国产95式步枪所致猪肢体软组织贯通伤的MRI表现与病理学研究

Magnetic resonance imaging and pathology of soft tissues penetrating wounds in pig thigh shot by domestic-made 95 type rifle

目的分析猪肢体软组织枪伤后不同时间弹道及周围组织的MRI表现和病理学变化,为枪弹伤早期救治提供理论依据。方法将17只成年猪静脉麻醉后,取仰卧位,将右后肢悬吊固定于致伤架上,用国产95式步枪致伤,射击距离10m。于伤后2、6、12、24、48h及9、18d分别行MRI扫描和病理学检查。结果伤区组织的病理改变可分为原发弹道区、凝固性坏死区、碎裂区和变形区。凝固性坏死区宽1～3mm,在T2WI及增强T1WI上呈现"双低信号"现象;碎裂区和部分变形区呈现"双高信号"现象,但二者不能区分。结论国产95式步枪贯穿肢体软组织后伤区由内向外依次可分为原发弹道区、凝固性坏死区、碎裂区和变形区;MRI可清楚显示原发弹道和凝固性坏死区;碎裂区和变形区为围绕弹道外围的高信号区,病理组织学分界清楚。

Objective To analyze the magnetic resonance imaging（MRI） appearance and pathological changes of pig thigh of soft tissues after been shot by rifle,so as to offer a theoretical foundation for wound management in early stage of gunshot injuries.Methods Seventeen adult pigs were intravenously anesthetized and suspended in supine position,the pigs were shot in 10 meters away by domestic-made rifle of 95 type.The wound limb were undergone 1.5T MRI scans and histological observation at 2h,6h,12h,24h,48h,9day,and 18day after shot injury.Results The wounded tissues included four areas of different pathological changes：primary ballistic cavity,coagulative necrosis area,tissue disruption area and tissue distortion area.The thickness of coagulative necrosis area was about 1 to 3 millimeters,which showed double-hypointense signal phenomenon in both T2 weighted image and enhanced T1 weighted image.The tissue disruption area and part of tissue distortion area showed double-hyperintense signal phenomenon in both T2 weight image and enhanced T1 weighted image.Conclusion Penetrating gunshot wound in soft tissues of hind limb can be divided into four areas：primary ballistic cavity,coagulative necrosis area,tissue disruption area and tissue distortion area.MRI can clearly show primary ballistic cavity and coagulative necrosis area.Tissue disruption area and tissue distortion area are hyperintense signal areas on the outside of the primary ballistic cavity,which can be distinguished clearly by pathalogical observation,but tissue disruption area and part of tissue distortion area are undistinguishable by MRI.