Magnus Karlsson

MR coronary angiography in pigs with intraarterial injections of a hyperpolarized (13)C substance.

A new diagnostic application of a water‐soluble contrast medium (CM) based on the hyperpolarization of a 13C substance is introduced. The degree of polarization achieved is >30%, which is about a factor of 105 higher than the thermal equilibrium polarization level at 1.5 T. Imaging of hyperpolarized (HP) CM during a cardiac interventional MRI procedure was studied. Catheters were positioned in the left and right coronary arteries of pigs. A coil tuned to 13C was used for nonproton imaging. The HP‐13C CM (∼5 ml, 0.5 M, ∼30% polarization) was injected during projection imaging using a fully balanced steady‐state free precession (SSFP) pulse sequence with and without cardiac gating. The contrast agent‐filled catheter was clearly visible during the procedure. The coronary arteries were well depicted and the signal‐to‐noise ratios (SNRs) were in the range of 10–40. The use of HP‐13C CM may provide a new diagnostic procedure for interventional MRI. Magn Reson Med, 2006.