Slow clearance gadolinium‐based extracellular and intravascular contrast media for three‐dimensional MR angiography

The objective of this study was to assess two new slow‐clearance contrast media with extracellular and intravascular distribution for magnetic resonance angiography (MRA). Extracellular Gd‐DTPA‐BC 2 glucA and intravascular Gd(DO3A) 3 ‐lys 16 were developed within the European Biomed2 MACE Program and compared with two reference compounds, intravascular CMD‐A2‐Gd‐DOTA and extracellular GdDOTA, in 12 rats. Pre‐ and post‐contrast three‐dimensional MR (TR/TE = 5 msec/2.2 msec; isotropic voxel size 0.86 mm 3 ) was acquired for 2 hours. Signal‐to‐noise enhancement (ΔSNR) was calculated. Two minutes after injection, all contrast media provided strong vascular signal enhancement. The ΔSNR for Gd‐DTPA‐BC 2 glucA, Gd(DO3A) 3 ‐lys 16 , CMD‐A2‐Gd‐DOTA, and GdDOTA were 13.0 ± 1.8, 25.0 ± 3.2, 25.0 ± 4.0, and 18.0 ± 3.4, respectively. Gd‐DTPA‐BC 2 glucA, Gd(DO3A) 3 ‐lys 16 , and CMD‐A2‐Gd‐DOTA cleared slowly from the circulation, whereas GdDOTA cleared rapidly. Vascular ΔSNR at 2 hours were 2.9 ± 0.6, 25.0 ± 3.2, 25.0 ± 4.0, and 0.4 ± 1.0. Gd(DO3A) 3 ‐lys 16 provided strong vascular and minor background enhancement, and thus may be useful for MRA or perfusion imaging. Gd‐DTPA‐BC 2 glucA produces persistent enhancement of extracellular water, and thus may allow quantification of extracellular distribution volume and assessment of myocardial viability. J. Magn. Reson. Imaging 2001;13:588–593. © 2001 Wiley‐Liss, Inc.