Myocardial ECV Imaging by MRI Compared to Myocardial ECV Imaging by CT Validation in Experimental Acute Myocardial Infarction

Martin Ugander¹, Marcus Y Chen¹, Billy Chen¹, Li-Yueh Hsu¹, Peter Kellman¹, Andrew E Arai¹

The myocardial extracellular volume fraction (ECV) can by quantified by MR. However, independent validation is lacking. We performed ECV imaging by MR (1.5T) and CT (320 channel) in experimental acute myocardial infarction. ECV was quantified using hematocrit and T1 or Hounsfield unit quantification in tissue and blood before and after Gd-DTPA or iodinated contrast injection for MR and CT, respectively. ECV in remote, infarcted and peri-infarction myocardium by CT and MR correlated (R2=0.76, p<0.001, y=0.92x+0.08, MR bias 4.78.3 percentage points, n=17 measures in 6 dogs). CT provides independent validation that MR can be used to quantitatively image myocardial ECV.