title: Diagnostic performance of computed tomography angiography in peripheral arterial disease: a systematic review and meta-analysis.
abstract: BACKGROUND
  Computed tomography angiography (CTA) is an increasingly attractive imaging modality for assessing lower extremity peripheral arterial disease (PAD).
  
  
  OBJECTIVE
  To determine the accuracy of CTA compared with intra-arterial digital subtraction angiography (DSA) in differentiating extent of disease in patients with PAD.
  
  
  METHODS
  Search of MEDLINE (January 1966-August 2008), EMBASE (January 1980-August 2008), and the Database of Abstracts of Reviews of Effectiveness for studies comparing CTA with intra-arterial DSA for PAD. Eligible studies compared multidetector CTA with intra-arterial DSA, included at least 10 patients with intermittent claudication or critical limb ischemia, aimed to detect more than 50% stenosis or arterial occlusion, and presented either 2 x 2 or 3 x 3 contingency tables (< or = 50% stenosis vs > 50% stenosis or occlusion), or provided data allowing their construction.
  
  
  METHODS
  Two reviewers screened potential studies for inclusion and independently extracted study data. Methodological quality was assessed by using the QUADAS instrument.
  
  
  RESULTS
  Of 909 studies identified, 20 (2.2%) met the inclusion criteria. These 20 studies had a median sample size of 33 (range, 16-279) and included 957 patients, predominantly with intermittent claudication (68%). Methodological quality was moderate. Overall, the sensitivity of CTA for detecting more than 50% stenosis or occlusion was 95% (95% confidence interval [CI], 92%-97%) and specificity was 96% (95% CI, 93%-97%). Computed tomography angiography correctly identified occlusions in 94% of segments, the presence of more than 50% stenosis in 87% of segments, and absence of significant stenosis in 96% of segments. Overstaging occurred in 8% of segments and understaging in 15%.
  
  
  CONCLUSIONS
  Computed tomography angiography is an accurate modality to assess presence and extent of PAD in patients with intermittent claudication; however, methodological weaknesses of examined studies prevent definitive conclusions from these data.
authors.affiliation: Department of Radiology, Academic Medical Center, PO Box 22660, 1100 DD Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. r.met@amc.uva.nl
authors.forename: Rosemarie
authors.initials: R
authors.lastname: Met
authors.forename: Shandra
authors.initials: S
authors.lastname: Bipat
authors.forename: Dink A
authors.initials: DA
authors.lastname: Legemate
authors.forename: Jim A
authors.initials: JA
authors.lastname: Reekers
authors.forename: Mark J W
authors.initials: MJ
authors.lastname: Koelemay
mesh_terms: D015901:Angiography, Digital Subtraction / Q000295:instrumentation; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging*; D015986:Confounding Factors, Epidemiologic; D003937:Diagnosis, Differential; D006801:Humans; D007511:Ischemia / Q000209:etiology; D007866:Leg / Q000098:blood supply; D016491:Peripheral Vascular Diseases / Q000000981:diagnostic imaging*; D011237:Predictive Value of Tests; D017594:Publication Bias; D012107:Research Design; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed