline @ 2.5ml/s


Infusion via right arm (artefacts)


Bolus triggering (160 HU / aA)



ECG triggering @ Stanford Type A



CTA of the Carotids:
Recommended scan protocol

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

64
-
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/s


60ml @ 2.5ml/s


30ml Saline @ 2.5ml/s


Infusion via right arm (artefacts)


Bolus triggering (160 HU / aA)



ECG triggering @ Stanford Type A



Single Bolus

Split Bolus

CTA of the Carotids:
Recommended scan protocol

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

CT Angiography
-

Head

Circle of Willis

Aneurysms

Vascular Malformations

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


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

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


2
-
mm aneurysm at R’t
pericallosal artery.

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

Ideal imaging modality for aneurysm detection and
characterization:


Non
-
invasive.


Easy to perform.


Reproducible.


Readily available.


Minimal complications.


High degree of accuracy.

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

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

Intracerebral haemorrhage on CT


Is always seen


apparent immediately


lasts 1 week


then disappears and looks like
an infarct

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

Intracerebral 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

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

Ischaemic 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

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

Cerebral 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

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

Question 1: Mr Y

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


CT scan

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

What’s the diagnosis?

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

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

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

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

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

Question 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

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

On examination

Looked well

Blood pressure 200/120 mmHg

Normal language

Slurred speech

Complete weakness affecting his right face, arm and leg

No hemianopia


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

Is this a stroke?

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

Yes! Due to a Lacunar Infarction

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

Question 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?

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

Yes! A
cerebellar
haemorrhage
with acute
hydrocephalus

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

Question 4

Mrs X

69 years old

Developed Right hemiparesis and aphasia during
breakfast (9am)

Husband called GP and sent immediately to A & E
department


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

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

Dyspraxia (disorganised movement of body)

Aphasic (no understanding or expression of language)

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

Is this a stroke?

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

Is this a stroke?

Yes!


Dense MCA
sign indicating
thrombus in the
left MCA

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

Thank you!