%0 Journal Article
%T Reproducibility of in-vivo diffusion tensor cardiovascular magnetic resonance in hypertrophic cardiomyopathy
%A McGill Laura-Ann
%A Ismail Tevfik F
%A Nielles-Vallespin Sonia
%A Ferreira Pedro
%J Journal of Cardiovascular Magnetic Resonance
%D 2012
%I BioMed Central
%R 10.1186/1532-429x-14-86
%X Background Myocardial disarray is an important histological feature of hypertrophic cardiomyopathy (HCM) which has been studied post-mortem, but its in-vivo prevalence and extent is unknown. Cardiac Diffusion Tensor Imaging (cDTI) provides information on mean intravoxel myocyte orientation and potentially myocardial disarray. Recent technical advances have improved in-vivo cDTI, and the aim of this study was to assess the interstudy reproducibility of quantitative in-vivo cDTI in patients with HCM. Methods and results A stimulated-echo single-shot-EPI sequence with zonal excitation and parallel imaging was implemented. Ten patients with HCM were each scanned on 2 different days. For each scan 3 short axis mid-ventricular slices were acquired with cDTI at end systole. Fractional anisotropy (FA), mean diffusivity (MD), and helix angle (HA) maps were created using a cDTI post-processing platform developed in-house. The mean ¡À SD global FA was 0.613 ¡À 0.044, MD was 0.750 ¡À 0.154 ¡Á 10-3 mm2/s and HA was epicardium  34.3 ¡À 7.6¡ã, mesocardium 3.5 ¡À 6.9¡ã and endocardium 38.9 ¡À 8.1¡ã. Comparison of initial and repeat studies showed global interstudy reproducibility for FA (SD = ¡À 0.045, Coefficient of Variation (CoV) = 7.2%), MD (SD = ¡À 0.135 ¡Á 10-3 mm2/s, CoV = 18.6%) and HA (epicardium SD = ¡À 4.8¡ã; mesocardium SD = ¡À 3.4¡ã; endocardium SD = ¡À 2.9¡ã). Reproducibility of FA was superior to MD (p = 0.003). Global MD was significantly higher in the septum than the reference lateral wall (0.784 ¡À 0.188 vs 0.750 ¡À 0.154 x10-3 mm2/s, p < 0.001). Septal HA was significantly lower than the reference lateral wall in all 3 transmural layers (from  8.3¡ã to  10.4¡ã, all p < 0.001). Conclusions To the best of our knowledge, this is the first study to assess the interstudy reproducibility of DTI in the human HCM heart in-vivo and the largest cDTI study in HCM to date. Our results show good reproducibility of FA, MD and HA which indicates that current technology yields robust in-vivo measurements that have potential clinical value. The interpretation of regional differences in the septum requires further investigation.
%K Hypertrophic cardiomyopathy
%K Diffusion tensor imaging
%K Diffusion weighted imaging
%K Cardiovascular magnetic resonance
%K Disarray
%U http://jcmr-online.com/content/14/1/86