Street Anatomy

Interlude: Medical Visual

Need a hand?

There is something anatomically incorrect about this color illustration…can you tell what it is?

Anatomie generale des viscères en situation, de grandeur et couleur naturelle, avec l’angeologie, et la nevrologie de chaque partie du corps humain (1752)

Artist: Jacques Fabian Gautier d’Agoty (1717-1785)
Surgeon: Jacques-Francois-Marie Duverney (1661-1748)

Trained as a printmaker, Gautier d’Agoty created his illustrations using a technique he helped pioneer, color mezzotinting. Mezzotinting involves making different color impressions using individual copperplates. He was the first to use colored mezzotinting in anatomical illustration.

Gautier d’Agoty worked with the surgeon Duverney to produce a series of life-sized plates. And although Duverney and several others helped him create the plates, d’Agoty boasts that he is the “demonstrator, artist and engraver all in one.” He was a very passionate and dedicated individual, however, his beautiful illustrations are noted more for their style than their usefulness to physicians. (The heart in the above illustration is not in the correct anatomical position)

Sarah Lowengard wrote a nicely detailed article on d’Agoty. Read it here.

Showing the success of treatment or progression of disease through digital image morphing: potential medical application

Warning: the following videos are graphic!

Click on these links to view the videos

Recluse spider bite

Healing frostbite

Digital image morphing of a bite from a brown recluse spider, progressing from a minor wound to an extensive necrosis of the skin and underlying soft tissues.

Successful healing of frostbite on the fingers.

You’ve probably seen digital image morphing before, either in commercials or in the movies. Hollywood has used digital image morphing for years now to turn humans into animals, humans into other humans, or to simulate aging. Now a paper by Keith Penska, Les Folio, and Rolf Bunger, entitled ‘Medical Applications of Digital Image Morphing’ in the Journal of Digital Imaging (2007), introduces digital image morphing to medicine.

Digital image morphing is a process by which one image transforms into another image through a series of generated intermediate steps. This is performed through a program that generates a smoothing algorithm that makes the final video seem to blend slowly from the initial image into the final one.

All you need to create an image morph is readily available software (just search for image morphing software on Google) and an average computer or laptop. To ensure a good image morph you do need to make sure images are of equal size and properly registered with each other. This will create a smooth transition. Also, make sure the backgrounds are the same. You can tell in the above videos that the images weren’t completely registered.

Digital image morphing has potential medical applications, especially for primary care physicians and their patients. It provides a quick and cost-effective way to show patients how their treatment has progressed over a period of time, or how their disease has progressed over time. And this doesn’t just apply to diseases or injuries on the surface of the skin. Image morphing can be performed with x-ray’s and even with MRI and CT scans. Plastic surgeons can use image morphing as a sort of digital portfolio to show before and after transitions. Image morphing provides a more dramatic effect than viewing two separate images of a before and after.

However, there are limitations. According to the journal article mentioned above, “ the smoothing process is synthetic and based on information from each of the images’ control points to reflect the blending of the images as the movie is created.” Basically this is saying the images in between the original images are not real, they are only an approximation. Obviously, the more images you have in the sequence, the more accurate the representation.

I’d like to hear what you think. Is this a good idea? Would doctors use this technology to educate their patients?

Virtual Autopsy: Visualizing the consequences of getting run over by a steamboat

In one of my last posts, I introduced the relatively new process of using MRI and CT scanning to perform virtual autopsies. Here I present a case where virtual autopsy was used to determine the cause of death of an unfortunate swimmer who was run over by a steamboat bucketwheel. Take a good look at fig 3 and you will instantly see the severity of the wounds inflicted on the body.

Case: A 53 year-old male swimmer was struck by the buckwheel of a steamboat in a local lake (fig 1). He suffered blunt trauma and sank. Divers found his body 5 days later at a depth of 18m.

fig 1

Virtual Autopsy: ‘The body was wrapped in two radiological artifact free body bags to preserve anonymity and to prevent contamination of the radiological equipment.’

First, a multi-slice computed tomography (MSCT) scan was performed on the body. This revealed comminuted fractures of the 8-10th thoracic vertebrae (fig 2). There were also fractures of the spinous processes of the 5, 8-11th thoracic vertebrae. The right shoulder was completely dislocated ventrally from the glenoid fossa (fig 3). Ouch. Fluid was found in the stomach, duodenum, trachea, and paranasal cavities. Both lungs were over inflated.

fig 2

fig 3

Next, an MRI was performed which revealed a complete rupture of the descending aorta at the level of the fractured 8-10th thoracic vertebrae (fig 4,5). A huge haematothorax was detected in the left thoracic cavity (fig 5 HT).

fig 4

fig 5

Generally, a complete rupture of the aorta will result in death due to fatal hemorrhaging at the site of the rupture.

Physical Autopsy: Confirmed all of the findings from the MSCT and MRI scans.

Cause of Death: A combination of fatal hemorrhage, caused by aortic rupture, and drowning.

The study concluced that “virtual autopsy using combined post-mortem MSCT and MRI is a useful tool for documentation, visualization and analysis of the findings of blunt force trauma and drowning with a large potential in forensic medicine.”

Source
Aghayev, E., Thali, M., Sonnenscein, M., Hurlimann, J., Jackowski, C., Kilchoer, T., & Dirnhofer, R. (2003) Fatal steamer accident; blunt force injuries and drowning in post-mortem MSCT and MRI. Forensic Science International. 152: 65-71.

Speared through the eye with a metal chair leg

[Article via Herald Sun]

MELBOURNE surgeons have miraculously saved a teenager who was speared through an eye with a metal chair leg.

Shafique el-Fahkri, 19, was admitted to Royal Melbourne Hospital with the chair leg embedded about 10cm through his head to his neck, where it had partially severed an artery.

He walked out of hospital on Friday, 19 days after being admitted, with no brain damage or loss of sight.

The horrific injury was sustained in a brawl in the city outside Metro nightclub in Bourke St. Fireman cut the chair away from Mr el-Fahkri’s head at the scene.

Doctors told the Northcote teen’s father, Moses el-Fahkri, they were astonished the youth had survived.

Read the rest of the article here

Tracing the Bullet Wound: Virtual Autopsy

CT and MRI scans are typically used for diagnostic purposes and there are numerous programs (e.g. Osirix) out there dedicated to computing the data from these scans and turning it into interactive 3D images. But, if CT and MRI scans can be used on the living, why not use them on the deceased? It just so happens that the winner of the 2006 Science and Engineering Visualization Challenge used a high-resolution CT scanner to generate 2D scans of a 2000 year old mummy that were used to create a 3D model of the mummy and its interior. From the scan researchers were able to reveal that the mummy contained the remains of a 4 or 5-year-old girl who had no signs of trauma or long-term disease. They suspected that she must have died unexpectedly, probably from an infectious disease.

Virtual autopsies are starting to be used as a precursor to the physical kind. The Pentagon has already used this technology on the remains of soldiers who died in Iraq and Afghanistan to determine the effectiveness of helmets and body armor for protection. Forensic investigators in Sweden and Switzerland have performed numerous virtual autopsies on murder victims and are working to perfect the technique. Medical examiners from all over the world, including the U.S. have taken interest.

The benefit of using CT and MRI to create full-body scans of the deceased is that it is non-invasive. Full-body 3D images generated from the scans can be easily be manipulated by zooming in, cropping, and rotating in any direction, something not possible by physical autopsy. In murder victims, bullet paths can instantly be found and the extent of knife wounds easily visualized. This would normally take hours through physical autopsy.

Another benefit of using virtual autopsy, or Virtopsy, is the permanency of the data. Physical autopsies need to be performed soon after death to get an accurate evaluation of the cause of death. With virtual autopsy scans can be performed quickly and the data would be there to be used weeks, months, or even years later. And the data can provide powerful evidence in the courtroom without using graphic images from the real body.

Knife wound to the heart: autopsy and MRI finding

Virtual autopsy can also be used in cultures where physical autopsy is not permitted by custom or religion. Since virtual autopsy does not mutilate the body in any way, the body can be preserved in its natural state.

What about cost? Powerful imaging equipment can be extremely costly, but while traditional autopsies cost an average of $4,000 each, virtual autopsies cost around $1,000 each. This means that virtual autopsies can actually cut the cost of autopsies and ease the financial burden on hospitals and families.

Researchers in this area predict that within the next 10 to 20 years, physical autopsies will be replaced by the virtual autopsy.

The pace at which medical imaging is advancing is incredible. The impact of this type of medical imaging on medical illustration will result in the most accurate illustrations and animations ever created. Because of this, future generations are going to have the benefit of having the most complete understanding of the human body.

Sources and further reading

Virtual autopsies offer help in divining death.

Autopsies, no scalpel required.

Medical experts gather in Australia to eye 3D future of post-mortems.

Virtual autopsy may be next innovation in forensic field.

Images via RSNA