Myocardial magnetic resonance imaging contrast agent concentrations after reversible and irreversible ischemic injury

Circulation. 2002 Jan 15;105(2):224-9. doi: 10.1161/hc0202.102016.


Background: Discrepant reports have been published recently regarding the relationship of contrast-enhanced magnetic resonance image intensities to reversible and irreversible ischemic injury. Unlike image intensities, contrast agent concentrations provide data independent of the MRI technique. We used electron probe x-ray microanalysis (EPXMA) to simultaneously examine concentrations of Gd, Na, P, S, Cl, K, and Ca over a range of myocardial injuries. Methods and Results- Reversible and irreversible injury were studied in 38 rabbits divided into 4 groups defined by occlusion and reperfusion time, as well as time the animals were euthanized. Gd-DTPA was administered, and the hearts were excised and rapidly frozen, cryosectioned, freeze-dried, and examined by EPXMA in up to 3 regions: remote, infarcted, and at risk but not infarcted. Infarcted regions were defined by anti-myoglobin antibody or triphenyltetrazolium chloride staining. Regions at risk were defined by fluorescent microparticles administered during occlusion. Compared with remote regions, in acutely infarcted regions, Gd was increased (235+/-24%, P<0.005) in the same 50 x 100-microm areas in which Na was increased (154+/-5%, P<0.001) and K was decreased (52+/-8%, P<0.001). Similarly, in chronically infarcted regions, Gd was increased (472+/-78%, P<0.001) in areas in which Na was increased (332+/-28%, P<0.001) and K was decreased (47+/-5%, P<0.001). Also compared with remote regions, however, concentrations of Gd, Na, and K were not elevated after reperfusion in regions that were at risk but not infarcted (P=NS).

Conclusions: Regional elevations in myocardial MRI contrast agent concentrations are exclusively associated with irreversible ischemic injury defined histologically and by regional electrolyte concentrations.

Publication types

  • Evaluation Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Calcium / analysis
  • Chlorine / analysis
  • Chronic Disease
  • Contrast Media / analysis*
  • Electron Probe Microanalysis
  • Gadolinium DTPA / administration & dosage
  • Gadolinium DTPA / analysis*
  • Kinetics
  • Magnetic Resonance Imaging / methods*
  • Myocardial Infarction / diagnostic imaging*
  • Myocardial Infarction / metabolism
  • Myocardial Infarction / pathology*
  • Myocardium / chemistry
  • Phosphorus / analysis
  • Potassium / analysis
  • Rabbits
  • Radiography
  • Sodium / analysis
  • Sulfur / analysis


  • Contrast Media
  • Phosphorus
  • Chlorine
  • Sulfur
  • Sodium
  • Gadolinium DTPA
  • Potassium
  • Calcium