title: Distinguishing carotid artery pseudo-occlusion with color-flow Doppler.
abstract: OBJECTIVE
  This study was undertaken to determine the impact of color-flow Doppler on the accuracy of noninvasive carotid imaging for distinguishing an internal carotid artery pseudo-occlusion (string sign) from a complete occlusion.
  
  
  METHODS
  From January 1985 to January 1994, review of noninvasive vascular studies, arteriograms, and operative reports of 26 consecutive patients undergoing 27 carotid endarterectomies for carotid pseudo-occlusion was performed. Further review was conducted of all patients identified with carotid occlusion by noninvasive testing who underwent confirmatory arteriography during the same interval.
  
  
  RESULTS
  Conventional gray-scale duplex scanning (January 1985 to December 1989) correctly identified 3 of 11 (27%) pseudo-occluded internal carotid arteries compared with 15 of 16 (94%) internal carotid artery pseudo-occlusions correctly identified by color-flow Doppler (January 1990 to June 1994) (P < .01). Similarly, carotid occlusion was more accurately identified by color-flow Doppler (33 of 33, 100%) compared with gray-scale duplex scanning (19 of 27, 90%) (P < .01).
  
  
  CONCLUSIONS
  The addition of color-flow Doppler to the duplex evaluation of the extracranial carotid circulation improves the accuracy of distinguishing carotid pseudo-occlusion from the occluded internal carotid artery and may obviate the need for arteriography to identify patients with this critical level of carotid stenosis.
authors.affiliation: Section of Vascular Surgery, University of Arizona Health Sciences Center, Tucson 85724.
authors.forename: S S
authors.initials: SS
authors.lastname: Berman
authors.forename: J J
authors.initials: JJ
authors.lastname: Devine
authors.forename: L S
authors.initials: LS
authors.lastname: Erdoes
authors.forename: G C
authors.initials: GC
authors.lastname: Hunter
mesh_terms: D000208:Acute Disease; D015901:Angiography, Digital Subtraction; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D002341:Carotid Artery Thrombosis / Q000000981:diagnostic imaging / Q000473:pathology; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000473:pathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000473:pathology; D016893:Carotid Stenosis / Q000000981:diagnostic imaging / Q000473:pathology; D002561:Cerebrovascular Disorders / Q000601:surgery; D003937:Diagnosis, Differential; D016894:Endarterectomy, Carotid; D006801:Humans; D002546:Ischemic Attack, Transient / Q000601:surgery; D012008:Recurrence; D012039:Regional Blood Flow / Q000502:physiology; D012189:Retrospective Studies; D018615:Ultrasonography, Doppler, Color; D014654:Vascular Patency; D014655:Vascular Resistance / Q000502:physiology