Role of X-Rays in Forensic Medicine

Role of X-Rays in Forensic Medicine

X-rays are the most common as well as essential imaging method used in the field of forensic medicine. The foreign bodies present in the body can be displayed and localized and helps to detect traumatic and pathological changes. It is used widely as it has the benefit of being a non-invasive evaluation technique. Thus, analysis before an autopsy can be done that will help in selecting the optimal strategy for dissection.

The ability to produce images using x-rays was an accidental discovery by Wilhelm Rontgen in 1895. His findings have been described as having a greater impact on medicine than any other in history. It was only a matter of weeks later that the forensic use of x-rays was tested, they helped convict an American attempted murderer and also in the UK. The main problems during that time were the amount of time it took to produce the images i.e.; up to 70 minutes, and the large associated radiation dose.  

With time newer techniques and technologies came into the picture especially computed tomography and magnetic resonance imaging. The application of these techniques extends the possibilities of the visualization of the bony structures towards more detailed imaging of the soft tissues and internal organs.

The application of modern imaging methods in postmortem body investigation is known as digital or virtual autopsy. Nowadays, digital postmortem imaging is preferred over the conventional autopsy technique.   

X-Rays in Forensic Medicine

• Techniques such as Fluoroscopy, General X-rays, MRI, NM, CT, CCT, Angiography, Venography, Dental Radiography are widely used in the field of forensic medicine.
• Forensic anthropologists and odontologists routinely rely on the comparison of antemortem and postmortem radiographic plates to establish identity.
• Postmortem MDCT scanning is useful in severely burned and charred bodies that are difficult to examine. It may help identify antemortem traumatic injury and aid in localizing tissue suitable for DNA analysis. Partial-thickness burns may produce no significant changes in the dermis or mild irregularity of the dermis on MDCT images. Full-thickness burns show loss of the dermal layer with exposure of the underlying fat and/or skeletal muscle that is typically irregular and jagged.
• The location of foreign bodies and gas emboli and documentation of fractures can be done using x-rays.
• It helps in the diagnosis of non-accidental injury in children and adults, in establishing medical negligence, and estimating biological age in disputed cases.
• X-ray method for detecting pathological features such as pneumothorax, pneumoperitoneum, barotrauma injuries, and air embolisms.
• Vertebral Angiography can be done for traumatic subarachnoid hemorrhage.
• When the body to be examined is badly decomposed, it is highly recommended to conduct a full-body radiographic study that might help to visualize otherwise hidden injuries and pathological findings.
• The estimation of age at death of unidentified victims also can be achieved through radiographic evaluation of epiphyseal closure.
• For certain cultures and religions, conventionally autopsy is stigmatized or even forbidden; various imaging techniques, like ultrasound, CT, and magnetic resonance imaging (MRI) may be allowed for conducting medicolegal investigations, respecting the sentiments of the victim’s next of kin.
• Complete-body examination by CT and MRI to obtain two-dimensional and three-dimensional documentation is used in vitropsy. 
• Radiologic necropsy includes a safe and easy examination of infected cadavers, minimizing the hazards to the practitioner.
• Age determination can also be done using x-rays.
• The precise location of a foreign body is better visualized in multiple radiographic planes, including anteroposterior and lateral ones.
• Skeletal age can be evaluated by the sequence of development and fusion of epiphysis of long bones and the development of centers of ossification in small bones. Other radiological developmental techniques include the careful estimation of bone-by-bone development of the hand.
• It helps in examining gunshot wounds. X-rays can be used to know the precise location of the bullet inside the body. It is recommended to do a whole-body examination as the bullet may even migrate. The wound track or the path of the bullet can be observed. Even if the bullet is not present, any small fragment can be located using radiography which will be sufficient for a ballistic identification.
• Radiographic evaluation of dental and skeletal maturation can be used to estimate the biological age of a living individual.
• Conventional radiography is considered an important component in the forensic assessment of sharp force injury to help identify and aid in recovery of broken knife blades and to help differentiate stab wounds from ballistic wounds.
• It can help in detecting intracranial and intraventricular bleeding.
• X-rays can be used for complex injury evaluation in abused victims or in persons where abuse is suspected.
• Multi-detector computed tomography scanning can be used for the depiction of the anatomic findings that are supportive for the diagnosis of drowning.
• Non-accidental injuries can be diagnosed using radiological technology. Techniques such as skeletal scintigraphy are highly sensitive in the detection of rib, spinal, and diaphyseal fractures and have a low sensitivity for cranial fractures. Radiological imaging plays a crucial role in evaluating craniospinal injury and the implementation of CT and MRI is advised in all cases of suspected non-accidental cranial injuries.
• Radiographic positive identification of unknown human remains is often attained by comparison of some markers present on the antemortem and postmortem plates.

Conclusion

An imaging technique using x-rays is a powerful tool in the field of forensic science. It reveals an in-depth amount of details before conducting an autopsy or surgery. It can help in the early recognition of hazardous objects like an exploding bullet that penetrated the body inactivated or any foreign material that has the potential to cause severe injury to the investigator or the practitioner if undetected before conducting an autopsy.

X-rays also prove to be the gold standard method for the identification of unknown deceased. To increase the impact of forensic imaging, training should be provided to forensic pathologists. As these x-ray plates can be stored easily, they can be used for re-evaluation and re-interpretation. The objective and non-invasive character of radiographic records make them a valuable tool for presenting evidence in court.