Zhang Zhang, Presenter: Nothing to Disclose

Jing Yu, Abstract Co-Author: Nothing to Disclose

Ningnannan Zhang PhD, Abstract Co-Author: Nothing to Disclose

Dong Li MD, Abstract Co-Author: Nothing to Disclose

Tielian Yu, Abstract Co-Author: Nothing to Disclose

Spectral CT renewed the interest of myocardial perfusion evaluation in clinic application, such as image quality improvement by virtual monochromatic spectral (VMS) images, and iodine quantification by material decomposition. The current study was to investigate the ability of cardiac spectral CT for assessing myocardial infarction.

A total of 12 swine underwent 90 minutes occlusion on distal segment of LAD by balloon angioplasty. After 4±1 days of successful acute myocardial infarction model establishment, spectral CT coronary angiogram (CTCA, Discovery CT750 HD CT FREEdom Edition scanner: GE Healthcare, Milwaukee, WI, USA) and late gadolinium-enhanced magnetic resonance (MR, Signa HDx 3.0 Tesla MR scanner, GE, Milwaukee, WI, USA) was performed to evaluate myocardial infarction. The differences of attenuation density (AD), iodine concentration, and spectral curve among different myocardial regions were observed. The infarction on late gadolinium-enhanced MR and CTCA were visually assessed for each myocardial segment on a binary scale and compared by kappa test. Diagnostic ability of CTCA to differentiate infarct segments was tested by ROC curve.

Significant differences of both AD and iodine concentration on CTCA were found among infarction, risk area and remote myocardium on all three types of image settings (70keV, high voltage, and iodine density images; p<0.05). There were also significant differences slopes of spectral curve among infarction, risk area and remote myocardium. The spectral CT and MR had almost perfect agreement (κ=0.821) in infarct segment differentiation. ROC curve showed high diagnostic accuracy of CTCA to differentiate myocardial infarct segments (sensitivity=0.813, specificit= 0.989, positive predictive value=0.981, negative predictive value=0.880 and accuracy=0.901; p<0.001).

The 70keV VMS with higher SNR, CNR and lower noise was preferable to assess acute myocardial infarction. AD and iodine concentration on spectral CTCA, which had a good agreement with the standard MR results, could be used to differentiate infarct myocardial segments.

Spectral CTCA may have the potential ability to differentiate infarction, risk area and remote myocardium by using VMS, iodine quantification, and spectral curve in the clinics.

Zhang, Z, Yu, J, Zhang, N, Li, D, Yu, T, Cardiac Spectral CT: Iodine Quantification and Spectral Curve of Acute Myocardial Infarction in Swine.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007692.html