Figure 6.

The spatial resolution in full width at half maximum (FWHM-mm) as a function of distance for both the LEHR and LEAP collimators. The data markers indicate the measured native resolution, which is only available in the daily quality control mode. The dash and dashed-dotted lines represent the nominal resolution, which is realized in the clinical protocol where a 4-mm Gaussian filter is applied to the image by default. The FWHM at 10 cm from the collimator was 7.2 mm for LEHR (manufacturer specification: 7.4 mm) and 8.9 mm for LEAP (manufacturer specification: 10.3 mm). The uncertainty in each data marker is <1%.