The acquisition interpretation and reporting of radiologic images for the purpose of medico-legal investigation. Forensic imaging is a relatively new addition to a forensic death investigation. However, radiological applications to forensic science old to the inception of radiology. First utilizing a radiograph as evidence in a court of law was in a North American court, in 1895.
Forensic Radiology is most well established in many countries like the United States, Switzerland, England, Australia, and Japan. In 2012 the international society of forensic radiology and imaging was established to strengthen and develop the field of forensic radiology and imaging worldwide.
Radiology tools available for postmortem imaging:
Most of the clinical imaging tools can be applied for forensic cases like:-
- Radiography (X-ray)
- Computed tomography
- Magnetic resonance imaging
- Picture archiving and communication system
In forensic science computed tomography known as Postmortem computed tomography is 3D X-ray technology.
Postmortem angiography is used as intravascular administration of contrast agent for evaluation of decedent vascular pathology.
Postmortem magnetic resonance imaging is a technique that utilizes magnetic fields and the magnetic properties of hydrogen nuclei in tissue to produce 3D images.
Skeletal survey series of radiographs to evaluate skeletal anatomy.
Contrast media and Image-Guided fluid and tissue collection are also very useful techniques to evaluate biopsy results.
Forensic Imaging Application:
There are many imaging applications in postmortem imaging including:
Firearm injuries: One of the most basic uses of radiography in forensic pathology is the acquisition of an x-ray for the purpose of foreign bodies. Bullets often reside distant from their entrance wound or trajectory can change depending on the tissue present on their path. By the use of Radiography, we can find out the number of bullets, the caliber of bullets, angle, and direction of fire. PMCT provides additional information concerning the extent of injuries, can depict in situ injuries to structures along the path of and the final destination of the bullet without altering the body. PMCT is a non-invasive method of rapidly acquiring and documenting potentially lethal injuries and in some cases, it can also determine projectile entry and exit sites as well as its path in the body. PMCT can reveal vascular structure which is difficult to dissect at autopsy.
Blunt Force Trauma: Radiographs can demonstrate fractures, dislocations, free air, and subcutaneous gas. PMCT can use with multiplanar images revealing soft tissue injuries and fluid collections. PMCT and MRI both can use to reveal life-threatening injuries.
Abuse: Certain fractures sustained during childhood are typically related to accidental trauma such as spiral fracture of the tibia in newly ambulating toddlers. Some injuries are non-accidental trauma that alternatively diagnoses are highly unlikely. Characteristic non-accidental injuries are multiple posterior rib fractures, long bone metaphyseal fractures, small bowel hematomas, and many brain injuries. It can also be evaluated by the Radiography technique. PMCT can be used to evaluate detailing fractures and associated soft tissue injuries. Both PMCT and PMMRI can be used to detect intracranial pathology.
Hanging: – PMCT is used for the recognition of typical hanging and strangulation findings. PMCT imaging findings associated with hanging include carotid artery injury tracheal and laryngeal Injury hyoid bone fracture and spinal cord injury.
Drowning: Detailed evaluation of the in situ lungs on X-ray and PMCT can reveal important focal lung findings but the ability to differentiate the etiology of these findings is limited. However, PMCT can reveal fluid in the paranasal sinuses and pulmonary bronchi which supports the presumptive diagnosis of drowning.
Decomposition: Postmortem changes begin at the death and progress over time. Decomposition rates depend on many factors related to the cause of death and environmental factors to which remains are subjected to. The most used technique used in decomposition is CT and X-ray to identify gas throughout all anatomic spaces as the result of putrefaction.
Identification: Identification of a body is the ultimate responsibility of the medical examiner. A radiologist can be part of the identification of the body. For identification, the examiner can collect fingerprints dental samples antemortem imaging examination results visual identification is also part of identification in most cases. Teeth can also important part of identification.
Challenges in Forensic Imaging
- Religious and Cultural objections: – Many cultures and religions object to the practice of conventional autopsy.
- Issues of cost and availability of tools.
- Expert trainers there are no current training standards set for forensic imagers.
About the Author
Vineeta Johri currently pursuing her Masters in Biotechnology at Rajasthan University, Jaipur, India.