Time-of-flight MR angiography with Gd-DTPA hexamethylene diamine co-polymer blood pool contrast agent: Comparison of enhanced MRA and conventional angiography for arterial stenosis induced in rabbits

Vascular stenoses were Induced in the external iliac arteries of New Zealan d white rabbits by a combination of hypercholesterolemic diet and repeat ba lloon injury. Two-dimensional (2D) and three-dimensional (3D) time-of-fligh t (TOP) magnetic resonance angiography (MRA) was performed with a specifica lly designed phased array coil in a 1.5 T system. Enhancement with gadolini um-diethylene triamine pentaacetic acid (Gd-DTPA) hexamethylene diamine co- polymer (Nycomed: NC 22181), a blood pool MR contrast agent, was measured a fter contrast administration and compared with pre-contrast images at the s ame levels. Vessel diameter measurements were obtained at multiple levels a nd compared with comparable levels on conventional angiograms of the same a nimals. Stable enhancement, averaging 227% above baseline, was observed wit h the 3D TOP MRA over the 40 minutes of this study. Enhancement was not obs erved with the 2D TOF technique. Measurement of the smallest vessels in thi s study with 3D TOF MRA was slightly improved following contrast enhancemen t, although both pre- and post-contrast diameter measurements tended to und erestimate the assumed true vessel diameter. Thus, Gd-DTPA hexamethylene di amine co-polymer (Nycomed: NC 22181), a blood pool MR contrast agent, produ ces significant, stable enhancement with the 3D TOF technique and may impro ve MRA measurement of small vessels. J. Magn. Reson. Imaging 2000; 11:638-6 46. (C) 2000 Wiley-Liss, Inc.