Ulrike I. Attenberger MD, Presenter: Nothing to Disclose

John Nicholas Morelli MD, Abstract Co-Author: Nothing to Disclose

Val Murray Runge MD, Abstract Co-Author: Research grant, Bracco Group Research grant, Bayer AG

Fei Ai MD, Abstract Co-Author: Nothing to Disclose

Wei Zhang, Abstract Co-Author: Nothing to Disclose

Matthew Miller, Abstract Co-Author: Nothing to Disclose

To establish the minimum dose required for detection of renal artery stenosis using high spatial resolution, contrast enhanced, time resolved Magnetic Resonance Angiography (MRA) at 3 T.

Bilateral moderate to high-grade renal artery stenoses were surgically created and subsequently imaged both on MR at 3 T (Siemens Medical Solutions, Verio) and by DSA (Philips Medical Systems, Allura 3D FD20) in 7 swine to date, in this ongoing IACUC approved protocol. 5 additional swine were employed for initial protocol optimization. Gadobutrol (Gadovist, Bayer Schering Pharma) was injected intravenously at doses of 0.5, 1, 2, and 4 ml at a rate of 2 ml/sec for time resolved MRA (1.5 x 1.5 mm2 in-plane spatial resolution). High-resolution, fast spoiled gradient-refocused echo, contrast enhanced MRA and DSA were acquired for additional stenosis quantification. Region of interest statistical analysis was performed together with a blinded read.

In a preliminary read (n=6), 1 ml in all instances was the lowest dose that allowed visualization of each renal artery stenosis, 0.5 ml was non-diagnostic in all cases, with 2 and 4 ml providing equivalent image quality. CNR for the aorta at the level of the renal arteries was 17±9 (0.5 ml), 65±34 (1 ml), 86±37 (2 ml) and 92±20 (4 ml). No statistically significant difference was noted for CNR (for the aorta or renal arteries) between the 2 and 4 ml doses. CNR in the aorta was statistically significantly different when comparing 0.5 vs 1 ml (p<.03), and 1 vs 2 ml (p=.05). For the renal arteries there was no statistically significant difference for 1 vs 2 ml for the left renal artery, and marginally for the right. The degree of stenosis as quantitated by DSA ranged from 44 to 82% (n=12).

Intraindividual MRA evaluation, using advanced view sharing MR technique, demonstrates that renal artery stenosis can be assessed with very low doses of a high concentration, high relaxivity gadolinium chelate formulation, limiting patient exposure to gadolinium based contrast agents and thus NSF.

At 3 T renal artery stenosis can be detected with a dose as low as 1 ml (0.02 mmoL/kg) using a 1 M macrocyclic gadolinium chelate.

Attenberger, U, Morelli, J, Runge, V, Ai, F, Zhang, W, Miller, M, High Spatial Resolution Time Resolved MR Angiography of Renal Artery Stenosis Using Gadobutrol with DSA Correlation.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9013274.html