# Multi-Modality Cardiovascular Imaging Assessment in Fabry Disease
## 7 Future Imaging  
Cardiovascular imaging does not stand still, and there are many future developments that have huge potential in improving diagnosis, characterizing disease progression and selecting patients for appropriate treatment. T1 mapping has been an advance in early disease identification but is not all encompassing with a proportion of patients with normal T1 having other features that are subtle to suggest myocardial involvement. Finding a reliable method of characterizing these patients, or improving selection of patients for therapy, will require large scale studies with long-term follow-up. Future imaging modalities that may be relevant include shear wave elastography on high frame rate echocardiography or diffusion tensor imaging on CMR.  
Shear wave elastography (SWE) has been used to assess stiffness within a tissue by measurement of propagation velocity of externally induced shear waves [72]. Shear-like waves have also been shown to naturally occur within myocardial tissue as a result of the impulse formed from closure of the mitral and aortic valve [73]. These can be measured using high rate TDI [74]. In a prospective study comparing normal volunteers with patients with HCM, shear wave velocities were measured using high frame rate TDI on TTE. The study demonstrated significantly higher shear wave velocities in the myocardium of HCM patients compared with normal volunteers which correlated with the E/e' ratio.  
A clinical trial is currently underway to investigate the beneficial role of myocardial elastography as an assessment of myocardial stiffness in patients with FD and cardiac amyloidosis using a multifrequency convex transducer under specific adjustment to perform myocardial elastography [75]. SWE may provide a method of assessing for early diastolic changes in FD that could indicate early cardiomyopathy influencing decisions regarding commencement of disease-modifying treatment at an earlier stage.  
Diffusion tensor CMR (DT-CMR) is an emerging tool providing a non-invasive assessment of microstructural cardiomyocyte organisation by assessing diffusion of water [76]. DT-CMR measures the effect of the cardiac microstructure on diffusion of water to gain information about myocardial organisation. Histological characteristics of HCM include cardiomyocyte disarray. DT-CMR provides a non-invasive technique of differentiating HCM phenotypes [77]. Within DT-CMR, measurement of apparent diffusion coefficient and the fractional anisotropy allow for quantification of disarray [78]. DT-CMR may provide  
Figure 10: The 2D TTE MR assessment in an adult with advanced Fabry cardiomyopathy and coexisting end stage renal disease. (**Left**) Parastermal long axis view demonstrating LVH, left atrial dilatation, bilateral annular calcification of the mitral valve (causing basal restriction) with moderate MR evident on colour Doppler and vena contracta of 0.4 cm (moderate); (**Middle**) Apical 4-chamber view demonstrating bilateral annular calcification of the mitral valve with MR on colour Doppler and proximal isovelocity surface area (PISA) measurement of 0.3 cm (moderate); (**Right**) Apical 4-chamber view demonstrating moderate MR on colour Doppler.  
assessment of myocardial organisation and degree of disarray particularly in the early stages of sphingolipid accumulation in FD.  
The use of AI in the detection of HCM using a 12-lead ECG has been demonstrated using AI-based convolutional neural networks (CNN) distinguishing HCM from non-HCM cases with low false-positive rates and good negative predictive value [79]. Future work could involve using CNN in the initial identification of FD using ECG criteria alongside automated echocardiography interpretation.