Table 2.

Performance of 4 acquisitions in average Hounsfield Unit (HU) value and standard deviation (SD) values on each ROI derived from uniformity module.

Angle (tube)	Center	Top	Left	Bottom	Right
CW: 5°–220° (No. 1)	−128.7 ± 6.8	−139.2 ± 13.6	−174.0 ± 16.5	−165.4 ± 11.3	−148.6 ± 12.8
CCW: 85°–230° (No. 1)	−135.3 ± 6.5	−194.7 ± 21.6	−134.3 ± 9.6	−137.5 ± 7.4	−200.2 ± 19.8
CW: 275°–130° (No. 2)	−79.4 ± 5.7	−100.5 ± 13.7	−87.9 ± 8.9	−81.9 ± 6.1	−93.4 ± 11.4
CCW:°355°–140° (No. 2)	−74.8 ± 6.2	−100.7 ± 14.7	−91.5 ± 10.5	−76.2 ± 5.6	−91.0 ± 10.9

CW, clock wise; CCW, counter clock wise.