Coronary MR angiography using citrate‐coated very small superparamagnetic iron oxide particles as blood‐pool contrast agent: Initial experience in humans

Purpose: To evaluate very small superparamagnetic iron oxide particles (VSOP‐C184) as blood‐pool contrast agent for coronary MR angiography (CMRA) in humans. Materials and Methods: Six healthy volunteers and 14 patients with suspected coronary artery disease underwent CMRA after administration of VSOP‐C184 at the following doses: 20 μmol Fe/kg (4 patients), 40 μmol Fe/kg (5 patients), 45 μmol Fe/kg (6 healthy volunteers), and 60 μmol Fe/kg (5 patients). In healthy volunteers, contrast‐to‐noise ratio (CNR), signal‐to‐noise ratio (SNR), and vessel edge definition (VED) of contrast‐enhanced CMRA were compared with non–contrast‐enhanced CMRA. In patients, a per‐segment intention‐to‐diagnose evaluation of contrast‐enhanced CMRA for detection of significant coronary stenosis (≥50%) was performed. Results: Three healthy volunteers (45 μmol Fe/kg VSOP‐C184) and two patients (60 μmol Fe/kg VSOP‐C184) had adverse events of mild or moderate intensity. VSOP‐C184 significantly increased CNR (15.1 ± 4.6 versus 6.9 ± 1.9; P = 0.010), SNR (21.7 ± 5.3 versus 15.4 ± 1.6; P = 0.048), and VED (2.3 ± 0.6 versus 1.2 ± 0.2; P < 0.001) compared with non–contrast‐enhanced CMRA. In patients, contrast‐enhanced CMRA yielded sensitivity, specificity, and diagnostic accuracy for detection of significant coronary stenosis of 86.7%, 71.0%, 73.1%, respectively. Conclusion: CMRA using VSOP‐C184 was feasible and yielded moderate diagnostic accuracy for detection of significant coronary stenosis within this proof‐of‐concept setting. J. Magn. Reson. Imaging 2011;. © 2011 Wiley‐Liss, Inc.