title: Distal lower extremity imaging: prospective comparison of 2-dimensional time of flight, 3-dimensional time-resolved contrast-enhanced magnetic resonance angiography, and 3-dimensional bolus chase contrast-enhanced magnetic resonance angiography.
abstract: OBJECTIVE
  To compare the 2-dimensional time of flight, the 3-dimensional time-resolved contrast-enhanced magnetic resonance (MR) angiography, and the 3-dimensional 3-station bolus chase contrast-enhanced MR angiography in assessing distal station atherosclerosis.
  
  
  METHODS
  Two-dimensional time of flight, 3-dimensional time-resolved contrast-enhanced MR angiography, and 3-dimensional bolus chase contrast-enhanced MR angiography were performed from the knees to the metatarsal heads of 40 patients. Blinded to the patients' identity, 2 readers independently reviewed the 3 sequences in random order; differences were resolved by consensus. Anterior tibial, peroneal, and posterior tibial arterial lengths to the talar dome were scored as follows: 1, greater than 50% of the length of a normal artery; 2, less than 50%; and 3, total occlusion. Stenoses were scored as follows: 1, less than 50%; and 2, greater than 50%. The pedal vessels (dorsalis pedis, posterior tibial, and plantar pedal arch arteries) were scored as follows: 1, less than 50% stenosis; and 2, greater than 50% stenosis. The reference standard was a combined interpretation of all 3 sequences by both readers in consensus.
  
  
  RESULTS
  For the 240 calf segments scored for length, concordance with reference assessment was poorer for the time of flight than for either the bolus chase or time-resolved angiography (P = 0.0021 and P = 0.0082, respectively), and the latter two were statistically indistinguishable. For stenosis grading of the 461 calf and pedal segments, the time-resolved and bolus chase methods were superior to the time of flight (P = <0.0001 and P = 0.0041, respectively), and the contrast-enhanced methods were statistically indistinguishable.
  
  
  CONCLUSIONS
  Both contrast-enhanced time-resolved and bolus chase MR angiography are superior to the time of flight in diagnosing distal station peripheral vascular disease.
authors.affiliation: Department of Radiology, Georgetown University Hospital, Washington, DC 20007, USA. wyh@gunet.georgetown.edu
authors.forename: Winnie Y
authors.initials: WY
authors.lastname: Hahn
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Hecht
authors.forename: Barak
authors.initials: B
authors.lastname: Friedman
authors.forename: James S
authors.initials: JS
authors.lastname: Babb
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Jacobowitz
authors.forename: Vivian S
authors.initials: VS
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007866:Leg / Q000098:blood supply*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016491:Peripheral Vascular Diseases / Q000175:diagnosis*; D011446:Prospective Studies; D016037:Single-Blind Method
chemical_list: D003287:Contrast Media