title: Decreased venous contamination on 3D gadolinium-enhanced bolus chase peripheral mr angiography using thigh compression.
abstract: OBJECTIVE
  We evaluated the potential for improving bolus chase peripheral MR angiography in patients with fast arterial flow using thigh compression to prevent venous contamination.
  
  
  METHODS
  We performed bolus chase peripheral MR angiography in 32 consecutive patients in whom the travel time for a contrast agent to reach the popliteal artery trifurcation was less than 25 sec. Thigh compression was applied by a tourniquet (n = 13) or blood pressure cuff inflated to 60 mm Hg (n = 19). We compared the results with those of 36 consecutive patients who underwent angiography without thigh compression. The effect of thigh compression on arterial flow and tissue enhancement was assessed in patients with symmetric travel time in both legs by applying compression to one leg during the time-resolved 2D-projection MR angiography with 6 mL of gadolinium. On 3D bolus chase MR angiography, thigh compression was applied bilaterally. Venous contamination on the 3D images of the calf was graded as 0, none; 1, trace; 2, mild; 3, moderate; and 4, severe. Signal-to-noise ratio was measured in the popliteal artery.
  
  
  RESULTS
  Thigh compression slowed the arterial travel time by a mean +/- SD of 4.7 +/- 2 sec (p < 0.001) with a blood pressure cuff and 3.1 +/- 1 sec (p < 0.001) with a tourniquet. Blood pressure cuffs reduced the score of venous contamination on the calf station from 1.9 to 0.4 (p < 0.05) for intermediate flow (contrast travel time, 20-25 sec) and from 2.5 to 0.9 (p < 0.05) for fast flow (< 20 sec). Thigh compression increased the popliteal artery signal-to-noise ratio (81 vs 52, p < 0.001).
  
  
  CONCLUSIONS
  Thigh compression with blood pressure cuffs inflated to 60 mm Hg slows down arterial flow, increases arterial signal-to-noise ratio, and reduces venous contamination on 3D gadolinium-enhanced bolus chase peripheral MR angiography.
authors.affiliation: Cornell MRI, Weill Medical College of Cornell University, 416 E 55th St., New York, NY 10022, USA. hoz2005@med.cornell.edu <hoz2005@med.cornell.edu>
authors.forename: Hong Lei
authors.initials: HL
authors.lastname: Zhang
authors.forename: Bernard Y
authors.initials: BY
authors.lastname: Ho
authors.forename: Minh
authors.initials: M
authors.lastname: Chao
authors.forename: K Craig
authors.initials: KC
authors.lastname: Kent
authors.forename: Harry L
authors.initials: HL
authors.lastname: Bush
authors.forename: Peter L
authors.initials: PL
authors.lastname: Faries
authors.forename: Alan I
authors.initials: AI
authors.lastname: Benvenisty
authors.forename: Martin R
authors.initials: MR
authors.lastname: Prince
mesh_terms: D000368:Aged; D001458:Bandages; D001783:Blood Flow Velocity; D003287:Contrast Media / Q000493:pharmacokinetics*; D005260:Female; D019786:Gadolinium DTPA / Q000493:pharmacokinetics*; D006801:Humans; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D011312:Pressure; D013848:Thigh / Q000098:blood supply*
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA