Figure 9b. Through-plane strain information obtained with strain-encoded MR imaging. (a-c) Longitudinal shortening is displayed on a composite short-axis image (a) obtained by combining an image with low tagging frequency (b) and an image with high tagging frequency (c). Dyskinetic tissue with stretching (1 in a) is represented by a hyperintense area on the low-frequency image and by a hypointense area on the high-frequency image. Akinetic myocardial tissue (2 in a), in which there is no contraction, has an appearance identical to that of surrounding static tissue (ie, chest wall or liver). Severely hypokinetic tissue (3 in a) and normally contracting subendocardial or midwall tissue (4 and 5 in a) show an inverse intensity pattern directly related to the strain values on a pixel-by-pixel basis. (d-f) Short-axis strain-encoded MR images obtained in a 68-year-old woman after myocardial infarction. The low-frequency image (d) shows subendocardial hyperintense areas (arrows) that indicate myocardial dysfunction; the same areas are represented in red on the composite color-coded image (e). Delayed-enhancement image (f) shows a subendocardial area of hyperenhancement (arrows) in the region of the left anterior descending artery that represents chronic myocardial infarction and that corresponds with the areas of dysfunction depicted on the strain-encoded images.