Virtopsy: A New Era in Forensic Medico-Legal Autopsies

Abstract

In the field of forensic science, autopsy that is postmortem examination involves a thorough corpse examination done in order to determine the cause and manner of the death by invasive method. With the advancement of technology a new term: “Virtopsy” meaning virtual autopsy employs the application of imaging techniques namely computed tomography (CT) and magnetic resonance imaging (MRI) has proven its advantages in the forensic field. It involves the scanning of dead bodies in a non-invasive manner. It a great alternative to the traditional autopsy as it provides wide-range and systemic examination of the whole body in a less time duration, benefits in diagnosis as well as renders respect to religious sentiments. Method is more specific, sensitive, & precise and accurately reflect soft tissue injuries, organ damage, wound extent, fractures which provides instinctive and powerful court evidence for forensic identification. The chapter will be describing the importance of “Virtopsy” in the field of forensic science and its future scope in forensic crime investigations.

1. Introduction

Traditional autopsy is one of the classical method utilized for the investigation and identification of cause & manner of death. This scientific examination procedure of dead bodies involves complete exposure of the body surface and cavities in order to record the findings which will prove to be useful in establishing the facts pertaining to the circumstances leading to the death of an individual and helping the law enforcement. At the same time gaining consent for the forensic autopsy involves relatives’ sentiment or religious belief. Furthermore, some religious and cultural aspects oppose for the autopsy procedure such as Judaism, does not permit the same [1, 2, 3]. All these aspects direct the need of a ameliorate autopsy method which overcomes these deterrents and equally prove to be as significant as the traditional method of autopsy. “Virtual Autopsy” or Virtopsy is the new method which is one step towards these advance technology in the field of forensic science.

Virtopsy is a modern method which is scalpel free techniques of performing autopsy using modern imaging and measuring technology [4]. It was coined by Richard Dirnhofer, the former Director of Forensic Medicine, University of Berne’s Institute of Forensic Medicine, Switzerland [5]. The virtopsy procedure includes a complete Three-dimensional (3D) surface scanning 3D/computer-aided design photogrammetry, Multi-slice computed tomography (MSCT), Magnetic resonance imaging (MRI) and MRI spectroscopy [6]. It provides a complete inside and outside view of the body in three dimensional way. The vital information such as position and dimensions of injuries or severity of injuries or other pathological conditions can be gather in a digitalize manner, thus facilitating effective assessment of body’s condition. It’s a promising tool encompassing high scanning and radiographic technology possessing the power and resolution of modern computing, which prove to be useful to investigators, forensic pathologists and doctors [7].

2. Application of Virtopsy in forensic sciences

Virtopsy has shown its wide range of applications in the field of forensic with respect to various aspects such as thanatological investigations, firearms injury, age estimation, fracture estimation, putrefied body identifications, forensic odontology, mass disaster cases, anthropological examinations, drowning cases, skin lesion analyses, charred bodies identification etc.

In drowning cases, determination of whether the drowning is ante-mortem or postmortem and what is the actual cause of death is very significant for the forensic experts. The computed tomography (CT) data reveling evidences about the volume of liquid present in lungs, density and size of the lungs thus helping in identifying the actual cause of death. Levy et al., in 2007 [8] performed the post-mortem computed tomography (PMCT) in drowning cases and first reported the imaging findings. They marked the PMCT feature of the presence of foam-covered airway fluid or high-attenuation deposit in the airways of cadavers. Also the fluid presence was noticed in the para-nasal cavity, mastoid air cell fluid, gastric distends and contents, proving the facts of death due to drowning [9] in 2010 reported the applicability of PMCT in determination of cause of death in case of a middle aged male who died after falling in a sewage pool. PMCT imaging showed the presence of blood accumulation in the right external auditory canal, right humerus fracture, subarachnoid space possessing small hemorrhages, left temporal lobe showing brain contusion injuries, the occipital scalp showed occurrence of scratch and bruise injuries on the right side. All these injuries in combination may have cause unconscious leading to coma, thus making the individual unable to rescue himself from pool. Other findings such as presence of fluid in the air passage, paranasal sinuses, gastric and duodenal expansion also indicates that the victim was continuously breathing and swallowing even after falling into the water. Further the proof that water has entered into the respiratory and circulatory systems was established from the PMCT findings showing opacity in both the lungs (Figure 1) [10]. Jian et al. performed a study involving drowned rabbit model. They compared these animal models of hemorrhagic shock and mechanical asphyxia. The CT values indicated that the lungs volumes were significantly higher (P < 0.05) thus signifying that the virtopsy characteristics can reflect the important features in case of antemortem drowning [9, 11].

Figure 1.

PMCT revealed the bullet's entrance (white arrow), the skull fracture caused by the bullet (white circle), and the bullet and the exit (dotted arrow).

In cases of firearms injury, the determination of permanent damage caused by the bullet, entry & exit of bullet, diversion of bullet by anatomical structure can be studied in detailed by the use of Multislice spiral CT. Gibb [12] demonstrated the use of CT in real cases and animal models and identified the several characteristics of injuries caused by different types of firearms and ammunition (Figure 2). Harcke et al. [13] utilized CT scans of less intensity for 3D projection and 3D volume reconstruction on the complete body of cadavers possessing gunshot injuries. They examined the bone damaged, projectile trajectory as well as bone fragments in the body. The technology proved to be very significant at the level of identifying the perforation and penetration caused by firearms. Further, Karger et al. [14] studied tissue disruption in case of gunshot to the head by using MRI and PMCT. They observed that the permanent tract of tissue damage was very well defined as well as the fragments of the bone were easily located inside, which could not have been identified in case of normal traditional autopsy. In china, a police officer committed suicide due to depression whose PMCT was performed. The data clearly inferred the bullet entrance & exit hole, skull fracture, trajectory of bullet and other injuries along with the manner of death decipherment as shown in Figure 3.

Figure 2.

(a) SSD reconstruct revealed the fracture of right temporal bone (black arrow). (b) Fluid in the paranasal sinuses (white arrows), and dense sediment (black arrows). (c) Fluid in the throat (white arrow). (d) and (e) Fluid in the trachea (white arrows). (f) The diffuse ground-glass opacities in both lungs.

Figure 3.

(a) PMCTA results showed a leakage of the contrast agent from the C3 segment of the left internal carotid artery (white arrow) into the adjacent left sphenoidsinus (white circle), suggesting an aneurysm. (b)An aneurysm inside the left sphenoid sinus (black arrow) was confirmed by autopsy, consistent to the PMCTA results.

Virtopsy technology has shown its wide application in the field of forensic odontology. Human identification and age estimation can be achieved via dentition structure as it comprehends multiple teeth identifiers [15]. Dental identification encompasses the comparison between ante-mortem and post mortem evidence, analysis of dentition profiles of PM victim and dental DNA examination [16]. In certain cases the access to the dentition or oral cavity postmortem data is hindered (e.g. rigor mortis condition) the use of virtopsy can prove to be accurate and rapid way to shelter the information [17]. Oesterhelweg et al. [18] described a case where a foreign material (food bolus) got struck in respiratory tract. In case of traditional autopsy the depth of these material would not have been determined but the use of CT and MRI overcome these facts. Personal identification was achieved by superimposition and comparing the data of ante mortem orthopantomo grams and postmortem reconstructed panoramic imaging of cranial CT scans [19, 20]. Dentistry helps in the age estimation in case of charred bodies where the use of CT scans have proven its application in a well-defined manner as described by Dedouit et al. [21]. Personal identification was also achieved in cases of the Australian bushfire victims through the CT scans based on age estimation techniques [22, 23, 24]. Researchers have demonstrated the use of Virtual Autopsy in case of fire mass disaster by simulating the complete scenario. Jackowski et al. [25] utilized different restoration materials namely composites, ceramics and temporary fillings under high temperature and the CT scans of the same were studied [26].

Death occurring due to cerebral hemorrhage are observed very frequently in forensic investigation. In 2017, Qian et al. [27] studied a case where the individual died due to rupture of cerebrovascular distortion. The PMCT scan of brain’s right frontal region indicated massive hemorrhage ranging up to the ventricular system. Histological examination also established the facts of PMCT angiography that the death was caused by an arteriovenous distortion (Figure 4).

Figure 4.

(a) Massive hemorrhage in the brain's right frontal region, extending into the ventricular system (white arrow); (b)a mass of irregular, tortuous vessels in areas of hemorrhage in the right frontal lobe of the brain (white circle); a contrast agent was injected into the basilar artery ( white arrow); (c) Lumps of abnormal blood vessels within the region of hematoma (star); small blood vessels were dilated and tortuous, and the thickness of the vessel wall varied (black arrow).

In 2017, Shao et al. [28] executed PMCT angiography on a deceased who suffered a head injury during a traffic accident. The deceases had fractures of frontal and sphenoid bones-left. The PMCT angiography showed rupturing of internal carotid artery aneurysm. Consequently, the location of the injury spotted by the virtopsy, autopsy and histo-pathological examination confirmed that the sinusoidal vascular injury was a pseudo aneurysm initiated because of the traffic accident. The application of virtopsy can prove to be applicable in cases where the real cause of the damage in not known by the investigator (Figure 5).

Figure 5.

Left: computed tomography three‑dimensional reconstruction shows fractures in right ribs 2–4 (white circles); Right: computed tomography three‑dimensional reconstruction shows scattered bullets (blue‑green).

3. Reconstruction

Michael J. Thali et al., [29] established the use of 3D data centered on geometric methodology. It involves the use of radiological CT/MRI, scanning photogrammetry, and optical surface which examine the topography and internal injuries in case of living as well as dead bodies in non-invasive and non-destructive manner. These results can prove too significant for the reconstruction in crime scene cases. The use of the data fusing and animation techniques various reconstructive questions can be answered with respect to the patterned injuries and their link with the suspect or injury causing instrument. The documentation in forensic aspects was limited to the traditional 2D photography, radiographs, sketches and witness description. This recent development in 3D imaging has described a new approach in the forensic examination and reconstruction. Michael J. Thali et al. applied these technology in automobile accident reconstruction cases. They created 3D data of the injuries and link it to the animation created data with respect to the body injuries and vehicular damage. The detailed measurements and analysis of the damages caused to the vehicle not only allowed to determine the impact points but also helped in force determination and vehicle speed. 3D real data documentation opens up a new horizon in the examination of forensic evidences, reconstruction and thus creating an animation of the incidences pertaining to case investigation as shown in Figures 6 and 7. In 2007, Buck et al. [30] generated the 3D models of human injuries and vehicles during the traffic accident by the application of high-resolution surface scanning and multi slice CT/MRI scanning. The scanning provided information useful in judging the positions of vehicles. Various authors showed the use of 3D scanning in vehicular accidents with respect to the injuries examination, cause of death and vehicle damage. They concluded that a combination of PMCT and autopsy can prove to be the best way for the determination of cause and manner of the death in traffic accidents [31, 32, 33, 34, 35].

Figure 6.

3D geometric data for forensic analysis and reconstructive animation are possible. Investigative opinions can be analyzed, helping to develop an expert opinion.

Figure 7.

Implementation of the skeletal and joint information into the data set of the car allows for individual and correct (real data based) simulation of movements of the body.

4. Advantages

The most important advantage of the technique is it is non-destructive method of examination which is scalpel free mode. It is an ethical fruition of the technology which make the body examination more acceptable without hurting the sentiments of the family as well as maintains the body architecture. It is less time consuming and the data generated in a manner of images is easily transferable, can be reused for future studies also. It proves to be most effective way of examination of injuries and establishing the relationship with the probable weapon used for the commission of crime. The 3D scanning also adds in the weightage of the forensic report and make the work easy for the experts in describing the reconstructions or animations of the case investigations. The examination can be performed with ease without causing any damage to the authenticity in a non-destructive manner in both living and non-living individuals. Forensic documentation can be done via storing the data in images format obtained from photogrammetric and 3D optical scanning. Virtual autopsy also reduces the chances of the infections, radionuclide, toxic substances or other biohazards. The imaging system has come out to be a steadfast tool in modern forensic examination with various aspects of its application in different fields.

5. Disadvantages

Although the technique has wide advantages but does possess certain flaws into it. Certain pathological conditions such as the level of infection into the cadaver, changes in physical features namely color, spoor and small tissue damages cannot be defined or may get miss. The system does not have database which can prove useful for the comparison purpose. It becomes difficult to differentiate between ante-mortem and post mortem injuries. Accuracy can become questionable if the data merging happens from multiple technology also can create a complete dependency on the imagery system.

Conflict of interest

The authors declare no conflict of interest.