Figure 4.

Optimization results for a kidney stone discrimination task and an iodine vs bone discrimination task. (a) and (e): The optimal dose allocation factor, A*, identified as the dose allocation that maximizes d^′ at each kVp pair. (b) and (f): Integral of the 3D NEQ (irrespective of task) demonstrates similar trends despite different values of w and A*. (c) and (g): The dual-energy contrast of brushite vs calcium phosphate and iodine vs bone, respectively, with (g) reflecting the K-edge of iodine at 33 keV (i.e., ∼65 kVp). (d) and (h): Detectability index as a function of kVp pair calculated using the optimal dose allocation, A*, shown in (a) and (e), respectively. The detectability index of the kidney stone discrimination task (d) shows the combined effect of NEQ (b) and contrast (c), whereas that of the iodine vs bone task (h) is mainly driven by contrast (g).