Estimating the size of myocardial infarction by magnetic resonance imaging.
OBJECTIVE
To develop a method to measure myocardial infarct size by magnetic resonance imaging and to compare the results with pyrophosphate scanning by single photon emission computed tomography.


METHODS
All patients underwent magnetic resonance imaging and pyrophosphate scanning 5-7 days after the onset of symptoms. Both measurements of infarct size were compared with the release of creatine kinase MB and with ventricular performance estimated by radionuclide ventriculography.


METHODS
19 patients (age 40-68 years) who had sustained their first uncomplicated myocardial infarction and who had not been treated with thrombolytic therapy.


RESULTS
The site of infarction was clearly shown by both imaging techniques and was identical in each patient. The volume of infarcted tissue measured by magnetic resonance imaging agreed well with the infarct size measured by single photon emission tomography (mean difference 2.7 cm3). Correlations of both imaging techniques with the release of creatine kinase MB were best when total release rather than peak release was used. Both imaging techniques correlated closely with the subsequent ventricular performance.


CONCLUSIONS
Magnetic resonance imaging after acute infarction allows measurement of infarct size and this may prove useful in assessing new treatments designed to salvage myocardium.
Turnbull
L W
LW
University Department of Medical Radiology, Royal Infirmary, Edinburgh.
Ridgway
J P
JP
Nicoll
J J
JJ
Bell
D
D
Best
J J
JJ
Muir
A L
AL
D000328:Adult; D000368:Aged; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D007527:Isoenzymes; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000201:enzymology / Q000473:pathology*; D016698:Technetium Tc 99m Pyrophosphate; D015899:Tomography, Emission-Computed, Single-Photon
D007527:Isoenzymes; D016698:Technetium Tc 99m Pyrophosphate; D003402:Creatine Kinase