Signal Intensity of Myocardial Scars at Delayed-enhanced MRI.
Acta Radiol. 2009 May 15; 1-6Themudo RE, Johansson L, Ebeling-Barbier C, Lind L, Ahlstrom H, Bjerner TBackground: Traditionally, unrecognized myocardial infarction (UMI) is defined as the appearance, in a non-acute setting, of a new diagnostic Q wave. In the recent past, delayed-enhanced magnetic resonance imaging (DE-MRI) has provided a new imaging method for evaluating myocardial viability and to detect myocardial scars. Purpose: To investigate differences in tissue characteristics between UMI and recognized myocardial infarction (RMI) scars, by assessing the signal intensity (SI) detected by DE-MRI. Material and Methods: A randomized subgroup of 259 subjects from the Prospective Investigation of the Vasculature of Uppsala Seniors (PIVUS) study was submitted to cardiac magnetic resonance imaging (MRI). DE-MRI-detected myocardial scars were divided in two groups, UMI and RMI, according to the hospital medical records. The scars detected by DE-MRI were analyzed by measuring SI ratio of scar tissue to normal myocardium. Results: The mean SI ratio in the UMI group (4.5+/-3.0, mean+/-SD) was lower than in the RMI group 8.9+/-5.1 (P-value = 0.001). This difference was still significant (P
