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. Author manuscript; available in PMC: 2017 May 7.
Published in final edited form as: Phys Med Biol. 2016 Apr 1;61(9):3365–3386. doi: 10.1088/0031-9155/61/9/3365

Figure 7.

Figure 7

Comparisons of the (left) bias and standard deviation of mean uptake values and (right) their MSEs for 10-mm spheres located axially ¼ off-center in the simulated phantom for analytic- and iterative-DIRECT, both with and without resolution models (RM). SUV bias-vs.-std results and MSE values are shown for variable levels of regularization using spectral apodizing (Cosine) filters of various strengths (with the cut-off parameter increasing from (left) 0.4 times the Nyquist frequency to (right) no filtering) for analytic-DIRECT and various iteration numbers (5–100, from left to right) for iterative-DIRECT for 16M, 4M, and 1M counts (top to bottom). Areas I and II in the top-left plot correspond to images illustrated in figure 8.