Q-space trajectory imaging (QTI): Enhanced specificity in diffusion MRI characterisation of hypertrophic mouse hearts ex vivo

Motivation: Adverse remodelling following aortic stenosis may be characterised by cardiomyocyte hypertrophy, disarray and/or increased fibrosis. Existing methods lack the specificity to distinguish between these features. Q-Space trajectory imaging (QTI) may help to overcome this limitation. Goal(s): To investigate the potential value of QTI in microstructural characterisation of hypertrophic hearts. Approach: QTI data were acquired and analysed in control and hypertrophic mouse hearts ex vivo. Results: Hypertrophic hearts exhibited higher mean diffusivity, and lower fractional anisotropy (FA), microscopic FA and anisotropic and total mean kurtosis relative to controls. This points primarily to cardiomyocyte hypertrophy rather than cell disarray or fibrosis. Impact: Q-space trajectory imaging has the potential to distinguish different microstructural features including cardiomyocyte hypertrophy, disarray and/or increased fibrosis seen in aortic stenosis and other pathologies, with greater specificity than existing techniques, and could lead to improved diagnosis and patient management.