Abstract 13060: Clinical Factors Affecting Interpretation of Left Ventricular Fractional Anisotropy Obtained from ex-vivo Diffusion Tensor Magnetic Resonance Imaging
Purpose: Diffusion-weighted cardiac MRI has the potential to non-invasively quantify the architecture of myofibers. However, the impact of clinical factors on fibre architecture has not been explored. We aimed to assess the relationship between myocardial fiber orientation and clinical variables.
Materials and Methods: DTI was performed with a 3T MRI (Achieva, Philips) on 24 cadaveric human hearts (13 female, mean age 61+17 years). Fractional anisotropy (FA) was measured (DTIStudio v. 3.0.2) at four locations in the LV base and then averaged. Univariable linear regression analysis was performed to identify predictors of FA. Tested variables included: age, race, gender, body-mass index, left ventricular mass, left ventricular volume, and total cardiac mass. P-values ≤0.05 were considered significant.
Results: The only variable that was significantly correlated with FA was body-mass index (Table). FA increases due to increased diffusivity in a single direction with increasing body-mass index.
Conclusions: This is the first study to use diffusion weighted MRI to show that increasing body-mass index is associated with increasing FA values. Cardiac DTI has the potential to provide novel insights into how cardiac function is affected by changes in myofiber architecture. However, interpretation of these studies may require adjustment for patient body-mass index.
- © 2013 by American Heart Association, Inc.