Virtopsy is a non-invasive virtual autopsy technique that uses medical imaging like 3D surface scanning, CT scanning, MRI, radiography and angiography to examine a corpse without dissection. It was developed as an alternative to traditional autopsy to avoid invasiveness. Virtopsy captures detailed internal images of tissues and bones within 10 minutes using these scanning techniques and reconstruction on computers. It allows for second opinions even after cremation since findings are in a digital format. The procedure involves placing a body in a scanning machine to generate thousands of cross-sectional images which are then reconstructed into a virtual 3D image of the interior. Virtopsy is being used to determine causes of death, identity, age and aid investigations

1. VIRTOPSYV I R T U A L A U T O P S Y
BY
LOKESHWARI.V(15MCA14)
ASHA.V(15MCA03)

2. INTRODUCTION
• Virtopsy is a term that came from virtual autopsy.
• It was developed by Richard Dirnhofer, former director of Forensic Medicine, Berne,
Switzerland.
• Originated in mid 1990’s.
• It is a scalpel free procedure to carry out autopsy using medical imaging techniques.

3. AUTOPSY V/S VIRTOPSY
AUTOPSY
• Thorough examination of corpse
through dissection.
• Types of autopsy:
– Medico-legal Autopsy
– Clinical Autopsy
– Anatomical Autopsy
• Second opinion is not possible as it
would have damaged some of the
parts.
VIRTOPSY
• Alternate method for much safer
procedure as it is a blood less
procedure.
• Techniques used are:
– Robot guided 3D surface scanning
– Multi-Slice Computed
Tomography(MSCT)
– Post mortem Angiography
• The findings of virtopsy are in digital
format.
• Second opinion of any expert is possible
even if the body is cremated

4. TECHNIQUES IN VIRTOPSY
• 3D Surface Scan
• photogrammetry
• Multi-Slice Computed Tomography [MSCT]
• Magnetic Resonance Imaging [MRI]
• Radiography
• Angiography

5. 3D SURFACE SCAN
• A 3D surface scan takes pictures of the patient to provide a visual record of the
condition.
• The images are taken in a booth that includes several cameras.
• These cameras are positioned to obtain photographs from multiple angles of the
anatomy under consideration.
• This may involve the face,the entire head ,the torso or the whole body.
• The images are then combined to create a photorealistic 3-D static image of the
patient.

6. PHOTOGRAMMETRY
• The photographic projection in a camera can be described mathematically as central
projection
of the object onto the plane.
• Every single object is mapped in an image point ,which is the intersection point of the
projection beam and the image plane.

7. MULTI-SLICE COMPUTED TOMOGRAPHY
[MSCT]
• The full-body multislice computed tomography (MSCT) was performed for study of
bone lesions and cause of death.
• MSCT was superior to autopsy in diagnosis of traumatic bone lesions and also
revealed dental anomalies and signs of drowning.

8. MAGNETIC RESONANCE IMAGING [MRI]
• Magnetic resonance imaging (MRI) is another non-ionising technique available for
forensic analysis.
• It is much less extensive compared to ionising approaches.
• It is more frequently applied in cases involving living individuals.
• It is primarily used in relation to the estimation of skeletal age, and for the specific
purpose of the determination of legal culpability.

9. RADIOGRAPHY• Radiography is an imaging technique using X-rays to view the internal structure of an
object.
• To create the image, a beam of X-rays, a form of electromagnetic radiation, is
produced by an X-ray generator and is projected toward the object.
• The X-rays that pass through the object are captured behind the object by
a detector (either photographic film or a digital detector).
• A certain amount of X-ray is absorbed by the object, dependent on its density and
composition.

10. ANGIOGRAPHY
• Angiography is the use of fluoroscopy to view the cardiovascular system.
• An iodine-based contrast is injected into the bloodstream and watched as it travels
around.
• Since liquid blood and the vessels are not very dense, a contrast with high density (like
the large iodine atoms) is used to view the vessels under X-ray.
• Angiography is used to find aneurysms, leaks, blockages (thromboses), new vessel
growth, and placement of catheters and stents.
Angiogram showing a transverse projection of
the vertebro basilar and posterior cerebral
circulation.

14. PROCEDURE OF VIRTOPSY
• It uses combination of techniques like 3D surface scan, Photogrammetry & MRI scan.
• It uses a robotic machine called “VIRTIBOT”.
• Small disks along the exterior of the body is placed. Using Virtibot 3D color model of
the corpse is created. The robot moves over the body creating 3D image for about 10s.
• Then the body is placed inside a blue bag which prevents from contamination and
helps x-rays to pass easily is scanned using MRI, CT MRS equipment. The body
undergoes CT scan that finishes in 20s and acquires up to 25,000 images. Each image
is cut through or slice of the body.
• Within 10 minutes the detailed image of tissue, bone are reconstructed using powerful
desktop computers.
• With the click of mouse, the pathologist can peel through the layers of virtual skin and
muscle.

15. IMPLEMENTATION
• The reconstruction of 2-D images can be performed with a Filtered Back-Projection (FBP)
type reconstruction and an iterative Ordered Subset Convex (OSC) maximum-likelihood
method
• A special software is used to simulate transmission tomography scans with different signal-
to-noise ratios (SNR)
• The noise and modulation transfer function is calculated for FBP and OSC reconstruction at
several positions, distributed over the field-of-view (FOV)
• The OSC method achieves a lower level of noise compared with FBP at the same resolution
• The reconstruction with OSC can save a factor of up to nine of x-ray dose compared with
FBP in the investigated range of noise levels
• The OSC algorithm was modified so it calculates the normalization term before the iterative
process to save computational cost. The modified version requires only one back projection
per iteration as compared to two required for the original OSC

16. • The OSC algorithm updates all estimates of the attenuation coefficients µn
s+1 (k)
– Yi represents the measured transmission counts in bin i
– di represents the blank scan counts in bin i
– lij is the length of projection line i through voxel j
– S(s) contains the projections in subset s

17. • Transmission images were reconstructed with the OSC algorithm using 50, 125 and
250 subsets
• They were compared with images reconstructed with the standard convex algorithm
serving as the ‘gold standard’
• The N subsets were chosen such that the angles θ between the n projections in each
subset were equal (θ = 2π/n)
• The order in which the subsets were used during each iteration of OSC was-
Δθ ∈ {0, 1.2π/N.n, 2.2π/N.n, . . . , (N − 1).2π/N.n} between s+1 & s
• Angular difference Δθ was as close as possible to the centre of the largest angular
gap of projection angles that had not yet been processed in the current OSC iteration
(Δθ as close as possible to π/n)

18. USES OF VIRTOPSY
• Time of death.
• Identification of individuals.
• Determination of age and sex of individual.
• Death due to burns.
• Manual strangulation or hanging.
• Road traffic accidents.

19. CONCLUSION
Autopsy has its merits but virtopsy has futuristic advancements that provide
privacy to deceased family. At the present virtopsy cannot replace conventional autopsy
since it is a new development in the field of investigation of death.

20. REFERENCES
• http://www.sciencedirect.com/science/article/pii/S2090536X16300211
• http://medind.nic.in/jal/t14/i2/jalt14i2p195.pdf
• https://www.wired.com/2012/10/virtual-autopsy-2/
• http://journal.opus12.org/o12-ojs/ojs-2.1.1/index.php/o12sci/article/viewFile/249/75
• https://link.springer.com/chapter/10.1007%2F978-90-481-8990-8_9

21. THANK YOU