Contrast-enhanced MR angiography for carotid disease

Objective: To compare contrast-enhanced MR angiography (CEMRA) with intra-arterial digital subtraction angiography (DSA) for evaluating carotid stenosis. Methods: A total of 167 consecutive symptomatic patients, scheduled for DSA following screening duplex ultrasound (DUS), were prospectively recruited to have CEMRA. Three independent readers reported on each examination in a blinded and random manner. Agreement was assessed using the Bland-Altman method. Diagnostic and potential clinical impact of CEMRA was evaluated, singly and in combination with DUS. Results: CEMRA tended to overestimate stenosis by a mean bias ranging from 2.4 to 3.8%. A significant part of the disagreement between CEMRA and DSA was directly caused by interobserver variability. For detection of severe stenosis, CEMRA alone had a sensitivity of 93.0% and specificity of 80.6%, with a diagnostic misclassification rate of 15.0% (n = 30). More importantly, clinical decision-making would, however, have been potentially altered only in 6.0% of cases (n = 12). The combination of concordant DUS and CEMRA reduced diagnostic misclassification rate to 10.1% (n = 19) at the expense of 47 (24.9%) discordant cases needing to proceed to DSA. An intermediate approach of selective DUS review resulted in a marginally worse diagnostic misclassification rate of 11.6% (n = 22) but with only 6.8% of discordant cases (n = 13). Conclusions: DSA remains the gold standard for carotid imaging. The clinical misclassification rate with CEMRA, however, is acceptably low to support its safe use instead of DSA. The appropriateness of combination strategies depends on institutional choice and cost-effectiveness issues.

[1]  J. Wardlaw,et al.  How does the degree of carotid stenosis affect the accuracy and interobserver variability of magnetic resonance angiography? , 2001, Journal of neurology, neurosurgery, and psychiatry.

[2]  D. Birchall,et al.  Evaluation of Cross-Sectional Luminal Morphology in Carotid Atherosclerotic Disease by Use of Spiral CT Angiography , 2001, Stroke.

[3]  George Tomlinson,et al.  Neurologic complications of cerebral angiography: prospective analysis of 2,899 procedures and review of the literature. , 2003, Radiology.

[4]  C Marsault,et al.  Carotid artery stenosis: prospective comparison of CT, three-dimensional gadolinium-enhanced MR, and conventional angiography. , 2001, Radiology.

[5]  S. Pendlebury,et al.  Critical appraisal of the design and reporting of studies of imaging and measurement of carotid stenosis. , 2000, Stroke.

[6]  C. Bartolozzi,et al.  Contrast-Enhanced Three-Dimensional Magnetic Resonance Angiography of Atherosclerotic Internal Carotid Stenosis as the Noninvasive Imaging Modality in Revascularization Decision Making , 2003, Stroke.

[7]  E Berry,et al.  The cost-effectiveness of magnetic resonance angiography for carotid artery stenosis and peripheral vascular disease: a systematic review. , 2002, Health technology assessment.

[8]  Paul J. Nederkoorn,et al.  Duplex Ultrasound and Magnetic Resonance Angiography Compared With Digital Subtraction Angiography in Carotid Artery Stenosis: A Systematic Review , 2003, Stroke.

[9]  D. Kallmes,et al.  Specificity of MR angiography as a confirmatory test of carotid artery stenosis. , 1996, AJNR. American journal of neuroradiology.

[10]  D. Altman,et al.  STATISTICAL METHODS FOR ASSESSING AGREEMENT BETWEEN TWO METHODS OF CLINICAL MEASUREMENT , 1986, The Lancet.

[11]  P. Humphrey,et al.  Variability in measurement of extracranial internal carotid artery stenosis as displayed by both digital subtraction and magnetic resonance angiography: an assessment of three caliper techniques and visual impression of stenosis. , 1996, Stroke.

[12]  J. Norris,et al.  Vascular imaging before carotid endarterectomy. , 2003, Stroke.

[13]  S J Riederer,et al.  Carotid artery: elliptic centric contrast-enhanced MR angiography compared with conventional angiography. , 2001, Radiology.

[14]  Erik Buskens,et al.  Preoperative Diagnosis of Carotid Artery Stenosis: Accuracy of Noninvasive Testing , 2002, Stroke.

[15]  T. Magee,et al.  Carotid duplex imaging: variation and validation , 2000, The British journal of surgery.

[16]  Allan J. Fox,et al.  Significance of Plaque Ulceration in Symptomatic Patients With High‐Grade Carotid Stenosis , 1994, Stroke.

[17]  J. Wardlaw,et al.  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 , 2002, Journal of neurology, neurosurgery, and psychiatry.

[18]  D. Sackett,et al.  Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. North American Symptomatic Carotid Endarterectomy Trial Collaborators. , 1998, The New England journal of medicine.

[19]  J. Slattery,et al.  Randomised trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European Carotid Surgery Trial (ECST) , 1998, The Lancet.

[20]  G. Donnan,et al.  Is carotid angiography necessary? Editors disagree , 2003 .

[21]  J. Eastwood,et al.  Contrast-Enhanced Magnetic Resonance Angiography of Carotid Arteries: Utility in Routine Clinical Practice , 2002, Stroke.

[22]  Markus Horn,et al.  Preoperative evaluation of carotid artery stenosis: comparison of contrast-enhanced MR angiography and duplex sonography with digital subtraction angiography. , 2003, AJNR. American journal of neuroradiology.

[23]  M. Eliasziw,et al.  Analysis of pooled data from the randomised controlled trials of endarterectomy for symptomatic carotid stenosis , 2003, The Lancet.

[24]  J. Debbins,et al.  Arterial phase carotid and vertebral artery imaging in 3D contrast‐enhanced MR angiography by combining fluoroscopic triggering with an elliptical centric acquisition order , 1998, Magnetic resonance in medicine.

[25]  G. Schroth,et al.  Contrast-enhanced 3D MR angiography of the carotid artery: comparison with conventional digital subtraction angiography. , 2002, AJNR. American journal of neuroradiology.

[26]  C. Athanasoulis,et al.  Preoperative imaging of the carotid bifurcation. Current trends. , 2000, International angiology : a journal of the International Union of Angiology.

[27]  Juan Alvarez-Linera,et al.  Prospective evaluation of carotid artery stenosis: elliptic centric contrast-enhanced MR angiography and spiral CT angiography compared with digital subtraction angiography. , 2003, AJNR. American journal of neuroradiology.

[28]  P. Nederkoorn,et al.  Time-of-flight MR angiography of carotid artery stenosis: does a flow void represent severe stenosis? , 2002, AJNR. American journal of neuroradiology.

[29]  A. Fox,et al.  Accuracy and prognostic consequences of ultrasonography in identifying severe carotid artery stenosis. North American Symptomatic Carotid Endarterectomy Trial (NASCET) Group. , 1995, Stroke.

[30]  J. Brunberg,et al.  3D gadolinium-enhanced MR angiography of the carotid arteries. , 1996, Magnetic resonance imaging.

[31]  D. Rennie,et al.  Towards complete and accurate reporting of studies of diagnostic accuracy: the STARD initiative , 2003, BMJ : British Medical Journal.

[32]  L. Goldstein,et al.  Clinical carotid endarterectomy decision making , 2001, Neurology.

[33]  J. Bamford,et al.  Use of magnetic resonance angiography to select candidates with recently symptomatic carotid stenosis for surgery: systematic review , 2002, BMJ : British Medical Journal.

[34]  P. Nederkoorn,et al.  Overestimation of carotid artery stenosis with magnetic resonance angiography compared with digital subtraction angiography. , 2002, Journal of vascular surgery.