title: Critical limb ischemia: hybrid MR angiography compared with DSA.
abstract: OBJECTIVE
  To compare a hybrid magnetic resonance (MR) angiography protocol with selective digital subtraction angiography (DSA) in patients with critical limb ischemia.
  
  
  METHODS
  The study was approved by the institutional review board, and written consent was obtained from all patients. Pretreatment DSA and hybrid MR angiography were performed in 19 consecutive patients (15 men, four women; mean age, 69.8 years; range, 44-86 years). Hybrid MR angiography included submillimeter dual-phase three-dimensional gadolinium-enhanced MR angiography in lower calf and foot, and four-station bolus-chase MR angiography in pelvis, thigh, and upper calf. Three readers identified the target lesion and inflow and outflow segments and determined treatment (bypass graft placement, percutaneous transluminal angioplasty, conservative management, amputation). Results of interobserver and intermethod comparisons were expressed as percentage of agreement and 95% confidence interval (CI).
  
  
  RESULTS
  On hybrid MR angiograms, no substantial venous overlay was present and image quality was excellent or adequate in 18 (95%) of 19 limbs. Readers 1, 2, and 3 selected the identical target lesion on the DSA image and the MR angiogram in 18, 17, and 18 of 18 comparable limbs, respectively. Mean percentage of agreement for readers 1 and 3 was 100% (95% CI: 81%, 100%) and for reader 2 was 94% (95% CI: 73%, 100%). Agreement of all three readers was superior with use of MR angiography for determination of inflow segments (13 [72%] of 18 limbs) and outflow segments (17 [94%] of 18 limbs), compared with agreement with use of DSA (13 [68%] of 19 inflow segments, 10 [53%] of 19 outflow segments). Agreement in therapy decisions was higher with DSA (15 [79%] of 19) than with MR angiography (11 [61%] of 18).
  
  
  CONCLUSIONS
  Preliminary data strongly support the combination of submillimeter dual-phase MR angiography in lower calf and foot with four-station bolus-chase MR angiography to extend the utility of MR angiography to patients with critical limb ischemia.
authors.affiliation: Institute for Clinical Radiology, Ludwig-Maximilians-University, Marchioninistrasse 15, 81377 Munich, Germany. oliver.meissner@med.uni-muenchen.de
authors.forename: Oliver A
authors.initials: OA
authors.lastname: Meissner
authors.forename: Johannes
authors.initials: J
authors.lastname: Rieger
authors.forename: Christof
authors.initials: C
authors.lastname: Weber
authors.forename: Uwe
authors.initials: U
authors.lastname: Siebert
authors.forename: Bernd
authors.initials: B
authors.lastname: Steckmeier
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Stefan O
authors.initials: SO
authors.lastname: Schoenberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D016638:Critical Illness; D005260:Female; D006801:Humans; D007511:Ischemia / Q000000981:diagnostic imaging*; D007866:Leg / Q000098:blood supply*; D018810:Magnetic Resonance Angiography / Q000379:methods; D008297:Male; D008875:Middle Aged