The Application Of Computed Tomography(CT) In Forensic Appraisal Of Injury Manner

Objective:To discuss the value of CT used as an assistant or substitute tool for autopsy and its superiority and defect in the forensic appraisal of injury manner. To explore the morphologic character in CT image of craniocerebral injury and its utility in estimation of injury manner,and provide the reliable stuff for the research of Finite Element Analysis for craniocerebral injury.Methods:10 cadavers dead form mechanical injury were selected, and examination of cadavers surface was performed then did the CT examination. The whole body from the cupular part to feet was scanned, and the main parameter were 120KV,380～400mA,420ms,width of collimating element 0.625mm, pitch 0.3mm, then the primary diagnosis was made after the scan. The 3D-reconstruction was performed in the work station if there was a suspect of fracture.The next day, autopsy was done under the guide of CT diagnosis then the diagnosis between CT and autopsy was compared. The superiority and defect between CT and autopsy examination in cadaver were compared from aspects of bone, soft tissue and organ injury.Using above-mentioned method, we put it in forensic medicine practice in the estimation of injury manner of 1 case dead from road traffic accident, and analyzed the real value of CT in such cases.91 craniocerebral injury cases which suffered from crinial bone fracture or(and) intracranial hemorrhage, cerebral contusion and intracerebral hemorrhage were collected, and their injury manner, CT image and other case history were documented, then the relation between the impact part and the skull fracture,brain contusion and laceration were analyzed.Results:CT examination before autopsy could reduce the missed diagnosis when the fracture occurred in the place where the routine autopsy didn't care.CT was sensitive to the pneumatosis and foreign object in the dead body while autopsy couldn't detect them or illustrated them under an inferior effect.CT was inferior in diagnosing injury which couldn't form X-ray density difference such as the entorrhagia of soft tissue and organ rupture.CT could demonstrate all kinds of fracture in situ before autopsy and it had a perfect 3D effect.It could display the interested skeletal part though controlling the window width and window level to provide better visual effect.Based on the diagnosis of the tiny fracture and the reverting of its morphologic character clearly, CT had special superiority in the analysis of injury manner.Among all the cases, the majority of the craniocerebral injury was skull fracture when suffered the force form frontal plane, but the intracranial hemorrhage,cerebral contusion or complex injury was more common when occiput suffered force.Fracture of facial cranium bones often caused by direct force,but the fracture of temporal bone was common seen when suffer the distally transmitted force.There was no significant difference in the incidence of basal fracture between groups which suffered different force direction. Among the cases due to falling injury, the incidence of contusion and laceration of brain was high when suffered the lateral or posterior force, while the force came from anterior part of the head, the incidence was low and often occurred in the intracalvarium near the impact part.Conclusions:CT can act as guidance and supplement for autopsy, and in case of the autopsy is not allowed, CT could act as a substitution especially for the appraisal of injury manner. But CT can't detect the skin destruction and soft tissue injury clearly, so it can't absolutely take place of the autopsy in all cases.To explore the consequence of head injury due to different force, vulnerant and injury manner through investigation by questionnaire is helpful to deeply reveal the vitodynamic character of head injury, and serve for the estimation of the vulnerant and injury manner.