Figure 1
Cardiac MR images depicting intramyocardial fat in a 21-year-old female with Proteus syndrome. (a) Short axis cine image of a midventricular slice shows some areas of low signal intensity within the right ventricular (RV) trabeculae (arrowhead) and RV side of the interventricular septum (arrow) secondary to areas of chemical shift artifact caused by the presence of small areas of fat in the myocardium. Short-axis cardiac optimized multi-echo Dixon water (b) and fat (c) separation images of a mid-ventricular slice. (b) Short axis water image of the mid heart shows areas of intramyocardial fat as low signal intensity, for example within the RV trabeculae (arrowhead) and along the RV side of the interventricular septum (arrow). The fat image (c) shows areas of high signal intensity compatible with fat within the RV trabeculae (arrowhead) and RV endocardial side of the interventricular septum (arrow). (d) CT image of the chest confirms areas of fat within the RV side of the interventricular septum and right ventricular free wall of the heart (arrows). Patterns of intramyocardial fat are depicted on (e–g). Short axis water image (e) of a mid LV slice shows areas of midwall (thick arrow) and subendocardial (arrowhead) fat in the left ventricle as areas of low signal intensity. There is also fat involving the RV free wall (thin arrow). A corresponding fat image (f) shows the midwall (thick arrow), subendocardial (arrowhead), and RV wall fat (thin arrow) as areas of high signal intensity. Note that the subendocardial fat which is difficult to appreciate on the water image because of its similar signal intensity to the blood pool is very obvious on the fat image. (g) Short axis fat image of the mid LV shows a transmural area of high signal intensity corresponding to transmural fat within the septal wall (arrow). (h) Short axis fat image of a mid LV slice shows areas of fat as high signal intensity in several distributions: epicardial in the inferior wall (thin arrow), endocardial on the RV side of the interventricular septum (thick arrow) and endocardial on the LV side of septal wall (arrowhead).
