title: Carotid duplex scanning: patterns of referral and outcome.
abstract: OBJECTIVE
  Review of the results of carotid Duplex scanning.
  
  
  METHODS
  Retrospective review of new referrals for carotid Duplex scanning to a regional vascular laboratory.
  
  
  METHODS
  1041 referrals made over an 18 month period.
  
  
  METHODS
  Referrals were reviewed for scan quality, diagnostic category and outcome of scanning.
  
  
  RESULTS
  The overall detection rate of ipsilateral stenoses > 70% and occlusions was 13.5%; the detection rate of surgically significant carotid lesions (70-99%) was only 8%. Analysis by diagnostic category revealed a significantly greater detection rate for carotid lesions > 70% in patients presenting with amaurosis fugax (24%) in comparison to those with TIAs (9.5%, p = 0.0005) or following a stroke (13%, p = 0.01). Patients referred with asymptomatic bruits or prior to cardiac surgery showed a positive scan rate of 30%. Sixty-seven carotid endarterectomies have resulted from scans performed in this period.
  
  
  CONCLUSIONS
  The overall rate of detection for surgically relevant lesions is low, but in comparison to a similar audit conducted in 1992, the absolute number of carotid lesions > 70% has risen by 60%. An 8% detection rate for surgically relevant lesions may be valuable in projecting the need for carotid endarterectomy arising from a given number of Duplex scans.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging; D001766:Blindness / Q000000981:diagnostic imaging; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000601:surgery; D016893:Carotid Stenosis / Q000000981:diagnostic imaging; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging; D002648:Child; D002675:Child, Preschool; D016894:Endarterectomy, Carotid; D005260:Female; D006801:Humans; D007089:Image Enhancement; D002546:Ischemic Attack, Transient / Q000000981:diagnostic imaging; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012017:Referral and Consultation; D012189:Retrospective Studies; D018616:Ultrasonography, Doppler, Duplex