Reperfused myocardial infarction as seen with use of necrosis-specific versus standard extracellular MR contrast media in rats.

Abstract

PURPOSE:

To measure the difference in size of reperfused myocardial infarction with necrosis-specific (bis-gadolinium-mesoporphyrin [hereafter, mesoporphyrin]) and standard extracellular (gadopentetate dimeglumine) magnetic resonance (MR) contrast media.

MATERIALS AND METHODS:

Echo-planar (for T1 measurement) and spin-echo (for infarction size) MR imaging were conducted in 32 rats subjected to reperfused reversible (n = 16) and irreversible (n = 16) myocardial injuries. All animals received gadopentetate dimeglumine 1 hour after reperfusion and underwent imaging. Sixteen rats received mesoporphyrin at 2 hours, the other 16 rats received gadopentetate dimeglumine at 24 hours, and all animals underwent imaging at 24 hours.

RESULTS:

Mesoporphyrin produced prolonged (22 hours) reduction in T1 in irreversibly, but not in reversibly, injured myocardium. The size of the mesoporphyrin-enhanced region (37% +/- 4 [SEM] of left ventricular surface area) closely correlated with the true infarction size as measured by means of histomorphometry (36% +/- 3, r = 0.90). The size of the gadolinium-enhanced region overestimated (48% +/- 2 and 43% +/- 1 at 1 and 24 hours of reperfusion, respectively) the size of true infarction (36% +/- 3, P < .05, r = 0.02), but it was close to the size of the area at risk (r = 0.93).

CONCLUSION:

The sizes of hyperenhanced regions displayed by using mesoporphyrin and gadopentetate dimeglumine differed from each other. The difference in size of the hyperenhanced region demarcated by mesoporphyrin and gadopentetate dimeglumine may provide an estimation of potentially salvageable myocardium.

• Authors: M Saeed, J Bremerich, M F Wendland, R Wyttenbach, H J Weinmann, C B Higgins
• Journal: Radiology (Radiology) Vol. 213 Issue 1 Pg. 247-57 (Oct 1999) ISSN: 0033-8419 [Print] United States
• PMID: 10540668 (Publication Type: Comparative Study, Journal Article)

Chemical References

• Contrast Media
• Mesoporphyrins
• mesoporphyrin IX
• Gadolinium
• Gadolinium DTPA

Topics

• Animals
• Contrast Media
• Echo-Planar Imaging
• Female
• Gadolinium
• Gadolinium DTPA
• Magnetic Resonance Imaging
• Mesoporphyrins
• Myocardial Infarction (diagnosis, pathology)
• Myocardial Reperfusion
• Myocardium (pathology)
• Necrosis
• Rats
• Rats, Sprague-Dawley