Probability density plots for the two canine studies (A) and (B) are shown. For each case the empirical densities of the adenosine and stenosis myocardial signals are plotted in red and green bars, respectively. Overlaid are the maximum likelihood estimated Student-T densities for each signal. Finally, the threshold is shown in blue at 143.3 for study A, 189.7 for study B, respectively. Note that m – s is the threshold computed from the Student-T distribution fitted to the adenosine signal as described in the text. All intensities below this threshold are color-coded in hues of red, while intesities above this threshold are color-coded in hues of yellow.