Abstract 20048: Temporal and Spatial Characteristics of the Area at Risk Investigated using Computed Tomography and T1-weighted Magnetic Resonance Imaging
Introduction: Cardiovascular magnetic resonance (CMR) imaging can measure the myocardial area at risk (AAR), but the technique has received criticism for inadequate validation. Also, CMR commonly depicts an AAR that is wider than the endocardial surface length of the infarct, which in turn would require a lateral perfusion gradient within the AAR. Our aim was to investigate the presence of a lateral perfusion gradient and to validate CMR for detection of the AAR against independent reference standards of high quality.
Methods: Multiple time points of computed tomography (CT) perfusion imaging and myocardial microsphere blood flow analysis were used to investigate the lateral perfusion gradient in a canine model (n=10) of ischemia and reperfusion. AAR by T1-weighted 3-T CMR was compared to AAR by CT perfusion imaging, microsphere blood flow analysis and pathology.
Results: The lateral portion of the AAR was found to be perfused to a higher degree than the core of the AAR when measured by CT perfusion imaging (40.7±11.8 vs 25.2±17.7 HU, lateral vs core, p=0.0008) and microsphere blood flow (0.11±0.04 vs 0.05±0.02 ml/g/min, lateral vs core, p=0.001). Measurements of the AAR by CMR correlated well with CT perfusion (R2=0.80), microsphere blood flow (R2=0.80) and pathology (R2=0.74) and had good limits of agreement (-0.79±4.02 % of the left ventricular mass (LVM) versus CT; -1.49±4.04 %LVM versus microspheres and -1.01±4.18 %LVM versus pathology).
Conclusions: A lateral perfusion gradient exists within the AAR. T1-weighted CMR accurately quantifies size of the AAR with excellent agreement compared to independent reference standards of high quality.
Author Disclosures: J. van der Pals: None. S. Hammer-Hansen: None. S. Nielles-Vallespin: None. P. Kellman: None. J. Taylor: None. S. Kozlov: None. L. Hsu: None. M.Y. Chen: Other Research Support; Significant; Toshiba. A.E. Arai: Other Research Support; Significant; Siemens, Toshiba.
- © 2014 by American Heart Association, Inc.