title: Reliability and accuracy of simple visual estimation in assessment of peripheral arterial stenosis.
abstract: OBJECTIVE
  To evaluate reliability, accuracy, and agreement of simple visual estimation (SVE) in determining the degree of peripheral arterial stenosis compared with calibrated measurements.
  
  
  METHODS
  In 2 sessions, 23 interventionists with a wide range of experience and subspecialty training reviewed 42 angiographic images of lower extremity and carotid arteries (21 iliofemoral arteries and 21 carotid arteries). An independent physician measured all lesions using manual calipers. Intrarater and interrater reliability were assessed by intraclass correlation. A ± 5% error was considered the threshold for accuracy, and weighted κ statistics were computed to assess agreement with respect to the degree of stenosis (< 50%, nonsignificant; 50%-80%, significant; > 80%, severe).
  
  
  RESULTS
  Intrarater reliability of SVE was 0.99, and interrater reliability was 0.83. Accuracy varied from 52.8% for images of severe stenosis to 26.5% and 18.1% for significant and nonsignificant stenosis, respectively (P < .001). Agreement between SVE and caliper with regard to degree of stenosis was good (weighted κ 0.56) overall with correct classification ranging from 92.6% for severe stenosis to 53.4% and 68.2% for significant and nonsignificant stenosis, respectively (P < .001). Misclassification of nonsignificant and significant stenosis was more frequent for carotid arteries than for lower extremities.
  
  
  CONCLUSIONS
  Despite high reliability, SVE of peripheral arterial stenosis has limited accuracy in determining the exact degree of stenosis. Although severe stenosis is readily identified by SVE, arterial stenosis of < 80% is frequently overestimated, especially for carotid arteries, and should be confirmed by caliper assessment.
authors.affiliation: Miami Cardiac and Vascular Institute, Miami, Florida; Department of Radiology, Division of Vascular and Interventional Radiology, Mayo Clinic, 200 1st Street SW, Rochester, MN 55905. Electronic address: Rajebi.reza@mayo.edu.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Rajebi
authors.affiliation: Miami Cardiac and Vascular Institute, Miami, Florida.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Benenati
authors.affiliation: Miami Cardiac and Vascular Institute, Miami, Florida; Department of Radiology, Division of Cardiovascular and Interventional Radiology, Medical University Vienna, Vienna, Austria.
authors.forename: Melanie B
authors.initials: MB
authors.lastname: Schernthaner
authors.affiliation: Center for Research and Grants, Baptist Health South Florida, Coral Gables, Florida.
authors.forename: Gail
authors.initials: G
authors.lastname: Walker
authors.affiliation: Miami Cardiac and Vascular Institute, Miami, Florida.
authors.forename: Ripal T
authors.initials: RT
authors.lastname: Gandhi
authors.affiliation: Miami Cardiac and Vascular Institute, Miami, Florida.
authors.forename: Constantino S
authors.initials: CS
authors.lastname: Pena
authors.affiliation: Miami Cardiac and Vascular Institute, Miami, Florida.
authors.forename: Barry T
authors.initials: BT
authors.lastname: Katzen
mesh_terms: D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D016893:Carotid Stenosis / Q000000981:diagnostic imaging*; D005263:Femoral Artery / Q000000981:diagnostic imaging*; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging*; D035002:Lower Extremity / Q000098:blood supply*; D015588:Observer Variation; D058729:Peripheral Arterial Disease / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D011379:Prognosis; D011859:Radiography; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index