Results
Image quality
Total (weighted) image quality scores for both the AP and PA
projections, for each kVp increment, are presented in Table 3 and
Fig. 1. An image quality score of 48 was considered equal to the
reference image after weighting factors were applied.
The reliability of individual image quality scores between raters
must be considered. The ICC value for the five students was 0.85
(95% confidence interval, 0.72e0.94). An ICC value of 0.85, according
to Rosner (2011), indicates very good reproducibility.18
Magnification
The transverse diameter of the L3 vertebral body was 25 mm
and 27 mm for AP and PA projections, respectively. As a result the
PA projection demonstrated a magnification factor of 1.08 times
greater than the AP.