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Case 1254

Carotid artery stenosis - evaluation with multislice CT

Author(s)
B. Tomandl, B. Stemper, M. Lell
 
Patient
male, 64 year(s)

Clinical History

Right hemispheric stroke

Imaging Findings

The patient was admitted with left-sided hemiparesis. An initial CT scan showed no early signs of ischaemic stroke or haemorrhage. CT-perfusion (CTP) did not reveal a perfusion deficit. In addition, we performed CT-angiography (CTA) of the extracranial and intracranial blood vessels responsible for brain perfusion. CTA showed a severe stenosis of the right internal carotid artery (ICA).

Discussion

CT is still the method of choice for the fast and reliable evaluation of patients with stroke. The first step is to exclude intracranial haemorrhage. Non-enhanced CT (NECT) performed within the first six hours after onset of symptoms may show subtle "early signs" of ischaemic stroke, indicating irreversible brain damage. If irreversible damage of brain tissue has not yet occurred and the patient is admitted within four hours after the onset of symptoms, thrombolysis is a therapeutic option. However, NECT fails to reliably differentiate between brain with sufficient and insufficient perfusion. This differentiation is essential in deciding whether the patient can undergo thrombolysis. Thrombolysis might be harmful if the patient presents with large areas of non-perfused brain. CT-perfusion (CTP) was introduced to improve the evaluation of insufficiently perfused brain, so-called "tissue at risk". Evaluation of the large extracranial and intracranial vessels assuring brain perfusion can be performed safely and non-invasively using CT-angiography (CTA).

In this patient, neither CTP nor NECT - performed immediately after admission and repeated 24 hours later - showed any evidence of ischaemic stroke. In contrast, CTA revealed a high degree stenosis of the right ICA as a probable reason for the patients' symptoms.

In conclusion, with the recent introduction of multislice CT, comprehensive imaging of stroke became possible. Multislice CT combines the information of non-enhanced CT (NECT), CTP and CTA within 15 minutes.

Final Diagnosis

Carotid artery stenosis
 

MeSH

  1. Carotid Stenosis [C10.228.140.300.200.360]
    Narrowing or stricture of the internal, common, or external carotid artery, most often as a result of atherosclerotic plaque formation. Ulcerations may form in atherosclerotic plaques and induce thrombus formation. Platelet or cholesterol emboli may arise from stenotic carotid lesions and induce a transient ischemic attack (ISCHEMIC ATTACK, TRANSIENT) or CEREBROVASCULAR ACCIDENT. Emboli which travel to the eye may manifest as AMAUROSIS FUGAX (temporary blindness). (From Adams et al., Principles of Neurology, 6th ed, pp822-3)

References

  1. [1]
    von Kummer R, Bourquain H, Bastianello S, Bozzao L, Manelfe C, Meier D, Hacke W. Early prediction of irreversible brain damage after ischemic stroke at CT. Radiology. 2001 Apr;219(1):95-100..

  2. [2]
    Koenig M, Kraus M, Theek C, Klotz E, Gehlen W, Heuser L. Quantitative assessment of the ischemic brain by means of perfusion-related parameters derived from perfusion CT. Stroke. 2001 Feb;32(2):431-7..

  3. [3]
    Randoux B, Marro B, Koskas F, Duyme M, Sahel M, Zouaoui A, Marsault C. Carotid artery stenosis: prospective comparison of CT, three-dimensional gadolinium-enhanced MR, and conventional angiography. Radiology. 2001 Jul;220(1):179-85..

Citation

B. Tomandl, B. Stemper, M. Lell (2001, Nov 12).
Carotid artery stenosis - evaluation with multislice CT, {Online}.
URL: http://www.eurorad.org/case.php?id=1254
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  • Published 12.11.2001
  • DOI 10.1594/EURORAD/CASE.1254
  • Section Cardiovascular
  • Case-Type Clinical Case
  • Difficulty Senior
  • Views 533
  • Language(s)
  • Figure 1
    NECT

    Initial NECT, 3 hours after the onset of symptoms, showing no early signs of ischaemic stroke.

     
  • Figure 2
    CT-Perfusion
    a b  

    CTP: Colour map of cerebral blood volume showing no evidence of ischaemia.

    CTP: Colour map of time to peak showing no evidence of ischaemia and no areas of delayed enhancement.

     
  • Figure 3
    CT-Angiography
    a b c d  

    MIP-Visualization of the right carotid bifurcation showing severe stenosis of the ICA.

    Curved MPR demonstrates both the residual lumen and the intraluminal soft plaque.

    Direct volume rendering illustrates the carotid stenosis in relation to the bony structures of the skull.

    Axial slice image allows a precise evaluation of the degree of stenosis of the right ICA (arrow).

     
Figure 1

NECT

Initial NECT, 3 hours after the onset of symptoms, showing no early signs of ischaemic stroke.
 
Figure 2

CT-Perfusion

Figure 2a
CTP: Colour map of cerebral blood volume showing no evidence of ischaemia.
 
Figure 2b
CTP: Colour map of time to peak showing no evidence of ischaemia and no areas of delayed enhancement.
 
Figure 3

CT-Angiography

Figure 3a
MIP-Visualization of the right carotid bifurcation showing severe stenosis of the ICA.
 
Figure 3b
Curved MPR demonstrates both the residual lumen and the intraluminal soft plaque.
 
Figure 3c
Direct volume rendering illustrates the carotid stenosis in relation to the bony structures of the skull.
 
Figure 3d
Axial slice image allows a precise evaluation of the degree of stenosis of the right ICA (arrow).
 
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