title: Preoperative assessment of the carotid bifurcation. Can magnetic resonance angiography and duplex ultrasonography replace contrast arteriography?
abstract: OBJECTIVE
  Noninvasive studies are used with increasing frequency to assess the carotid bifurcation before endarterectomy. Therefore, assessment of their diagnostic accuracies is essential for appropriate patient management. We prospectively evaluate two noninvasive tests, magnetic resonance angiography (MRA) and duplex ultrasonography (DU), as potential replacements for contrast arteriography (CA).
  
  
  METHODS
  A blinded comparison of three-dimensional time-of-flight (TOF) MRA, two-dimensional TOF MRA, and DU in 176 arteries was performed. CA was used as the standard of comparison.
  
  
  RESULTS
  Three-dimensional TOF MRA had a sensitivity of 94%, a specificity of 85%, and an accuracy of 88% for the identification of 70% to 99% stenosis; two-dimensional TOF MRA had a sensitivity and specificity that were approximately 10% lower than those of three-dimensional TOF MRA. DU resulted in a sensitivity of 94%, a specificity of 83%, and an accuracy of 86%. Combining data from three-dimensional TOF MRA and DU, allowing for CA only for disparate results, yielded a sensitivity of 100%, a specificity of 91%, and an accuracy of 94% among concordant noninvasive tests, with CA required in 16% of arteries. MRA accurately differentiated 17 carotid occlusions from 16 high-grade (90% to 99%) stenoses, whereas with DU two patent arteries were identified as occluded and one occluded artery was identified as patent.
  
  
  CONCLUSIONS
  Three-dimensional TOF MRA is the most accurate noninvasive test. Combined use of MRA and DU results in a marked increase in accuracy to a level that obviates the need for CA in a majority of patients.
authors.affiliation: Department of Radiology, Beth Israel Hospital, Boston, MA 02215, USA.
authors.forename: M R
authors.initials: MR
authors.lastname: Patel
authors.forename: K M
authors.initials: KM
authors.lastname: Kuntz
authors.forename: R A
authors.initials: RA
authors.lastname: Klufas
authors.forename: D
authors.initials: D
authors.lastname: Kim
authors.forename: J
authors.initials: J
authors.lastname: Kramer
authors.forename: J F
authors.initials: JF
authors.lastname: Polak
authors.forename: J J
authors.initials: JJ
authors.lastname: Skillman
authors.forename: A D
authors.initials: AD
authors.lastname: Whittemore
authors.forename: R R
authors.initials: RR
authors.lastname: Edelman
authors.forename: K C
authors.initials: KC
authors.lastname: Kent
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D001161:Arteriosclerosis / Q000175:diagnosis / Q000000981:diagnostic imaging; D002342:Carotid Artery, External / Q000000981:diagnostic imaging / Q000473:pathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging; D003287:Contrast Media; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007089:Image Enhancement; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D016037:Single-Blind Method; D018616:Ultrasonography, Doppler, Duplex
chemical_list: D003287:Contrast Media