Alexia Rossi MD, Presenter: Nothing to Disclose

Ernst Klotz PhD, Abstract Co-Author: Employee, Siemens AG

Daphne Merkus, Abstract Co-Author: Nothing to Disclose

Andre G. Uitterlinden PhD, Abstract Co-Author: Nothing to Disclose

Pim J. De Feyter MD, PhD, Abstract Co-Author: Nothing to Disclose

Dirk Duncker MD, PhD, Abstract Co-Author: Nothing to Disclose

Gabriel P. Krestin MD, PhD, Abstract Co-Author: Consultant, General Electric Company Research Grant, General Electric Company Research Grant, Bayer AG Research Grant, Siemens AG

To quantify regional changes of several myocardial perfusion parameters at different levels of coronary flow using ECG-triggered dynamic contrast enhanced CT(DCE-CT) and to study the predictive and discriminatory power of these myocardial perfusion parameters.

In seven pigs, an adjustable hydraulic occluder was placed around the LAD to induce various degrees of coronary flow reduction. Twenty-eight (28) scans were performed under maximum adenosine vasodilatation (no obstruction and flow reduced by 12% to 90%). Dynamic data were acquired for the whole heart after bolus injection using a dedicated ECG-triggered scan mode on a dual-source CT. Using a two-compartment deconvolution technique 3D-maps of myocardial blood flow (MBF), first pass distribution volume (FPDV), perfused capillary blood volume (PCBV) and flowextraction-product (FE) were calculated. All parameters were measured in the downstream LAD area and were correlated with relative input flow.  

MBF (baseline 257±27 ml/100ml/min, r=0.78, slope=0.66), FPDV (baseline 24.6±2.8 ml/100ml, r=0.84, slope=0.76) and PCBV (baseline 16.2±4.6 ml/100ml, r=0.78, slope=0.83) significantly decreased proportional to the reduction of coronary flow in the LAD (p<0.0001). FE (baseline 106±19 ml/100ml/min) on the other hand remained constant until coronary flow was reduced to less than 30%. FE values below 30% coronary flow were significantly lower than FE values above 30% (Mann-Whitney, p<0.01).   

DCE-CT is suitable for the assessment of regional myocardial perfusion parameters and can be used to study microcirculatory changes at various degrees of clinically relevant coronary flow reductions. Additional perfusion parameters appear to improve differential diagnostic performance of DCE-CT in a large animal model.

DCE-CT has successfully been used in animal models but stress MBF values appear to be lower than physiologically expected.

Rossi, A, Klotz, E, Merkus, D, Uitterlinden, A, De Feyter, P, Duncker, D, Krestin, G, Regional Changes of Several Myocardial Perfusion Parameters at Different Levels of Coronary Flow by Dynamic Perfusion CT.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043615.html