A comparison of CH3-DTPA-GD (NMS60) and GD-DTPA for evaluation of acute myocardial ischemia

Our objective was to evaluate the use of a new medium weight MRI contrast agent, NMS60 (a synthetic oligomeric Gd-complex containing three Gd(3+) atoms, molecular weight 2158 Da) compared to gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) in a pig myocardial ischemia model. We used 13 male white hybrid pigs. Animals were scanned in the acute phase 2-3 h after the onset of myocardial ischemia. Scans were acquired on a 1.5T GE Signa with dynamic T1-weighted imaging during a bolus injection of 0.1 mmol(gd)/kg of either NMS60 or Gd-DTPA, 2D CINE at 5 min after injection, and T1-weighted spin-echo imaging up to 60 min. The postcontrast CINE scans showed improved contrast-to-noise ratio after NMS60 injection, compared to Gd-DTPA. There was significantly greater enhancement with NMS60 in both normal myocardium and in the ischemic lesion on T1-weighted spin-echo scans up to 60 min after injection. The dose ranging study shows a 24% greater enhancement with NMS60 compared to Gd-DTPA. This new medium weighted contrast agent offers improved enhancement for cardiac MRI, compared to Gd-DTPA, with similar washout kinetics and lower toxicity, and may prove useful for better detection of myocardial ischemia as well as delayed or hyperenhancement after reperfusion.