Gadolinium-free T1 contrast agents for MRI: Tunable pharmacokinetics of a new class of manganese porphyrins
Article first published online: 8 NOV 2013
Copyright © 2013 Wiley Periodicals, Inc.
Journal of Magnetic Resonance Imaging
How to Cite
Cheng, H.-L. M., Haedicke, I. E., Cheng, W., Tchouala Nofiele, J. and Zhang, X.-a. (2013), Gadolinium-free T1 contrast agents for MRI: Tunable pharmacokinetics of a new class of manganese porphyrins. J. Magn. Reson. Imaging. doi: 10.1002/jmri.24483
- Article first published online: 8 NOV 2013
- Manuscript Accepted: 4 OCT 2013
- Manuscript Received: 3 SEP 2013
- Natural Sciences and Engineering Research Council of Canada (NSERC) . Grant Numbers: 355795 (to H.L.C.) , 489075 (to X.-a.Z.)
- Garron Family Cancer Centre Grant through the SickKids Foundation (to H.L.C.)
- positive contrast MRI contrast agents;
- dynamic contrast-enhanced (DCE) MRI;
- permeability imaging;
- cardiovascular imaging;
- liver imaging
To evaluate a new class of manganese porphyrins with tunable pharmacokinetics as potential gadolinium (Gd)-free T1 agents for contrast-enhanced magnetic resonance imaging (MRI).
Materials and Methods
Two new contrast agents, MnTCP and MnP2, were evaluated in four female rats. MRI was performed daily up to 3 days postinjection (0.05 mmol/kg) on a 3 T clinical scanner. T1 relaxation times and dynamic contrast-enhanced MRI were performed to assess contrast enhancement and clearance in blood, heart, liver, kidney, and muscle.
Relative T1 decreases were similar for MnTCP and Gd-DTPA in all tissues but were significantly larger (P < 0.05) for MnP2 in blood, heart, kidney, and liver (2–6-fold larger). Clearance of MnTCP was similar to Gd-DTPA, with T1 returning to baseline by 40 minutes and complete elimination in 1 day. MnP2 was cleared from blood after 2 days and sustained a lowered T1 in other tissues for at least 1 hour (P < 0.05). The maximum enhancement, slope, and time-to-peak were similar between contrast agents. Only the parameter AUC60 differed, with MnP2 yielding the largest AUC60 values primarily through longer retention in tissue.
MnTCP and MnP2 offer distinct applications as Gd-free T1 contrast agents. MnTCP behaves like a Gd-DTPA analog, while MnP2 provides significantly greater and longer positive signal enhancement.J. Magn. Reson. Imaging 2013. © 2013 Wiley Periodicals, Inc.