Fig. 2

The methods used to quantify infarct size based on late gadolinium enhancement (LGE) are illustrated. The top row depicts the steps for automated methods for infarct border determination without (AUTO) and with user correction (AUTO-UC). Two commonly used techniques for signal thresholding were used, the “Segment”-algorithm (AUTO _Segment ) and the “full-width at half maximum” (FWHM) technique (AUTO _FWHM). Note that automated methods still require manual delineation of the myocardial (endocardial/epicardial) borders. The middle row depicts the steps for manual planimetry of the infarct. For MANUAL, readers were instructed to include any myocardium that appeared hyperenhanced, whether fully bright or partially bright (e.g. grey). For MANUAL-ISI, adjustments were made for intermediate signal intensities (ISI) in that half of grey regions were included (along with 100% of fully bright regions). The bottom row depicts visual scoring methods, which were based on the conventional 17-segment model. For VISUAL, the spatial extent (area) of hyperenhancement was considered, whereas for VISUAL-ISI, the spatial extent and the signal intensity of hyperenhancement were both considered. No-reflow zones were considered fully bright similar to that for MANUAL-ISI. Typical scores in a patient example are shown (A = hyperenhancement area; SI = hyperenhancement signal intensity)