Impact of contrast material volume on quantitative assessment of reperfused acute myocardial infarction using delayed-enhancement 64-slice CT: experience in a porcine model.
OBJECTIVE
Our purpose in this study was to compare the impact of contrast material volume in delayed-enhancement computer tomography (CT) imaging for assessing acute reperfused myocardial infarction.


METHODS
In five domestic pigs (20-30 kg), the circumflex coronary artery (CX) was balloon-occluded for 2 h followed by reperfusion. After 5 days, CT imaging was performed after intravenous administration of iodinated contrast material (Iomeprol 400 mgI/ml; Bracco, Italy). A 64-slice multidetector CT (MDCT) (Sensation 64, Siemens) scanner was used for imaging, with standard angiography characteristics. Three scans were performed: first, coronary angiography at first pass with 1.25 gI/kg of contrast material (ART); and remaining delayed-enhancement (DE(1)-DE(2)) 15 min after administration of 1.25 (DE(1)) and 15 min after additional administration of 2.50 gI/kg (=total 3.75 gI/kg - DE(2)). Mean heart rate decreased to 51+/-9 bpm after intravenous administration of Zatebradine (10 mg/kg). Data sets were reconstructed during the end-diastolic phase of the cardiac cycle. Areas of infarction-enhanced (DE), no-reflow (no-reflow) and remote myocardial [remote left ventricle (LV)] were manually contoured. CT attenuation values (Hounsfield units) were measured using five regions of interest: DE, no-reflow, remote LV, left ventricular cavity (lumen LV) and in air. Differences, correlations, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated.


RESULTS
We found significant differences between the attenuation of DE, no-reflow and remote LV (p<0.001). DE and no-reflow size were assessed accurately with DEMDCT. In particular, SNR and CNR showed higher values in DE(2) (approximately 6.0 and 3.5, respectively; r(2)=0.90) vs. DE(1) (approximately 4.0 and 2.2, respectively; r(2)=0.85).


CONCLUSIONS
The increase of contrast material volume determines a significant improvement in myocardial infarction image quality with DE-MDCT.
Martini
C
C
Department of Radiology and Cardiology, c/o Piastra Tecnica-Piano 0, Azienda Ospedaliero-Universitaria, Parma, Italy.
Maffei
E
E
Palumbo
A
A
Weustink
A
A
Baks
T
T
Moelker
A
A
Dunker
D
D
Emiliano
E
E
Cuttone
A
A
Mollet
N
N
Krestin
G
G
De Feyter
P
P
Cademartiri
F
F
D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage*; D004195:Disease Models, Animal; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D009203:Myocardial Infarction / Q000000981:diagnostic imaging*; D015425:Myocardial Reperfusion; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D034421:Sus scrofa; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol