Dual-energy CT for the assessment of chronic myocardial infarction in patients with chronic coronary artery disease: comparison with 3-T MRI.
OBJECTIVE
The purpose of this article is to compare the performance of dual-energy CT with that of 3-T MRI with late enhancement for the detection of chronic myocardial infarction during first-pass coronary CT angiography (CTA).


METHODS
Thirty-six patients underwent coronary CTA for the assessment of coronary bypass graft patency on a first-generation dual-source CT scanner in dual-energy mode. Gray-scale images (100 kV, 140 kV, and blended virtual 120 kV) were assessed for areas of hypodense myocardium during the arterial phase. In addition, a color-coded map of myocardial iodine distribution was calculated from the dual-energy data for perfusion analysis. Dual-energy CT data were compared with data from 3-T MRI with late enhancement, which served as the reference standard for scar detection using the American Heart Association's 17-segment model of the left ventricle.


RESULTS
One hundred one (17%) of 612 myocardial segments in 22 (61%) of 36 patients showed late enhancement on MRI. Although myocardial iodine mapping was prone to artifacts, mostly arising from sternal wires (70% sensitivity), 100-kV gray-scale images showed the highest sensitivity (80%) for the detection of myocardial scar. Blended virtual 120-kV images with lower noise and higher resolution had the best diagnostic accuracy (77% sensitivity, 97% specificity, 85% positive predictive value, 96% negative predictive value, and 94% accuracy).


CONCLUSIONS
Detection of chronic myocardial infarction on color-coded iodine distribution analysis with first-generation dual-energy CT is impeded by thoracic metallic devices. This group of patients benefits more from adequate blending of high- and low-kilovoltage gray-scale images. Further technical improvements are desirable to lower artifact burden and improve sensitivity on myocardial iodine distribution mapping.
Bauer
Ralf W
RW
Department of Diagnostic and Interventional Radiology, Clinic of the Goethe University, Haus 23C UG, Theodor-Stern-Kai 7, Frankfurt am Main 60590, Germany. ralfwbauer@aol.com
Kerl
J Matthias
JM
Fischer
Nadine
N
Burkhard
Thorsten
T
Larson
Maya C
MC
Ackermann
Hanns
H
Vogl
Thomas J
TJ
D000328:Adult; D000368:Aged; D016477:Artifacts; D002908:Chronic Disease; D003287:Contrast Media; D017023:Coronary Angiography; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D004562:Electrocardiography; D005260:Female; D005682:Gadolinium; D006571:Heterocyclic Compounds; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007479:Iopamidol / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D009942:Organometallic Compounds; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C062402:gadoteridol; C057937:iomeprol; D005682:Gadolinium; D007479:Iopamidol