Osirix Imaging - Articles, Tutorials & Resources for Medical Illustrators

The utilization of MRI technology to view the equine hoof is relatively new to the equine veterinary field and so the use of this technology to create visuals is also in its infancy. The goal of my research at the University of Illinois at Chicago was to examine the different methods of rendering with the use of MRI data of the horse as the basis for producing illustrations and interactive visualizations with commercially available visualizing programs. Producing inter-actives and illustrations with actual data from the living equine is a significant step in veterinary education, as much of the equine has not been visualized in this way.

Magnetic Resonance Imaging (MRI) is a fairly new method being used as a diagnostic tool in equine veterinary medicine due to specific issues with taking MR images of the equine. It is becoming more popular because of improved methods and because MRI captures soft and dense tissue. For the first time we are able to visualize all the tissue in the living equine’s hoof.

Using MRI data as a basis for the anatomical illustrations means that the finished product is based on data from an actual animal, it is not a complete interpretation by the artist of anatomical structure. The artist can use his/her skill to enhance the images to highlight necessary information. The anatomy is then accurately rendered and various pathologies can be explored and compared to the normal. Using MRI data for the illustrations also means that the illustrations are useful for the education of veterinary students who will be utilizing MRI as a means to visualize their patients in the future. Software programs such as OsiriX, Adobe Flash and Adobe Premiere Pro enable biomedical artists to combine illustrations based on real data with educational inter-actives thus creating new tools for learning equine anatomy and interpreting equine anatomy in MRI.

Osirix was utilized in my research for viewing the data of a pathologic equine hoof. The University of Illinois at Urbana/Champlain veterinary hospital provided all the data. The data made available was from a 7.1 tesla MRI machine. Higher resolutions are possible but were not available to this researcher. OsiriX made it possible to view both the 2D transverse slices of the data used as well as to build both a 3D surface render and a virtual 3D render of the data which was then manipulated in OsiriX and or exported from OsiriX in various forms and imported into other software programs for further manipulation.

The following are the procedures I used to create different visuals:
Procedure 1: OsiriX/Adobe Photoshop
Procedure 2: OsiriX/Adobe Photoshop
Procedure 3: OsiriX/Adobe Photoshop
Procedure 4: OsiriX17
Procedure 5: OsiriX/Maya
Procedure 6: OsiriX/(VR) Quick Time movie/Adobe Flash
Procedure 7: OsiriX/(VR) QT movie/Adobe Premiere Pro
Procedure 8: OsiriX/(VR) Quick Time movie/eZedia QTI

Procedure 1: OsiriX/Adobe Photoshop

The first procedure was exporting individual DICOM files from Osirix as tiff files and then importing them into Adobe Photoshop to be colorized. It is a quick and easy way to differentiate certain aspects of the anatomy or to emphasize pathologies or small details without actually altering the original data. These illustrations would be very useful for learning to read MR images as they provide the differentiation of tissue and structures that black and white images do not. These colorized slides could be used as stand alone illustrations or exported to Adobe flash for use in an interactive module or as frames in Adobe Premiere Pro. It should be mentioned that it is also possible to directly open DICOM files with Photoshop CS3. Adobe Bridge can be used to view the slides before opening them.

Procedure 2: OsiriX/Adobe Photoshop

The second procedure was to export individual DICOM slides from Osirix as tiff files and then import them into Adobe Photoshop to be used as a ‘skeleton’ of an illustration. This was also a fairly easy was to create an accurate render. This method gives more artistic license, enabling the artist to further embellish the data resulting in more room for error if the desired result is to visualize the actual data. This procedure of illustration can create a beautiful illustration that is useful for learning anatomy in the context of MRI.

Procedure 3: OsiriX/Adobe Photoshop
Creating a 3D model of the full data set in Osirix, exporting 2D tiff files of certain views of the 3D model to Photoshop and colorizing them with transparent color layers proved to be a fairly quick and easy way to create interesting visuals without altering the data. Colorizing these images was slightly more difficult than colorizing the basic slides because of their 3D nature. These were then very easy to import into Flash or Premiere Pro for use in an interactive or as frames.

Procedure 4: OsiriX

Adjusting the color of the 3D model in Osirix, as well as adjusting the density of the image proved to be an easy method of visualization with a lot of potential for variety. Already colored tiffs of individual frames were simple to produce but did not allow the level of color differentiations that hand painting them in Photoshop provided. It did however, allow for density changes that would be extremely time consuming to produce in Photoshop. These images work well alone or mixed with photographs as I did. They could also be used with further illustration in Photoshop as well as in Flash or Premiere Pro for use in an interactive or as frames.

Procedure 5: OsiriX/Maya

Creating a surface render of the data set in Osirix and exporting it as an stl file to Maya did not prove to be very successful. The data set was only a section of a hoof but included all soft tissue information so that the final stl’s wire mesh was too complicated and slowly rendered an unrecognizable object.

Procedure 6: OsiriX/(VR) Quick Time movie/Adobe Flash

Using Osirix to export a VR Quick Time movie to Flash is a promising use of the data set for an interactive. Unfortunately when importing a Quick Time movie into Flash it lives on the timeline as a full movie not individual frames of a movie. In order to have it in the time line as individual frames, which are desirable because they are easier to manipulate, the fla file can be exported as tiffs and re-imported as individual frames on the timeline. Another resolution is to export individual frames as tiffs from Osirix but this proved to be more time consuming. Flash provides the most possibilities of interactive use but is unfortunately, not able to render out as a Quick Time VR movie.

Procedure 7: OsiriX/(VR) QT movie/Adobe Premiere Pro

The next procedure of exporting a virtual 3D Quick Time movie to Premiere Pro and then labeling particular frames was a fairly easy process. The one difficulty I found with this method was that the size of the tiffs that were exported from Premiere (originally from QT) to Photoshop were not compatible when returned to Premiere. They became distorted when transferred. I had to resize frames appropriately.

Premiere Pro and Quick Time Pro do not allow an export of a VR Quick Time movie so in order to render one the movie needed to be then exported to eZedia QTI. QTI is an authoring program that allowed me to render the movie out as a virtual Quick Time movie. This was not completely problem-free as it lost the use of the hand icon so that the object within the movie needs to be manipulated with the arrow keys.

Procedure 8: OsiriX/(VR) Quick Time movie/eZedia QTI

It is possible to work directly in eZedia QTI as in Premiere Pro, adding frames from Photoshop. QTI, unlike Premiere Pro and Flash, however, has the ability to render out a Quick Time VR interactive.

So for the final procedure I worked directly from Osirix to QTI, which is the easiest method of creating a QTVR if not the one with the most possibilities. QTI enables the artist to create simple interactive VR movies for the web, as well as for many other applications such as iPod and iPhone.

All procedures of this exercise in the different uses of MRI for the visualization of the equine hoof proved to be useful with the exception of the surface render from Osirix for use with Maya. Osirix proved to be great software to help produce these types of anatomical visualizations because of its ease in transferring data into other formats.



Rachel Monticelli earned a degree in Equine Science from Cazenovia College in 1991 and worked in the horse industry in various positions including: managing, training, instructing and as a feed specialist. In 2000 Rachel returned to school earning an AAS in Commercial Art from Dutchess Community College in 2002 a BFA in Studio Art from Cazenovia College in 2005 and finally Rachel graduated in 2008 with a Masters of Science in Biomedical Visualization from the University of Illinois at Chicago. This educational venue is one that enables Rachel to combine her artistic talent, love of teaching, and extensive knowledge of the horse, science and art to produce educational visuals.