title: Performance of unenhanced respiratory-gated 3D SSFP MRA to depict hepatic and visceral artery anatomy and variants.
abstract: OBJECTIVE
  To prospectively evaluate the performance of unenhanced respiratory-gated magnetization-prepared 3D-SSFP inversion recovery MRA (unenhanced-MRA) to depict hepatic and visceral artery anatomy and variants in comparison to contrast-enhanced dynamic gradient-echo MRI (CE-MRI) and to digital subtraction angiography (DSA).
  
  
  METHODS
  Eighty-four patients (55.6±12.4 years) were imaged with CE-MRI (TR/TE 3.5/1.7ms, TI 1.7ms, flip-angle 15°) and unenhanced-MRA (TR/TE 4.4/2.2ms, TI 200ms, flip-angle 90°). Two independent readers assessed image quality of hepatic and visceral arteries on a 4-point-scale. Vessel contrast was measured by a third reader. In 28 patients arterial anatomy was compared to DSA.
  
  
  RESULTS
  Interobserver agreement regarding image quality was good for CE-MRI (κ=0.77) and excellent for unenhanced-MRA (κ=0.83). Unenhanced-MRA yielded diagnostic image quality in 71.6% of all vessels, whereas CE-MRI provided diagnostic image quality in 90.6% (p<0.001). Vessel-based image quality was significantly superior for all vessels at CE-MRI compared to unenhanced-MRA (p<0.01). Vessel contrast was similar among both sequences (p=0.15). Compared to DSA, CE-MRI and unenhanced-MRA yielded equal accuracy of 92.9-96.4% for depiction of hepatic and visceral artery variants (p=0.93).
  
  
  CONCLUSIONS
  Unenhanced-MRA provides diagnostic image quality in 72% of hepatic and visceral arteries with no significant difference in vessel contrast and similar accuracy to CE-MRI for depiction of hepatic and visceral anatomy.
authors.affiliation: Institute for Diagnostic and Interventional Radiology, University Hospital Zurich, Raemistrasse 100, CH-8091 Zurich, Switzerland. gilbert.puippe@usz.ch
authors.forename: Gilbert D
authors.initials: GD
authors.lastname: Puippe
authors.forename: Hatem
authors.initials: H
authors.lastname: Alkadhi
authors.forename: Roger
authors.initials: R
authors.lastname: Hunziker
authors.forename: Daniel
authors.initials: D
authors.lastname: Nanz
authors.forename: Thomas
authors.initials: T
authors.lastname: Pfammatter
authors.forename: Stephan
authors.initials: S
authors.lastname: Baumueller
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D063405:Anatomic Variation; D003287:Contrast Media; D005260:Female; D006499:Hepatic Artery / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques; D012680:Sensitivity and Specificity; D014781:Viscera / Q000098:blood supply* / Q000473:pathology*; D055815:Young Adult
chemical_list: D003287:Contrast Media