Figure 15.

Modulation transfer function (MTF) of cone beam CT devices. (a) MTF of four protocols in three devices; (b) MTF with “default” and “wPMMA” settings. In Figure 15a, abbreviations are the same as in Table 2. In Figure 15b, “default” is when the inserts are in the default setting according to the manual. “wPMMA” is when other holes were occupied by uniform PMMA inserts. Other abbreviations are the same as in Table 2