title: Evaluating peripheral arterial disease with unenhanced quiescent-interval single-shot MR angiography at 3 T.
abstract: OBJECTIVE
  The objective of our study was to assess the diagnostic performance of quiescent-interval single-shot (QISS) MR angiography (MRA) at 3 T for the evaluation of chronic lower limb ischemia.
  
  
  METHODS
  For this prospective study, 25 patients referred for lower extremity angiography for suspected or known chronic peripheral arterial disease were imaged on a 3-T system using QISS MRA. Contrast-enhanced MRA of the lower extremities was acquired at 3 T for each patient at the time of the initial visit and served as the noninvasive reference standard. Two blinded reviewers separately graded the degree of arterial stenosis. The sensitivity and specificity of QISS MRA for the determination of significant (≥ 50%) stenosis were calculated against contrast-enhanced MRA. Subsequent selective digital subtraction angiography (DSA) was performed and reviewed in nine patients.
  
  
  RESULTS
  QISS MRA exhibited diagnostic performance nearly equivalent to that of contrast-enhanced MRA and also showed strong correlation with findings on DSA. Segment-based analysis revealed that, for the two reviewers, QISS MRA had sensitivities of 95.9% (142 of 148 segments) and 93.5% (145 of 155 segments) and specificities of 98.5% (595 of 604 segments) and 97.0% (578 of 596 segments) on comparison with contrast-enhanced MRA.
  
  
  CONCLUSIONS
  QISS MRA maintains high diagnostic performance at 3 T despite the challenges inherent to image acquisition at higher field strengths.
authors.affiliation: 1 Department of Radiology, Northwestern Memorial Hospital, 737 N Michigan Ave, Ste 1600, Chicago, IL 60611.
authors.forename: Parag
authors.initials: P
authors.lastname: Amin
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Collins
authors.forename: Ioannis
authors.initials: I
authors.lastname: Koktzoglou
authors.forename: Christopher
authors.initials: C
authors.lastname: Molvar
authors.forename: Michael
authors.initials: M
authors.lastname: Markl
authors.forename: Robert R
authors.initials: RR
authors.lastname: Edelman
authors.forename: James C
authors.initials: JC
authors.lastname: Carr
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D021621:Imaging, Three-Dimensional; D035002:Lower Extremity / Q000098:blood supply; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D058729:Peripheral Arterial Disease / Q000175:diagnosis* / Q000473:pathology; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D005682:Gadolinium; C109932:gadofosveset trisodium