Diagnostic value of contrast-enhanced magnetic resonance imaging and single-photon emission computed tomography for detection of myocardial necrosis early after acute myocardial infarction.
OBJECTIVE
This study sought to evaluate the diagnostic value of contrast-enhanced magnetic resonance imaging (CMR) and single-photon emission computed tomography (SPECT) for detection of myocardial necrosis after acute myocardial infarction (AMI).


BACKGROUND
Single-photon emission computed tomography is widely accepted in the clinical setting for detection and estimation of myocardial infarction. Contrast-enhanced magnetic resonance imaging offers technical advantages and is therefore a promising new method for identification of infarcted tissue.


METHODS
Seventy-eight patients with AMI were examined by CMR and SPECT 7 days after percutaneous coronary intervention. Contrast-enhanced magnetic resonance imaging and SPECT images were scored for presence and location of infarction using a 17-segment model. Results were compared with the peak troponin T level, electrocardiographic, and angiographic findings.


RESULTS
Acute myocardial infarction was detected significantly more often by CMR than SPECT (overall sensitivity: 97% vs. 87%; p = 0.008). Sensitivity of CMR was superior to SPECT in detecting small infarction as assessed by the peak troponin T level <3.0 ng/ml (92 vs. 69%; p = 0.03), and infarction in non-anterior location (98% vs. 84%; p = 0.03). Non-Q-wave infarctions were more likely to be detected by CMR (sensitivity 85% vs. 46%; p = 0.06). While CMR offered high sensitivity for detection of AMI irrespective of the infarct-related artery, SPECT was less sensitive, particularly within the left circumflex artery territory.


CONCLUSIONS
Contrast-enhanced magnetic resonance imaging is superior to SPECT in detecting myocardial necrosis after reperfused AMI because CMR detects small infarcts that were missed by SPECT independent of the infarct location. Thus, CMR is attractive for accurate detection and assessment of the myocardial infarct region in patients early after AMI.
Ibrahim
Tareq
T
Deutsches Herzzentrum and 1. Medizinische Klinik Rechts der Isar, Technische Universität München, München, Germany. T.Ibrahim@lrz.tu-muenchen.de
Bülow
Hubertus P
HP
Hackl
Thomas
T
Hörnke
Mira
M
Nekolla
Stephan G
SG
Breuer
Martin
M
Schömig
Albert
A
Schwaiger
Markus
M
D000368:Aged; D015331:Cohort Studies; D003287:Contrast Media; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D009206:Myocardium / Q000473:pathology*; D009336:Necrosis / Q000473:pathology; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
D003287:Contrast Media; D017256:Technetium Tc 99m Sestamibi