29.1: Scope of Forensic Radiology

• Forensic radiology is an area of expertise in medical imaging utilizing radiological techniques to aid physicians, pathologists, and medicolegal experts in the matters associated with the law.

• It is a visible and permanent record. Because it is permanent it is available for reinterpretation and revaluation at any given time.

• Identification data such as name, place, and time of exposure are extremely significant and should be exposed as much as possible on the radiograph.

• Radiologic data are specialized in character, and so they require the skilled interpretation of a radiologist while giving evidence.

• Radiologic data should be presented in scientific terminology first and then the clarification done with non-medical terms.

Identification

• X-ray examination of the pelvis, skull, frontal bones, and mandible may give definitive information about sex.

• The pubic bone adjacent to the pubic symphysis in the pelvis will be rectangular in females and triangulate in males.

• Male vertebral bodies tend to be larger. The long bones of the females are thinner and smoother. Females have smaller supraorbital ridges, mastoid processes, and mandibular condyles

• The radiological study of costal-calcification patterns is a recent advance in sex determination.

• Orthophantomogram (OPG): An ideal evidence in determining age depending on tooth eruption.

  • Measuring diaphyseal length and demonstrating ossification centers can estimate fetal length and age.

  • The appearance of ossification centers and their fusion is a well-established and accepted method of age determination approved by the court.

• In infancy and childhood, the ossification centers present in the wrist radiograph are helpful.

• In adolescents, demonstration of the epiphysial union at the wrist, the base of the skull, etc. helps to evaluate the age.

• An X-ray can demonstrate calcification of laryngeal and costal cartilages in 5th decade of life.

• Radiology of the wrist can also help in the determination of age, from the internal structure of the cancellous bone and cortical thickness of the head of the humerus.

• Radiographic identification by studying frontal sinuses has been found very useful in mutilated bodies or burnt bodies.

• An X-ray can disclose very specific morphological patterns of the individual:

  • dental restorations,

  • information on root canal treatment,

  • buried root tips and jaw bone pattern,

  • dental peculiarities such as gaps between teeth, a broken tooth, gold crowns, etc.

  • may enable identifications easy when it matches with the antemortem dental radiographs of the deceased are well preserved by the dental practitioner.

Radiology and Trauma

• Radiologic investigations often make significant contributions to the analysis of diagnosing trauma.

• Bones may be injured, with fractures and hematoma can be detected.

• Joints may be injured with resultant subluxation or dislocation. Loose bodies or air may appear in these cases in the joint.

• Neurotrophic joint abnormalities due to diabetes or Tabes dorsalis can be detected radiologically and help in establishing identity.

• Soft-tissue trauma may be manifested as swelling, gas within the soft tissue, and at a later date by calcification. Lacerations, denudations, and defects may be detected on X-ray.

• The solid and hollow viscera, which are injured, can be detected on X-ray. Abnormal air accumulation in the abdomen indicates a visceral injury.

  • The presence of a pneumothorax demonstrated on an X-ray chest indicates a lung injury.

• Mutilated remains, especially those from mass disasters, should be X-rayed, for example in fire victims where external damage makes dissection difficult.

  • Where bombs or explosive devices are involved, it leads to the identification of any part of the mechanism that may be embedded in the soft tissue.

Radiology and Battered Child

• A radiographic examination of the entire skeleton before the autopsy is required whenever child abuse is suspected. CT scan of the head is equally helpful in visualizing skull fractures among the victims of child abuse fatalities.

• Where the radiographic findings are not very obvious, another X-ray after removing the organs is helpful. Multiple skeletal injuries in different stages of healing are commonly encountered.

  • They include the separation of the metaphases of long bones due to rough handling and violent shaking.

  • This is observed more often in children under one year of age.

  • Destruction of the adjacent end of the bone can usually be seen in about two weeks if they are not immobilized after the injury.

  • Injuries of the metaphases are a typical skeletal manifestation of child abuse.

• Another common injury that is seen with child abuse is a fracture of the posterior ribs, which may be visualized on the radiograph.

Radiology and Firearm Injuries

• The bullet track also can be identified if the bullet is jacketed when it leaves a trail of metallic particles from the jacket.

• X-ray is sometimes used to measure the caliber of the bullet, in a living person where surgical removal of the bullet is not indicated.

• The use of X-ray is of value in the case of skeletonized bodies where a perforating fracture is present in the bone.

• X-ray may reveal a bullet track through the bone by the presence of metal fragments along the track.

• Because the use of radiology in modern forensic medicine has been, until today, mostly restricted to conventional X-rays, which reduces a 3D body to a 2D projection, a detailed 3D documentation of a gunshot’s wound ballistic effects was not possible.

• Multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) are technologies used for the documentation and analysis of gunshot wounds.

• CT scans and MRI of the cerebral parenchyma revealed lanes of opaque bone and missile fragments along the course of the missile, which allowed recognition of the missile track in 3D reconstruction.

• With the spiral CT and MRI examinations and the subsequent 2D multi-planar reformation (MPR) and 3D shaded surface display (SSD) reconstruction, the entire gunshot-created complex skull fractures and brain injuries could be documented in complete and graphic detail.

Radiology and Asphyxial Death

• Radiography of the neck may be carried out before any dissection to determine the state of the cervical spine and the laryngeal cartilages.

• An X-ray of the cervical spine in situ both antero-posterior and lateral may reveal a number of the transverse process of the atlas vertebrae which may be responsible for vertebral artery injury, which passes through it.

• A radiograph after dissection of the cervical spine reveals the fracture better.

Radiography and Smuggling

• Radiologic evaluation may be useful in detection and confirmation of smuggling narcotics, which may be enclosed in plastic containers and swallowed.

• Radiologic visualization is sometimes helpful. Small precious objects as pearls, diamonds and gold may be swallowed in an effort to smuggle them. Radiologic exploration might locate them.

29.2: Uses of Forensic Radiology

1. Suspicious death or murder

   • Radiographic techniques can assist the pathologist in determining the potential cause of death and may alert them to a previously unsuspected suspicious death.

   • Autopsy technique may need alteration, given the prior knowledge of specific radiographic findings.

2. Analysis of adverse medical events

   • During the course of hospital admission or medical care, adverse events may occur.

   • Radiographic imaging is an integral part of the medical process and provides a permanent record of the patient’s condition.

   • Specialist review of these images in the light of autopsy findings and clinical audit can aid in the prevention of future mishap.

3. Legal matters

   • Following injury or assault, radiological imaging is commonly obtained by medical practitioners.

   • Expert interpretation of these images may provide useful evidence in criminal and civil jurisdictions.

4. Child abuse

   • Radiological techniques are mandatory in providing evidence of both acute and chronic injury.

   • Some of the findings are very specific for abuse and crucial for conviction of culprits.

5. Drug trafficking

   • Increasingly sophisticated methods are used by drug traffickers to avoid detection.

   • This includes the deliberate ingestion or cavity insertion of drugs wrapped in protective materials. These packets are readily identified on CT scans and can assist law enforcement agencies in screening suspected individuals.

6. Body identification

   • Along with dental and DNA analysis, radiographic images be used in the identification of unknown victims.

   • This requires the securing of premortem examinations.

7. Disease identification

   • During the course of an autopsy there may be findings that can have the consequence of the deceased family.

   • In order to confirm such a pathological suspicion, radiographic procedures can provide confirmatory evidence and as such lead to the deceased’s family being offered genetic screening.

8. Donor bank analysis

   • All body parts donated for use as grafts, in particular bone, must be carefully screened prior to use in order to avoid the insertion of “diseased” material into a recipient.

   • This can be accurately performed “non-destructively” utilizing radiographic techniques.