Fig. 7
Maximum computed tomography (CT) numbers from the edge at 120 kVp (a) and at 140 kVp (b) and the 120/140 DEImax calculated from CT numbers obtained from edge measurements (c). Only the lodged Action 4 copper bullet in cases 2 and 5 demonstrated far lower maximum CT numbers than the lodged .22 LR lead bullets in cases 1, 3, and 4. However, the Action 4 copper bullet in case 6 did not differ from the lead bullets at either 120 kVp (a) or 140 kVp (b). At 120 kVp, for the Action 4 copper bullet, values very close to the upper limit of the extended CT scale (ECTS) represented as red-dashed line were reached. In contrast, all Action 4 copper bullets clearly differed from the .22 LR lead bullets in terms of the dual-energy index (DEI) and obtain DEIs above the threshold of 0.004 represented as green dashed line defined by the results of the animal cadaver study. Even the Action 4 copper bullet in case 6 clearly differed from the lead bullets in terms of the DEI, which was calculated from CT numbers that were not obviously different from those of lead bullets at 120 and 140 kVp.