rss
J Neurol Neurosurg Psychiatry 2002;73:21-28 doi:10.1136/jnnp.73.1.21
  • Paper

Outcome, observer reliability, and patient preferences if CTA, MRA, or Doppler ultrasound were used, individually or together, instead of digital subtraction angiography before carotid endarterectomy

  1. S G Patel1,
  2. D A Collie1,
  3. J M Wardlaw2,
  4. S C Lewis2,
  5. A R Wright3,
  6. R J Gibson1,
  7. R J Sellar1
  1. 1Department of Neuroradiology, University of Edinburgh, Western General Hospital, Edinburgh, UK
  2. 2Department of Clinical Neurosciences, University of Edinburgh
  3. 3Department of Radiology, St Mary's Hospital, London W2, UK
  1. Correspondence to:
 Professor J M Wardlaw, Bramwell Dott Building, Department of Clinical Neurosciences, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK;
 jmw{at}skull.dcn.ed.ac.uk
  • Received 18 December 2000
  • Accepted 18 March 2002
  • Revised 15 March 2002

Abstract

Objectives: To evaluate the accuracy of routinely available non-invasive tests (spiral computed tomographic angiography (CTA), time of flight magnetic resonance angiography (MRA), and colour Doppler ultrasound (DUS)), individually and together, compared with intra-arterial digital subtraction angiography (DSA) in patients with symptomatic tight carotid stenosis; and to assess the effect of substituting non-invasive tests for DSA on outcome, interobserver variability, and patient preference.

Methods: Patients referred from a neurovascular clinic were subjected prospectively to DUS imaging. The operator was blind to symptoms. Patients with a tight carotid stenosis on the symptomatic side were admitted for DSA. CTA and MRA were performed during the admission. The CTA, MRA, and DSA films were each read independently by two of six experienced radiologists, blind to all other data.

Results: 67 patients were included (34 had all four imaging procedures). DUS, CTA, and MRA all agreed with DSA in the diagnosis of operable v non-operable disease in about 80% of patients. CTA tended to underestimate (sensitivity 0.65, specificity 1.0), MRA to overestimate (sensitivity 1.0, specificity 0.57), and DUS to agree most closely with (sensitivity 0.85, specificity 0.71) the degree of stenosis as shown by DSA. When using any two of the three non-invasive tests in combination, adding the third if the first two disagreed would result in very few misdiagnoses (about 6%). MRA had similar interobserver variability to CTA (both worse than DSA). Patients preferred CTA over MRA and DSA.

Conclusions: DUS, CTA, and MRA all show similar accuracy in the diagnosis of symptomatic carotid stenosis. No technique on its own is accurate enough to replace DSA. Two non-invasive techniques in combination, and adding a third if the first two disagree, appears more accurate, but may still result in diagnostic errors.

Footnotes

    This Article

    1. Abstract
    2. Full text
    3. PDF

    Responses

    1. Submit a response
    2. No responses published

    Register for free content

    The full back archive is now available for all BMJ Journals. Institutional subscribers may access the entire archive as part of their subscription. Personal subscribers will also have access to all content when logged in. Non-subscribers who register have free access to all articles published before 2006 right back to volume 1 issue 1. Register here to access the free archive of all BMJ Journals.

    Don't forget to sign up for content alerts so you keep up to date with all the articles as they are published.

    BMJ Careers - Latest neurology and neurosurgery jobs