Acute myocardial infarction: contrast-enhanced multi-detector row CT in a porcine model.
OBJECTIVE
To assess the role of contrast material-enhanced retrospectively electrocardiographically (ECG) gated multi-detector row computed tomography (CT) in the detection of acute myocardial infarction in a porcine model of total coronary occlusion.


METHODS
Seven Yorkshire farm pigs were studied with contrast-enhanced retrospectively ECG-gated multi-detector row CT 3 hours after total occlusion of the distal left anterior descending artery (n = 5) or the second diagonal branch (n = 2). Reformatted short-axis end-systolic and end-diastolic CT data sets were assessed for myocardial perfusion deficits, coronary occlusion, and abnormal myocardial wall motion. Perfusion deficits were compared with microsphere-determined blood flow and triphenyltetrazolium chloride (TTC)-stained tissue samples for infarct assessment by using Bland-Altman analysis and analysis of variance.


RESULTS
Myocardial perfusion deficits, occlusion of the left anterior descending artery or second diagonal branch, and akinesis of the infarcted segment were identified in all five animals that completed the study. One animal died, and one data set had nondiagnostic image quality. The CT end-diastolic (mean, 16.1% +/- 4.8 [SD]; range, 8.6%-22.2%) and end-systolic (mean, 17.0% +/- 6.4; range, 8.7%-26.8%) volume of perfusion deficit was similar to that of infarcted tissue at TTC staining (mean, 13.6% +/- 6.0; range, 7.8%-30.9%). Infarcted myocardium at CT demonstrated a 76.1% reduction in microsphere-determined blood flow and a significant reduction of myocardial CT attenuation compared with normal myocardium (P <.01). Myocardial wall motion analysis demonstrated absence of systolic wall thickening in infarcted myocardium.


CONCLUSIONS
Multi-detector row CT with retrospective ECG gating permits the detection and further characterization of acute myocardial infarction in a porcine model of complete coronary occlusion.
Hoffmann
Udo
U
Department of Radiology, Division of Cardiology, Massachusetts General Hospital and Harvard Medical School, 100 Charles River Plaza, Suite 400, Boston, MA 02114, USA. uhoffman@partners.org
Millea
Ryan
R
Enzweiler
Christian
C
Ferencik
Maros
M
Gulick
Scott
S
Titus
Jim
J
Achenbach
Stephan
S
Kwait
Dylan
D
Sosnovik
David
D
Brady
Thomas J
TJ
D000818:Animals; D003287:Contrast Media; D003326:Coronary Circulation; D004562:Electrocardiography; D005260:Female; D007091:Image Processing, Computer-Assisted; D008297:Male; D008863:Microspheres; D009200:Myocardial Contraction; D009203:Myocardial Infarction / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology; D009206:Myocardium / Q000473:pathology; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods
D003287:Contrast Media