title: Ankle brachial index <0.9 underestimates the prevalence of peripheral artery occlusive disease assessed with whole-body magnetic resonance angiography in the elderly.
abstract: BACKGROUND
  Whole-body magnetic resonance angiography (WBMRA) permits noninvasive vascular assessment, which can be utilized in epidemiological studies.
  
  
  OBJECTIVE
  To assess the relation between a low ankle brachial index (ABI) and high-grade stenoses in the pelvic and leg arteries in the elderly.
  
  
  METHODS
  WBMRA was performed in a population sample of 306 subjects aged 70 years. The arteries below the aortic bifurcation were graded after the most severe stenosis according to one of three grades: 0-49% stenosis, 50-99% stenosis, or occlusion. ABI was calculated for each side.
  
  
  RESULTS
  There were assessable WBMRA and ABI examinations in 268 (right side), 265 (left side), and 258 cases (both sides). At least one > or =50% stenosis was found in 19% (right side), 23% (left side), and 28% (on at least one side) of the cases. The corresponding prevalences for ABI <0.9 were 4.5%, 4.2%, and 6.6%. An ABI cut-off value of 0.9 resulted in a sensitivity, specificity, and positive and negative predictive value of 20%, 99%, 83%, and 84% on the right side, and 15%, 99%, 82%, and 80% on the left side, respectively, for the presence of a > or =50% stenosis in the pelvic or leg arteries.
  
  
  CONCLUSIONS
  An ABI <0.9 underestimates the prevalence of peripheral arterial occlusive disease in the general elderly population.
authors.affiliation: Department of Radiology and Department of Medical Sciences, Uppsala University Hospital, Uppsala, Sweden. johan.wikstrom@radiol.uu.se
authors.forename: J
authors.initials: J
authors.lastname: Wikström
authors.forename: T
authors.initials: T
authors.lastname: Hansen
authors.forename: L
authors.initials: L
authors.lastname: Johansson
authors.forename: L
authors.initials: L
authors.lastname: Lind
authors.forename: H
authors.initials: H
authors.lastname: Ahlström
mesh_terms: D000368:Aged; D000842:Ankle / Q000098:blood supply*; D001157:Arterial Occlusive Diseases / Q000175:diagnosis* / Q000453:epidemiology; D001916:Brachial Artery / Q000503:physiopathology*; D015331:Cohort Studies; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007866:Leg / Q000098:blood supply; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D010388:Pelvis / Q000098:blood supply; D016491:Peripheral Vascular Diseases / Q000175:diagnosis* / Q000453:epidemiology; D011237:Predictive Value of Tests; D015995:Prevalence; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D051598:Whole Body Imaging / Q000379:methods*
chemical_list: D003287:Contrast Media; C064925:gadodiamide; D019786:Gadolinium DTPA