Noninvasive measurements of infarct size after thrombolysis with a necrosis-avid MRI contrast agent.

Abstract

BACKGROUND:

Gadophrin-2 is a new MRI contrast agent with high affinity for necrotic myocardium. The aim of the study was to evaluate whether noninvasive measurements of infarct size after thrombolysis are possible with gadophrin-2-enhanced MRI.

METHODS AND RESULTS:

Coronary artery thrombosis was induced in 3 groups of dogs by the copper-coil technique. Thrombolytic therapy together with aspirin and heparin was initiated after 90 minutes of occlusion. One day (group A), 2 days (group B), or 6 days (group C) after infarction, gadophrin-2 was injected intravenously (50 micromol. kg-1). In vivo T1-weighted segmented turbo-FLASH, in vivo T2-weighted segmented half-Fourier turbo spin echo (HASTE), and T1- and T2-weighted spin-echo MRI of the excised heart were performed 24 hours after gadophrin-2 injection. Regions of strong enhancement were observed on T1-weighted images. Planimetry of short-axis MR images and of corresponding triphenyltetrazolium chloride (TTC)-stained left ventricular (LV) slices showed a close correlation between the enhanced areas and TTC-negative areas for both in vivo (r2=0.98, P<0.0001; mean difference, 0.9+/-2.0% [SD] of the LV volume [LVV]) and postmortem (r2=0.99, P<0.0001; mean difference, 0.9+/-1.4% of LVV) measurements. T2-weighted images overestimated the infarct size by 8.1+/-5.4% of LVV. The mean infarct size was 10.8+/-11.6% of LVV (group A), 22.4+/-11.7% (group B), and 5.1+/-9.3% (group C).

CONCLUSIONS:

In this animal model, in vivo gadophrin-2-enhanced MRI could precisely determine infarct size after thrombolytic therapy. This technique may be very useful for the noninvasive evaluation of infarct size after reperfusion for AMI.

• Authors: S V Pislaru, Y Ni, C Pislaru, H Bosmans, Y Miao, J Bogaert, S Dymarkowski, W Semmler, G Marchal, F J Van de Werf
• Journal: Circulation (Circulation) Vol. 99 Issue 5 Pg. 690-6 (Feb 09 1999) ISSN: 0009-7322 [Print] United States
• PMID: 9950668 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Contrast Media
• Heparin
• Aspirin

Topics

• Animals
• Aspirin (therapeutic use)
• Contrast Media
• Coronary Thrombosis (drug therapy, pathology)
• Dogs
• Drug Therapy, Combination
• Heparin (therapeutic use)
• Image Enhancement
• Magnetic Resonance Imaging
• Myocardial Infarction (diagnosis)
• Necrosis
• Thrombolytic Therapy