Abstract: Medical visual representations, including computer-generated simulations, are placed pivotally at the juncture of science, medicine, visual representations and society. Our own research focuses on elucidating the role of complex fluid mechanical forces in cardiovascular disease. Blood flow visualization is a combination of medical imaging and computer simulation to augment the clinician’s ability to examine and study. Due to unprecedented abilities of explorations into the body and broad cultural implications, our research requires finer visual models. Our own results are based on established stylistic conventions, which is why we seek a fresh approach through crosspollination, through direct collaborations with artists, as well as incorporating advances in aesthetic and cognitive visualization research as part of a multidisciplinary initiative bringing together ideas and people from diverse fields and with various backgrounds.
Introduction: In the following paper we briefly summarise the development of medical images and imaging techniques as they pertain to elucidating the role of fluid mechanical forces. We highlight the connection between representation of scientific data and the artistic trends of the time as well as the role played by the artist in conceptualizing physiological phenomena. Subsequently we discuss the creation of iconic anatomical images that have survived their originary time and “seeped” outside the scientific realm.
The research carried on in our laboratory is a multi-step process through which, from the reality of the human body through the generation of a mathematical model that is than translated into a visual representation, a refined virtual image — easily understandable and used by clinicians — is generated. Our research generates virtual representations of blood flow that can serve two purposes: a) that of a model of a phenomenon or disease and b) that of a model for experimentation (and thus constitutes a non-invasive way of determining the best treatment option).
Technology is as ubiquitous and versatile a presence in the medical world as in society at large, allowing the real and the virtual to merge and blend almost seamlessly. We will discuss aspects of this merging encountered in our research and its visual representation, as well as the changes this brings to our perception of medical imaging.
The main objective of the paper, however, remains focused on the major steps forward as well as the limitations and challenges encountered in the visual rendering of phenomena and concepts. These suggest an imperative need for collaborations and transdisciplinary efforts. The importance of such cooperation stands not in terms of aesthetic qualities of images or the effectiveness of medical visualizations as much as in facilitating better understanding at the conceptual level and in opening new venues of scientific investigation.
Thus, the paper will open with a brief look at the evolution of medical images and imaging as pertains to elucidating the role of fluid mechanical forces, and will then make a connection with the representation of scientific data (the visual translation into a clinical vocabulary) by way of direct examples from our research. It will conclude with a reflection on the role played by the artist in the creation of iconic anatomical or medical images as well as the conceptualizing of physiological phenomena.
A Historical Overview of Medical Imaging
Over the centuries, creating medical images of the human body has been an area of expertise for artists. The medical illustrations have provided an educational role for organising and transmitting information gathered by anatomists and clinicians, presented within the frame of the visual vocabulary of the time. Consequently the resulting images can be viewed as learning aids and also as reflections of their contemporaneous culture. Following the evolution of the role of non-artistic images over the millennia, James Elkins noted that they changed aesthetically without their scope, usage and conventions being fundamentally altered (Elkins, 1999). The same can be said about current medical images in particular; from an aesthetic or technical perspective, they are significantly changed from the ones found in medical atlases centuries ago, but the challenges faced by the parties involved in generating, using and distributing them are almost indistinguishable.
In terms of the historical evolution of medical image and imaging, one can argue the existence of two major turning points: one being the 1543 publication of Vesalius’ De Humanis Corporis Fabrica and the other the 1896 discovery of X-rays by Dr. Wilhelm Roentgen. The first confirmed and consolidated the lead of the artist in the representation (and possibly the use of these representations) of the hidden human body in epistemological terms; the second brought technology to the forefront of discovery and research, while opening new paths to representation.
Medical atlas illustrations were deeply influenced by contemporary cultural and artistic trends. This is exemplified by Vesalius’ outstanding atlas, whose now-well-known illustrations were the work of Jan van Calcar, a student of Titian’s.1 The trend continued well into the 19th century as exemplified by the famous Grey’s Anatomy, set apart from other contemporaneous atlases by its anatomically accurate, aesthetically appealing and clearly labeled illustrations. A less known fact, relevant for the purpose of this paper, is that Henry Vandyke Carter, himself a surgeon and illustrator of the atlas, had been trained by his drawing-teacher father, Henry Barlow Carter.
Technological advancements of the times are equally robust contributors, and they are obvious in the quality of the illustrations, such as detail and nuance in rendering the anatomical structure. An interesting instance highlighting the intertwining of artistic depiction and technological development in medical illustrations is that the engraver of Govert Bidloo’s 1685 atlas, Anatomia Humani Corporis, was Abraham Blotling, the inventor of the rocker tool used in mezzotinting.
As the technology shifted from drawings to woodcuts to copper plates to photographs, the gaze of the anatomist followed suit and the ability to envision the obscured parts of the body was enhanced. It was, however, the (incidentally accidental) discovery of X-rays that produced a major turning point in the direct imaging — but also the artistic depiction — of the body. The penetrating view of X-rays into the living human body opened new windows and new venues as the technology itself, as well as the imagery that is associated with it, came to change forever the way the world is perceived. It is not only the scientific field that was altered in both its ways of questioning as well as of the questions asked, but also society at large and, in particular, the artistic community. What sets the post-X-ray period apart, in our view, is the awareness of the artist regarding the imagery and procedures of a technology not intended to promote artistic creation. This arguably lead to a rapprochement between the arts and sciences, as it was the instant when practitioners of each began to use the same technology and, later on, techniques. Since the Age of Enlightenment, the two have been following separate trajectories, however the last century’s overture towards technology-based communication of images, and the wide interest in and relatively easy access to these technologies enabled and stimulated cross-pollination (Reichle, 2009). X-rays and the visual access they allowed into the living body stimulated the visual innovations of artists such as Picasso, Braque, Duchamp and Kupka. Body representations acquired the mechanical extension of the “normalized” body structures by artists such as Hoerle and Kahlo.
Technological developments in general also supplied an element of metaphor and analogy in the medical narrative, facilitating the description of the functioning of the body (e.g., Kendall (1919) or Kahn (1926)) and later that of the cell (e.g., Myers, 2008) as a sort of factory procedure.
Visualization and Modeling Techniques for the Study of Blood Flow
The study of blood flow closely followed the evolution of medical research: from the rudimentary yet insightful experiments designed by Leonardo da Vinci, to the description and representation of the vascular tree of Andreas Vesalius and all the way to the Gray’s Anatomy illustrations that brought together anatomy and physiology and opened the door to the in-depth study of blood flow and its visual representations (Fig 1).
Fig 1 - Attempts made over the centuries to represent circulation within the human body; the examples are reflecting the change in visual representation going from the shape and location of blood vessels in the human body, to trying to understand the dynamics of blood flow and the causes of any alteration in the normal pattern: (A) 15th century map of vessels; (B) 16th century blood flow representation; (C) 19th century atlas illustration of veins and arteries (colour-coding); (D) 20th century representation of blood vessels, including the typical locations of atherosclerotic plaque (DeBakey et al, 1985)
The criteria for selecting the above figures are the commonalities with current days medical illustrations and representations: the mapping aspect, the colour conventions and the attempt to connect flow disturbances to vessel geometry. The need for mapping persists, but as the territory to be mapped changes, new and diverse challenges are faced. Current mapping of blood velocities as well as wall shear stress will be shown later (Fig. 6). The colour conventions have stayed virtually unchallenged and unchanged and have been adopted into the repertoire of modern medical imaging, such as Doppler Ultrasound (DUS). Its imagery is completely novel and different from an atlas illustration, but red is still used to depict the arterial blood, while the venous blood is shown as blue. Finally, demonstrating the relationship between flow disturbances of the blood and the geometry of the vessel it is circulating within is a subject of ongoing investigation and the main focus of the research program in our laboratory, and it will be discussed in detail later on.
With Roentgen’s discovery, a series of related innovations and applications were developed that led to previously unimaginable discoveries in the field, This was because the initial accidental discovery was almost immediately followed by well-designed experiments that helped calibrate and adjust the apparatus and, subsequently, angiography was born from the idea of replacing blood with a radio-opaque dye. The first angiogram was, in fact, an X-ray image of an amputated hand into which a radio-opaque mixture was injected and was apparently made less than a month after the first X-ray image (Glassner, 1992). In order to reflect this change in understanding and knowledge in the angiology field, visual representation moved from depicting the shape and location of blood vessels in the human body to trying to understand causes and patterns of normal and altered blood dynamics (see Fig 1, panel D).
During the last century and well into this century, blood flow was often represented as a literal illustration of Poiseuille’s Law2, and therefore it “simplifies reality” by ignoring the fact that the blood actually follows a pulsatile motion according to the heartbeat. The result was that the blood velocity profile across an artery was represented as a parabola (e.g., Malek et al. 1999). Later, Womersley extended Poiseuille’s Law to pulsating arteries and, as a result, the simple parabolic shape gave way to much more complex flow patterns which were represented by corresponding visual illustrations situated more on the technical and not the artistic side. (see Fig 2).
Fig 2 – Technical representations of blood flow as they evolved over the last half century: (A) pre-1950s simple mathematical models – Poiseuiile’s Law; (B) 1950s complex mathematical models – Womersley’s Law; (C) 1960s electrical analogs; (D) 1970s idealized physical models
Womersley’s equations were shown to be analogous to those governing electrical circuits. This led to the popularization of electrical analog models of the circulatory system3 that resulted in visual representations of blood vessels as electrical circuits (e.g. Fig 2, panel C.) This allowed investigators to elucidate how arterial diseases might affect the pressure pulse. It was hoped that such models could be used to infer the nature of vascular diseases simply from pressure measurement.
By the late 1960s, however, Caro and others had shown that the well-known localization of vascular diseases to arterial branches and bends could be explained by the presence of complex blood flow patterns at these sites (Caro 2009). This opened up a whole new line of investigation into local, rather than global, blood flow and engineers were brought to the table for their know-how in visualizing flow using physical models. Throughout the 1970s and ’80s, transparent glass and plastic models were routinely used to visualize flow according to various engineering flow visualization conventions (see Fig 3).
Fig 3 – Turn of the 21st century representations of blood flow: (A) 1980s, see-through glass and plastic models; (B) 1990s, CFD symmetrical model, using conventional engineering “rainbow” colour scheme; (C) 1990s, Doppler Ultrasound (warm colours for velocities towards the Doppler probe, and cool colours away from the probe),emulating, respectively, Doppler ultrasound and (E) 2000s, use of anatomical medical imaging to create patient-specific CFD models (emulating, respectively, Doppler ultrasound and the common engineering technique of seeding small reflective particles into flow.)
The 1990s were the decade when it became possible to carry out computational fluid dynamics (CFD) simulations of blood flow on desktop computers.4 A natural first step was to use the same geometries as the physical models. This made it easier to define them on the computer software available at the time and also to compare the CFD results against the experiments. The resulting images often used a conventional engineering rainbow colour scheme that was largely dictated by the software available at the time. Simultaneously, Doppler ultrasound (DUS) emerged as a front-line tool for imaging blood flow in vivo. Just as arteries are shown in red and veins in blue in anatomical texts, DUS employed the convention of red/warm colours for velocities moving towards the Doppler probe and blue/cool colours for those moving away from the probe.
As the technology became mainstream in medical research, the role of generating medical images – traditionally the artist’s fiefdom – was assumed by the engineer and the software developer. The traditional colour conventions were, for most part, perpetuated but with the broadening of the user field, changes and adjustments occurred. The most critical of all factors was the tension between the needs of the clinician and the different visual conventions of the engineers. Clinicians are familiar and thus more comfortable with “traditional” medical images such as medical atlas illustrations and radiographs. In contrast, the engineers have their own colour conventions and notations.
The process can be described as falling under the umbrella of two paradigms (see Fig 4). In the current paradigm (Paradigm 1), medical images of the patient serve, in addition to their usual diagnostic role, as the basis for constructing a computerized representation (i.e. model) of the insides of the patient, or part thereof (e.g., an artery). The additional diagnostic information provided by this “virtual patient” must then be communicated to the clinician in the form of an image.
Fig 4 (left) - Two paradigms in virtual imaging. Paradigm 1: the physician is informed by the real and virtual images. Paradigm 2: the physician is informed directly by the virtual patient, now progressively refined until there is no difference between the real and virtual images.
Initially, we represented our models within this paradigm using traditional engineering visualizations. However, before we knew it, the needs of the clinician, in conjunction with technological developments, caused and supported the shift towards using representations that mimicked the physics and visual conventions of medical imaging. In this way, such “virtual imaging” becomes an adjunct to conventional medical imaging.
In the case of the second paradigm (Sarvazyan, 1991), in addition to using real images to construct a virtual patient and then virtual images as described above, the difference between the real and virtual image is assessed and that information is used to refine the virtual patient. Once the virtual images are indistinguishable from the real images, one can assume the virtual patient is a simulacrum of the real patient. In principle at least, the clinician examining the virtual patient, inside and out, can generate a proper diagnosis. Within either of these paradigms, then, the clear, straightforward and fast communication of information to the clinician is paramount and a common visual vocabulary therefore crucial.
To address the issues at stake in a more compelling and illuminating way, we will refer to two examples from our practice in order to highlight the incredible freedom and versatility of the computer-generated medical image, as well as its present limitations, the challenges involved and the future expectations and possibilities.
Example #1 — Cerebral Aneurysm
The first case study (detailed in Steinman et al., 2003) is that of a giant aneurysm found in one of the patients treated by our clinical collaborator. The aneurysm was first “directly” imaged using X-ray angiography and treated using a technique in which soft platinum coils are fed up through arteries in the leg and into the aneurismal artery. After six months, the coils had compacted. This is significant as coils work by blocking flow into the aneurysm and thus allowing the blood to slowly clot and seal the aneurysm from the inside. If the coils compact, and therefore the blood flow permitted back, re-growth and/or rupture is probable. Our CFD-based computer-simulation of flow, based on a model of the aneurismal artery reconstructed from the high-resolution 3D X-ray imaging and viewed using a virtual particle visualization technique inspired by engineering visualizations, showed that the high velocities during systole are in the same direction as the coils were pushed and had compacted. Because of the crucial information content and its use by the clinician in critical decision-making regarding the treatment alternatives, we had to be, firstly, absolutely sure of the validity of our simulations and, secondly, able to communicate the data obtained in a manner comprehendible by the user. The four panels illustrate the different representations used in the process.
Figure 5 (above): Representations of a cerebral aneurysm: (A) x-ray angiogram of the aneurysm itself; (B) vector flow visualization; (C) particle flow visualization; and (D) slipstream flow visualization.
The first step was to generate a 3D image from the x-ray projections (an example of which is shown in the first panel of Figure 5). Additionally, we needed a digitized representation of the artery lumen.5 CFD then calculates the blood velocities at every location on the model. As shown in the second panel of Figure 5, the traditional engineering way to represent this data is by colour coding the velocity on a plane, or by using vectors. The in-plane velocity components are shown using vectors and portray a very detailed and complicated flow. This proved to be completely inscrutable to the clinician. The next representation was inspired by a common engineering flow visualization method, i.e., reflective particles lit up and filmed, and clearly shows the blood stream pushing the same direction that the coils were compacted. However, this data visualization was still not in a language familiar to the clinicians. Therefore we had to create an alternative CFD visualization approach that clearly communicated the high-speed jet entering the aneurysm. These were visuals they were accustomed to through exposure to the in-vitro “slip-stream” visualizations of neurosurgeon Dr. Charles Kerber. As shown in the last panel of Figure 5, essentially the same information was given but was made more accessible by adopting a familiar visual paradigm that was also very easy to translate into 2D as it maintained the conventional 2D sequential representation of a 4D phenomenon. This visualization method was developed by photographers Marey and Muybridge and brought to wider audiences by artists such as Balla, Carra and Duchamp.
As a side note, the four colours used in the slip-stream visualization were not related to any medical or engineering conventions but were chosen so they could be easily distinguished from one another. There is, therefore, no prior “meaning” to a specific colour.
Example #2 — Carotid Bifurcation
Figure 6: Different ways of visualizing fluid dynamic data: (A) isosurfaces of velocity; (B) isosurfaces of helicity; (C) wall shear stress; (D) streamlines; (E) pathlines. The same data were used to generate all five panels.
Another significant case study is the particular geometry of the carotid bifurcation, its impact on blood flow patterns and subsequent atherosclerotic plaque formation. This is important both from an epidemiological point of view, because of its morbidity and associated mortality, and because it is representative of the use of computer-generated visual representations of blood flow.
In the figure above we are demonstrating different ways of visualizing flow in a carotid bifurcation, in order the highlight the flow patterns thought to promote plaque formation. It is also another way of mapping blood flow; not however in the sense of locating the vessels within the body, but rather in defining the flow patterns within the vessel. Whilst all panels are representations of the same data, each of them conveys a slightly different yet important message and needs to be well understood by the ultimate user, the clinician. They represent:
A. Isosurfaces of cycle-averaged speed, with dark and light shades highlighting regions of fast and slow flow, respectively;
B. Isosurfaces of cycle-averaged relative helicity6, coloured to distinguish counter-rotating flow streams;
C. Flooded contours of cycle-averaged wall shear stress magnitude, highlighting regions of low shear;
D. Streamlines at peak systole, coloured according to instantaneous velocity magnitude using the conventional engineering “rainbow” convention of warm colours (keeping with the conventional red for fast moving particles and cool colours for the slower ones);
E. Pathlines of particles released at peak systole.7 In this last panel we subvert the traditional red/blue anatomical convention for colouring arteries versus veins in order to distinguish the blood that eventually goes to the brain (shades of red) from that feeding the face, eyes, etc. (shades of blue). This distinction was made to help highlight the fact that there is much mixing of blood within the bifurcation before it gets sent to the respective vascular territories.
The Role of the Artist
The various steps of blood flow experimentation, as well as the visual representation of the data collected, have been shown in order to emphasize the differences in appearance required to meet the needs of different target audiences. Engineers, anatomists and clinicians each rely on different visual conventions. A remark by artist Gordana Novakovic regarding her own experience in transcending disciplinary visual and aesthetic boundaries illuminates the problem: ‘To emphasize the focus on processes, […], I suggested a black-and-white approach. Both scientists found this idea problematic, because, in their own words, they ‘could think of the immune system only in red’.’ (Novakovic, 2009).
As mentioned in this paper and discussed in more detail elsewhere (Steinman and Steinman, 2007), representing the patient-specific numerical data within a visual paradigm familiar to clinicians (such as X-ray, MRI, CT scans and Doppler Ultrasound look-alikes) was part of our own challenges in addressing the clinical communication constraints. In her preface to Body Criticism (1993), Barbara Stafford wrote: ‘In today’s workplace, computer monitors “disembody” information into ghostly green or amber apparitions that float before our eyes’. This remark points to the ubiquity and ambiguity of the virtual image. Due to almost unobstructed circulation through a variety of media, appropriation of medical images represents one of the major challenges we are facing. Free passage from the restricted scientific or clinical realms to that of popular culture means we must impose boundaries to protect the images we generate from misappropriation and misinterpretation. This is a relatively new issue, brought about by the shared technologies and communication media. In the past, for example in Vesalius’ times, such precautions were uncomplicated: the high quality anatomical drawings meant for the Fabrica were very expensive and thus not readily available outside academia. The public’s curiosity was, we imagine, satisfied by the dissemination of “fugitive sheets” (original in German “Fliegende Bletter”, i.e., flying sheets or flyers) through dentists’ and barber shops (Carlino, 1999). Their illustrations were more rudimentary in terms of both information content and technical execution. Today, the public’s desire to acquire medical images is easily satisfied, as they find their way on to YouTube, DNAtube and even television via news media and documentaries. Ironically, the name of the Internet open resource ‘for surgical education’, offering ‘images, illustrations, photographs, animations, and multimedia resources in the Clinical Folios‘ is www.vesalius.com.
It is clear that medical images occupy an unusual position in the collective psyche, being placed at the junction of science, medicine, visual representations and society. They merge methods of expression and interests from apparently unrelated fields, and they move freely from macro to micro, from body to tissue, from outside to inside, from the seen to the hidden. The images may be specialized, but they quickly become easily recognizable, thus influencing visual culture and leaving an indelible imprint upon culture at large.
This relationship between medical imagery, social culture and the handicap experienced by the “monolingual” we found to be most honestly encapsulated in artist Linda Duvall’s statement (Duvall, 2002): ‘I felt very much that I was excluded from the potential offered by these images [because] I was not able to see the information contained within them, in the way that I felt I would approach most other photographic imagery’. Even when used by artists in very personal ways — such as “genetic” or MRI self-portraits (e.g. Garry Schneider, Linda Duvall, Chantal Gervais), the medical image enters the world carrying facts and data that challenge the ability of their audience to absorb and assimilate them. SymbioticA (2010) have pointed out that ‘While non-scientifically trained artists may have a limited ability to analyse the detailed veracity of scientific work, “outsiders” working in a different mental framework can bring both insights and distractions into the debates about the mechanisms, ethics and philosophy behind scientific work. This can only be effective if those same artists engage actively in the science and the debate so that they have enough understanding of the process and work to engage meaningfully with it.’
Today’s enthralment with new medical investigation techniques and technologies affects both scientists and artists equally. Contemporary artists approach and address the clinical aspect of the human body from different perspectives, according to their own perceptions, preoccupations and sensibilities. They may, for example, create the illusion of a laboratory or a museum of natural sciences (e.g. Ionat Zurr, Oron Catts, Suzanne Anker, Jennifer Willet, Adam Zaretsky, Cindy Stelmackowich, Boo Chapple – to name just a few). Some seek to redefine identity by way of quasi-clinical self-examination (such as the well known examples of Stelarc, Mona Hatoum, Gary Schneider, Julie Rrap, Kira O’Reilly).
This continuum of scientific and artistic research through ‘collecting, archiving, observing, speculating, abstracting, modeling, experimentally examining, and using analogies and metaphors’ (Reichle, 2009; p. 215) is without precedent and is of particular interest to us. Ethical and social implications of our research are forefronted in the public discourse surrounding the introspective artistic activities of, for example, Justine Cooper, Annie Cattrell, Gerard Beaulieu, Marc Didou, Kevin Todd, Linda Duvall — all of whom discuss MRI as both a research and a communication tool.
Our attention has been drawn to alternate ways of representing and interpreting our scientific data through encounters with two conceptual artists. One of these instances was experiencing Nina Leo’s very personal installation Traces (Leo, 2003). The artist’s statement set the stage for us: ‘In this work forensic evidence in the form of […] blood […] samples are collected, catalogued and re-presented to the viewer. This mundane detritus is installed as sculptural artifacts, inviting the viewer to experience them in physical reality. Yet, as the context and meaning of this evidence remains ambiguous, it may reveal more about the viewer than about the subject. As with all mediated information, this evidence offers no resolution to any one truth.’ We were struck by our own bias looking at the delicate blood drops, full of meaning and biological data, trapped between the thin glass sheets of the microscope slides and arranged sequentially either like a house of cards or side by side and not as moving images of flow, their message being so different from the one carried by our images, but the substance being the same. Our strongly embedded visual references were challenged and we were inspired by Nina Leo’s different representation of our research subject.
Not long after, an encounter with Lorraine’s Berry’s interpretation of the world around in as Seasons Change (Berry, 2007), raised our awareness in the possibility of a different kind of representing scientific numerical data. The work involved both solar radiation data and numerical recordings of atmospheric warming trends that were translated into musical notes by a computer program, thus giving the public a poignant sense of a known, albeit unwelcome, phenomenon: climate change.
These two ways of interpreting the unseen yet palpable phenomena, so different from the scientific textbook model, made us question the creativity of our own visualizations and the possibilities our own data were offering.
Encouraged by the current widespread interest in medical research and data visualization and, in particular, by contemporary artists’ interest in and use of the resulting visual representations including the processing of raw numerical data, we are hoping to engage in a dialogue that will eventually create a new visual paradigm for medical representations of the human body in general and of blood flow in particular. Aside from the personal examples described above, the main reason to seek collaborations with artists, and to be aware of the research and production of knowledge originating in the artistic realm is our conviction that major advances in science were precipitated, at least in part, by radical changes in the artistic expression of the time. Admittedly there is little hard evidence to support the hypothesis that Einstein’s revolution of our world-view would have not been possible without the Futurists’ and Cubists’ interest in science and alternate representations of perceived reality (Shlain, 2007; p. 198). We base our belief on the anecdotal evidence that indicates that great thinkers and scientists such as Galileo, Pauling, Watson and Crick were able to shift paradigms due to their ability to see beyond ingrained ways of thinking by creating new visual models. The impact of the visual arts as the key that opened new ways to represent unknown or little understood phenomena is apparent in many cases in which major steps forward in science were made — from the huge leap of Copernicus’ heliocentric model to the more “modest” such as Pauling’s molecular interactions and Feynman’s quantum electrodynamics.
We can conclude that our own limitation in terms of the visual representations generated by our laboratory, is twofold: a) on an aesthetic level, we lack the rigorous artistic training and are thus limited by the visual vocabulary characteristic of each of the disciplines involved (i.e. medicine, physics, engineering, computer science); b) on a conceptual level, the use of the same visual representations and conventions perpetuated by the computer when translating data into images limits the understanding of the phenomenon by not including possible alternative visual representations of the same set of data. Striving to keep up with the new information provided to us by sophisticated apparatus collecting ever more detailed data, we turn towards the arts in searching for more refined ways to interpret it. Initiatives like the Science Gallery and SymbioticA — to name a couple of the ones we are most familiar with — are good examples of different, yet constructive, approaches in bringing art, technology and scientific research together.
For the time being, there are no results we can share but the ball has been set in motion. We have entrusted a photographer with our raw data and are anticipating surprising and exciting ways of visualizing them. At the same time, we were contacted by a young artist versed in new technologies and with a keen interest in scientific research and its visual representations. She has proposed to use the visualizations we generated in an art project addressing the emotions that the visuals alone would evoke, and connecting them, on an imaginary, exploratory level to the actual phenomenon. Additionally we are currently involved in a collaborative project in which various disciplines, departments and institutions will take part with the ultimate goal of exploring ways of analyzing scientific data and visually representing scientific phenomena, adopting the right practices and selecting the appropriate aesthetics in an effort to enable cross-disciplinary dialogue and better ways of communication.
Biographies
Dr. Dolores Steinman trained as a paediatrician, before finishing doctoral and postdoctoral research in cancer cell biology. An accomplished photographer, she is interested in the relationship/connection between humanities and biomedical research, with particular concern on patient data visualization. Dr. Steinman is currently a Guest Researcher at the University of Toronto.
Dr. David Steinman has spent more than a decade working to integrate the fields of computer modeling and medical imaging. He is a Professor of Mechanical and Biomedical Engineering at the University of Toronto, where he heads the Biomedical Simulation Laboratory. In his daily practice he is confronted with the various aspects of visually representing numeric data. Dr. Steinman holds a Career Investigator award from the Heart & Stroke Foundation.
URL: http://www.mie.utoronto.ca/labs/bsl
Endnotes
1. Many other examples demonstrating the influence of the artistic manner and style of the time on medical illustrations abound. They include that of Juan Valverde de Hamusco’s collaboration with the illustrator Gaspar Becerra (trained by Michelangelo), Berengario da Capri’s atlas and the background landscapes in its illustrations (Olfield and Landon, 2006; p. 27), Charles Estienne’s display of characters clearly copied from Caraglio’s work (Olfield and Landon, 2006; p. 22), and Dr. Samuel Pozzi’s (1890) Treatise of Gynecology with its beautiful botanical-looking arrangements of the specimens.
2. Jean Louis Marie Poiseuille was a 19th century physiologist who originally trained as an engineer at the Ecole Polytechnique. His careful measurements of flow and pressure in capillary tubes established a law relating the two, from which it was later derived mathematically that the velocity profile takes on the shape of a paraboloid.
3. The circulatory system can, with some approximation, be shown to obey the same mathematical equations that govern the behavior of AC electrical circuits: the frictional resistance of flowing blood being analogous to electrical resistance; the transient storage and release of blood due to compliance of the blood vessels being analogous to the storage and release of charge by electrical capacitors; and the inertia of the pulsating blood producing behavior much like that of an electrical inductor.
4. The equations governing fluid flow are too complex to solve by hand, except for trivial or contrived configurations. In computational fluid dynamics (CFD), a domain is broken up into many smaller, simpler shapes, over each of which a form of the fluid flow equations is defined. Because these shapes are connected together, this requires the simultaneous solution of often millions of equations, something only feasible by computer.
5. As noted earlier, CFD relies in the discretization of a complex domain into many smaller, simpler ones. A digitized representation of the artery lumen is the necessary starting point for this process.
6. Helicity is a mathematical quantity derived from the velocity field, and essentially represents the degree of twisting within the flow field.
7. Streamlines reflect the trajectories that blood particles would follow if the velocity field were fixed at that instant in time. Pathlines account for the fact that the velocity field is changing with time, and so is a truer reflection of the actual trajectories of blood particles.
References
Berry, Lorraine, http://www.lorraineberry.com/book/book.html, Accessed 12 January 2010.
Carlino, Andrea. ‘Paper Bodies: A Catalogue of Anatomical Fugitive Sheets 1538-1687′, Med Hist Suppl 19 (1999): 1-352.
Caro, Colin G. ‘Discovery of the Role of Wall Shear in Atherosclerosis’, Arteriosclerosis, Thrombosis, and Vascular Biology 29 (2009): 158.
DeBakey, Michael E., Lawrie, Gerald M., Glaeser, Donald H. ‘Patterns of Atherosclerosis and their Surgical Significance’, Annals of Surgery 201 (1985): 115-131.
Duvall, Linda. ‘Bred in the Bone (Artist’s statement)’, Winnipeg’s Floating Gallery (2002).
Elkins, James. The Domain of Images (Ithaca: Cornell University Press, 1999).
Glassner, Otto. Wilhelm Conrad Roentgen and the Early History of the Roentgen Rays (Norman Publishing, 1992).
Kendall, Calvin N. Pictured Knowledge (Chicago: Compton-Johnson Publishing, 1919).
Kahn, Fritz, Das Leben des Menschen: eine volkstamliche Anatomie, Biologie, Physiologie und Entwick-lungs-geschichte des Menschen (Stuttgart: Franckh, 1926).
Leo, Nina, http://www.ninaleo.com/CurrentWorks.html, Accessed 12 January 2010.
Malek, Adel. M., Alper, Seth L., Izumo, Seigo. ‘Hemodynamic Shear Stress and its Role in Atherosclerosis’, Journal of the American Medical Association 282 (1999): 2035-42.
Myers, Natasha. ‘Conjuring Machinic Life’, Spontaneous Generations 2 (2008): 112.
Novakovic, Gordana. ‘Fugue and Variations on Some Themes in Art and Science’, EVA 2009 Conference (London, 6-8 July 2009).
Oldfield, Philip and Landon, Richard (eds.). Ars Medica: Medical Illustration Through the Ages (Toronto: University of Toronto Press, 2006), 27.
Pozzi, Samuel. Traité de gynécologie clinique et opératoire (Paris: G. Masson, 1890).
Reichle, Ingeborg. Art in the Age of Technoscience: Genetic Engineering, Robotics, and Artificial Life in Contemporary Art (Wien: Springer, 2009).
Sarvazyan, Armen P, Lizzi, Frederic L., Wells, Peter N. T. ‘A New Philosophy of Medical Imaging’, Medical Hypotheses 36 (1991): 327-335.
Shlain, Leonard. Art & Physics (New York: Harper Collins, 2007).
Stafford, Barbara Maria. Body Criticism: Imaging the Unseen in Enlightenment Art and Medicine (Cambridge: The MIT Press, 1993).
Steinman, David A., Milner Jaques S., Norley, Chris J, Lownie, Stephen P., Holdsworth, David W. ‘Image-based Computational Simulation of Flow Dynamics in a Giant Aneurysm”, American Journal of Neuroradiology 24 (2003: 559-66.
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