Contrast-enhanced MR angiography is not more accurate than unenhanced 2D time-of-flight MR angiography for determining ≤70% internal carotid artery stenosis

L. S. Babiarz, J. M. Romero, E. K. Murphy, B. Brobeck, P. W. Schaefer, R. G. González, M. H. Lev

Research output: Contribution to journalArticle

Abstract

Background and Purpose: Internal carotid artery (ICA) atheromatous disease is an important cause of ischemic stroke, and endarterectomy or stent placement is typically indicated for symptomatic patients with ≥70% stenosis. Our purpose was to compare contrast-enhanced MR angiography (CE-MRA) with unenhanced 2D time-of-flight MR angiography (2D TOF MRA) in detecting hemody - namically significant ICA stenosis, by using CT angiography (CTA) as the reference standard. MATERIALS AND METHODS: This was an institutional review board-approved retrospective study. We identified 177 consecutive patients (354 ICAs) who received correlative CE-MRA, 2D TOF MRA, and CTA. Two neuroradiologists blinded to the CTA data graded the degree of ICA stenosis according to a 5-point scale. Additionally, luminal signal-intensity characteristics including 1) signal intensity dropout, 2) distal-vessel narrowing, and 3) distal-vessel signal-intensity reduction were recorded. MRA results were correlated with those of CTA, and receiver-operating-characteristic (ROC) curves were constructed. Results: On CTA, there were 55 ICAs with and 299 without ≥70% stenosis. CE-MRA was 84% sensitive and 96% specific for detecting ≥70% stenosis; 2D TOF MRA was 80% sensitive and 95% specific. The area under the ROC curve was 0.97 for CE-MRA and 0.95 for 2D TOF MRA (P =.51, not significant). For both MRA studies, each of the luminal signal-intensity characteristics had high specificity (>98%) but poor-to-mild sensitivity (35%-66%) in detecting ≥70% stenosis. Conclusions: Although it is established that CE-MRA more accurately delineates neurovascular anatomy than does unenhanced 2D TOF MRA, the administration of gadolinium did not offer a significant advantage in distinguishing surgically treatable ICA stenosis. This conclusion may be important in patients with contraindications to gadolinium.

Original languageEnglish (US)
Pages (from-to)761-768
Number of pages8
JournalAmerican Journal of Neuroradiology
Volume30
Issue number4
DOIs
Publication statusPublished - Apr 2009
Externally publishedYes

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ASJC Scopus subject areas

  • Clinical Neurology
  • Radiology Nuclear Medicine and imaging

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