Institut für Rechtsmedizin, Universität Bonn, Bonn 53111, Germany.
Int J Legal Med. 2012 Jan;126(1):37-42. doi: 10.1007/s00414-010-0546-1. Epub 2011 Mar 25.
The temporary cavity of a missile produces radial tears in ordnance gelatine, which correlate to the energy transfer. Computed tomography is a useful and non-destructive method to examine gelatine blocks. However, the tears give only few radiocontrast by air filling, which decreases with the time past shooting. Therefore, systematically, a radiocontrast material was searched to enhance the contrast. Different contrast materials were amalgamated to acryl paint, and about 7 g was sealed in a foil bag, which was integrated in the front of a standard 10% gelatine cylinder. Shots with Action-5 expanding bullets were performed from a 5-m distance. Gelatine was scanned by multi-slice computed tomography. The multiplanar reconstructed images were compared to mechanically cut slices of 1 cm thickness. It was shown experimentally that iodine containing water-soluble contrast material did not give sufficient contrast and caused diffusion artefacts. Best results were obtained by barium sulphate emulsion. The amount of acryl paint was sufficient to colour the tears for optical scanning. The radiocontrast of barium leads to satisfying imaging of tears and allowed the creation of a three-dimensional reconstruction of the temporary cavity. Comparison of optical and radiological results showed an excellent correlation, but absolute measures in computed tomographic (CT) images remained lower compared with optically gathered values in the gelatine slices. Combination of paint and contrast material for CT examination will facilitate the evaluation of complex ballistic models and increase accuracy.
导弹的瞬时空腔会在发射药明胶中产生径向撕裂，这与能量传递有关。计算机断层扫描是一种有用且非破坏性的方法，可以检查明胶块。然而，撕裂只会通过空气填充产生少量的射线对比，并且随着射击时间的过去而减少。因此，系统地寻找一种射线对比材料来增强对比度。不同的对比材料与丙烯颜料混合，并将约 7 克密封在箔袋中，该箔袋集成在标准 10%明胶圆柱体的前部。从 5 米的距离用 Action-5 扩张弹射击。明胶通过多层计算机断层扫描进行扫描。将多平面重建图像与 1 厘米厚的机械切割切片进行比较。实验表明，含碘水溶性对比材料没有提供足够的对比度，并产生扩散伪影。硫酸钡乳剂的效果最好。丙烯颜料的量足以使撕裂处着色，以便光学扫描。钡的射线对比导致撕裂的成像令人满意，并允许创建临时空腔的三维重建。光学和放射学结果的比较显示出极好的相关性，但与在明胶切片中光学采集的值相比，计算机断层扫描（CT）图像中的绝对测量值仍然较低。油漆和对比材料的组合用于 CT 检查将有助于评估复杂的弹道模型并提高准确性。
