title: MR angiography of collateral arteries in a hind limb ischemia model: comparison between blood pool agent Gadomer and small contrast agent Gd-DTPA.
abstract: The objective of this study was to compare the blood pool agent Gadomer with a small contrast agent for the visualization of ultra-small, collateral arteries (diameter<1 mm) with high resolution steady-state MR angiography (SS-MRA) in a rabbit hind limb ischemia model. Ten rabbits underwent unilateral femoral artery ligation. On days 14 and 21, high resolution SS-MRA (voxel size 0.49×0.49×0.50 mm(3)) was performed on a 3 Tesla clinical system after administration of either Gadomer (dose: 0.10 mmol/kg) or a small contrast agent (gadopentetate dimeglumine (Gd-DTPA), dose: 0.20 mmol/kg). All animals received both contrast agents on separate days. Selective intra-arterial x-ray angiograms (XRAs) were obtained in the ligated limb as a reference. The number of collaterals was counted by two independent observers. Image quality was evaluated with the contrast-to-noise ratio (CNR) in the femoral artery and collateral arteries. CNR for Gadomer was higher in both the femoral artery (Gadomer: 73±5 (mean ± SE); Gd-DTPA: 40±3; p<0.01) and collateral arteries (Gadomer: 18±4; Gd-DTPA: 9±1; p = 0.04). Neither day of acquisition nor contrast agent used influenced the number of identified collateral arteries (p = 0.30 and p = 0.14, respectively). An average of 4.5±1.0 (day 14, mean ± SD) and 5.3±1.2 (day 21) collaterals was found, which was comparable to XRA (5.6±1.7, averaged over days 14 and 21; p>0.10). Inter-observer variation was 24% and 18% for Gadomer and Gd-DTPA, respectively. In conclusion, blood pool agent Gadomer improved vessel conspicuity compared to Gd-DTPA. Steady-state MRA can be considered as an excellent non-invasive alternative to intra-arterial XRA for the visualization of ultra-small collateral arteries.
authors.affiliation: Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands.
authors.forename: Karolien
authors.initials: K
authors.lastname: Jaspers
authors.forename: Bas
authors.initials: B
authors.lastname: Versluis
authors.forename: Tim
authors.initials: T
authors.lastname: Leiner
authors.forename: Petra
authors.initials: P
authors.lastname: Dijkstra
authors.forename: Marlies
authors.initials: M
authors.lastname: Oostendorp
authors.forename: Jolanda M
authors.initials: JM
authors.lastname: van Golde
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Post
authors.forename: Walter H
authors.initials: WH
authors.lastname: Backes
mesh_terms: D000818:Animals; D001158:Arteries / Q000473:pathology*; D003097:Collateral Circulation; D003287:Contrast Media / Q000737:chemistry* / Q000592:standards; D004195:Disease Models, Animal; D005682:Gadolinium; D019786:Gadolinium DTPA; D006614:Hindlimb / Q000098:blood supply* / Q000473:pathology; D007511:Ischemia / Q000473:pathology*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D011817:Rabbits
chemical_list: D003287:Contrast Media; D005682:Gadolinium; D019786:Gadolinium DTPA