title: Diagnosis of carotid artery stenosis with oculopneumoplethysmography alone and in combination with MRA.
abstract: BACKGROUND
  The purpose of this study was to assess the accuracy of oculopneumoplethysmography (OPG) for the diagnosis of carotid artery stenosis both alone and in conjunction with carotid magnetic resonance angiography (MRA).
  
  
  METHODS
  This retrospective study reviewed patients who had undergone both OPG and digital subtraction angiography (DSA, 90 patients, 174 vessels) within two weeks to determine the accuracy of OPG with DSA as the reference standard for the detection of carotid artery stenosis. Three carotid artery stenosis thresholds (≥50%, ≥70%, ≥80%) were analyzed. The accuracy of the combination of OPG and MRA was analyzed in a subset of patients who underwent OPG and MRA and DSA (53 patients, 94 vessels).
  
  
  RESULTS
  The sensitivity and negative predictive value of OPG increased with higher-degree carotid artery stenoses, and for lesions ≥ 80%, these values were 85.3% and 94.2%, respectively. Specificity and positive predictive values were lower at all thresholds, and were 72.9% and 49.3%, respectively, at the ≥80% stenosis threshold. When OPG and MRA were concordant, the sensitivity and specificity for carotid artery stenoses ≥ 80% were 91.0% and 97.8%, respectively. OPG correctly identified 71.4% of false-positive and 80.0% of false-negative magnetic resonance angiographies for that degree of carotid artery stenosis.
  
  
  CONCLUSIONS
  OPG appears to be an accurate rule-out test for hemodynamically significant carotid artery stenosis. OPG augments the accuracy of MRA for detection of carotid artery disease.
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Elias
authors.forename: John T
authors.initials: JT
authors.lastname: Wald
authors.forename: David F
authors.initials: DF
authors.lastname: Kallmes
mesh_terms: D015901:Angiography, Digital Subtraction; D062186:Arterial Pressure; D016893:Carotid Stenosis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D018810:Magnetic Resonance Angiography; D009880:Ophthalmic Artery / Q000503:physiopathology*; D010991:Plethysmography / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index