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INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE How to Utilize an Open Source DICOM Viewer and Properly Transmit Diagnostic Images in Your Practice Kurt Selberg, MS, DVM, MS, DACVR*; and Jeremiah T. Easley, DVM, MS, DACVS Author’s address: University of Georgia, Veterinary Biosciences and Diagnostic Imaging, 501 DW Brooks Drive, Athens, GA 30602 (Selberg); and Colorado State University, 300 West Drake Road, Fort Collins, CO 80523 (Easley); e-mail: [email protected]. *Corresponding and presenting author. © 2014 AAEP. 1. Introduction The adoption of digital imaging has been swift and recent. The greatest advantage of digital imaging is the ability to manipulate contrast, zoom in on areas of interest, make measurements, and transfer them via the Internet for consultation. However, for optimal benefit, this adoption requires more technical “know how.” As such, the need for image visualization and analysis has extended beyond the light box. Software for digital imaging and communications in medicine (DICOM) image viewing is often expensive, challenging to navigate, and limited in accessibility. Because of this, practitioners often send and receive radiograph, ultrasound, computed tomography, or magnetic resonance as lossy compressed images with .jpg or .jpeg (Joint Photographic Experts Group (JPEG)) file extensions for consultation on cases. However, when a diagnostic image is exported as a JPEG image important metadata and information in the DICOM header that tells the detector system, the radiographic technique, institution obtaining the radiographs, compression levels, and a host of other information is NOTES 332 2014 Ⲑ Vol. 60 Ⲑ AAEP PROCEEDINGS stripped. Most importantly, the information of scale is also stripped, so measuring lesions is not reliable. Furthermore, JPEG images are difficult to manipulate in a way to ensure that the reader is able to properly evaluate the entire image. Therefore, it is important that practitioners realize the advantage of reading and sharing DICOM images. In order to share DICOM images, practitioners must have access to simple, user-friendly, and free/ affordable DICOM imaging software and easy methods to transfer images to colleagues and specialists. Osirixa is an open source Mac OSX-based image processing application for DICOM image viewing. It is free and downloadable software from the Internet. This user-friendly software will aid practitioners in not only evaluating their own images such as radiographs and ultrasound, but it will allow them to manipulate, illustrate, and prepare images and even videos for presentations to clients and colleagues. Osirix is specifically designed to navigate and visualize 2D and 3D images while at the same time acting as a DICOM picture archiving and communication system (PACS) workstation (it can also INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE Fig. 1. The database window of Osirix with a list of the patients. The bottom half of the window displays the thumbnail previews. Along the right, there is a list of current and prior studies displayed. handle 4D and 5D, but that is outside the scope of this discussion). Additionally, this program will easily transmit images via DICOM transfer or export the DICOM images for transfer via free file sharing programs. Learning to use software such as Osirix will improve practitioners’ ability to evaluate medical images, consult with other professionals on cases, and even provide increased understanding of cases to clients. This article aims to provide practitioners with an overview of the many capabilities of Osirix, an open source DICOM imaging software and file-sharing options.1 2. Materials and Methods Software An open source stand-alone application has been developed that serves as a DICOM viewer and PACS. Osirix can be downloaded at www.Osirixviewer.com to run on the latest version of OsX.. There are alternatives for the Windows users such as Ginkgo CADx,b however this “how to” will be confined to Osirix and free file-sharing software. There are numerous download options to choose from, including the free 32-bit version, a paid 64-bit version, a paid FDA approved 64-bit version for medical usage, and a paid version for iPad and iPhone users. Unless you are a radiologist or performing advanced imaging studies with very large volume sets, the free 32-bit version should suffice in most scenarios. The Osirix program offers all the basic image manipulation functions of zoom, pan, contrast adjustment, image orientation, and measure, as well as allowing annotation and database organization by client or diagnosis. It also has the ability to hang multiple relevant prior exams. Additional advanced functions that can be performed include multiplanar reconstructions, convolution filters, variable slice thickness adjustments, volume rendering, minimum and maximum intensity projections, and surface rendering. There are several free file-sharing programs commercially available. Dropbox, Google Drive, and Microsoft Onedrive are the most notable. Only Dropbox will be explored in depth in this “how to.”2 A Dropbox account can be created and the software can be downloaded at www.dropbox.com. This is available for Windows, OsX, as well as mobile versions. Dropbox is an installable program or webbased program that syncs images on a personal computer as well as a remote server, also known as the cloud. This program allows folders and files to AAEP PROCEEDINGS Ⲑ Vol. 60 Ⲑ 2014 333 INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE Table 1. Fig. 2. This is the diagnostic window with a sagittal plane magnetic resonance image of the foot. The tool bar is located at the top of the screen with common tools such as pan, zoom, and window on the left side. Osirix automatically detects the number of displays and uses all available real estate to display the study. While the cursor is over the image, a right mouse click will also give options to change the mouse function. By default, left click is window/level, right click is zoom, and scroll is performed by dragging a finger forward and back. be shared using links to the file storage site rather than e-mailing the entire files, which circumvents e-mail server limits on attachment file size. 3. Results Both authors use Osirix almost exclusively to view 10 to 30 studies daily comprised of both clinical as well as research cases in an academic setting. One author uses Osirix as a PACS and web server as well as a DICOM viewer for the purposes of teleradiology. The study modalities are radiographs, ultrasound, nuclear medicine, magnetic resonance imaging, and computed tomography. Additionally, photographs or videos of patients included in prepurchase exams may be imported and reviewed. The database window shows the list of patients (Fig. 1). From this window, there are a variety of options for the selected patient. Double clicking on the patient will open the image viewer (Fig. 2). 334 2014 Ⲑ Vol. 60 Ⲑ AAEP PROCEEDINGS List of Hot Key Actions in Osirix Action Key Default window width and window level Flip vertical Flip horizontal Zoom Pan/move Rotate Measure length Measure angle Text Arrow ⬃ V H Z M I L A T Q Once the viewer is open, there is a customizable tool bar with icons and descriptive words for the icons along the top of the screen. The icons represent tools to manipulate the images. The most common tools used during review are the pan, zoom, and contrast. However, there are a variety of tools that are underutilized by practitioners, including arrow and text tools to annotate images. The default tool for the left click on the mouse is contrast. By default, right click (if you are using a single button mouse or touch pad, clicking and simultaneously holding down the control key is the same as a right click) and hold will allow the user to zoom centered on where the pointer is. The user can change the left click tool by clicking on the icons in the toolbar or right clicking and choosing. You can use the keyboard to reduce the number of mouse clicks. For example, holding down the option key with the left mouse click causes the curser/pointer to become the pan tool. When released, it returns to contrast. Using hot keys also may increase productivity (Table 1). Osirix also has built in capabilities to display the current and relevant prior studies. If connected to your home or remote back up server, it will automatically check to see if there are additional studies for the current patient. Osirix has robust capabilities to reconstruct surface renderings and cut away specific bones and soft tissue in cross sectional imaging. This capability is used by the authors weekly, if not daily, for surgical planning and teaching. Right clicking on a study in the database window will give you several options, including export. A variety of options for exporting images are available. Exporting as DICOM file(s) is the appropriate choice for transmitting radiographs through filesharing applications. Once this is selected, a window appears asking where to save the resulting file (Fig. 3). If you have already set up Dropbox, this folder will appear in the favorites bar in the finder window. There are also several options to check in the export window. The defaults settings are correct, which are checked boxes next to add DICOMDIR, hierarchical folder tree, don’t modify the files for compression, and save as ZIP. The INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE Fig. 3. Export window. By right clicking on the patient study in the database, an option for export is displayed. options for saving the study. The displayed settings are the most helpful. authors recommend compressing (zipping) the diagnostic images (Fig. 3). This can be password protected if needed. This may be done by adding the desired password under the zip option. This also acts as a single file rather than multiple and is often easier to manage. Once in the Dropbox folder, the integration of the program allows a link to be generated (Fig. 4) for the file by right clicking on the file and selecting “share link.” This link is then pasted into an electronic mail message and sent to a selected recipient. 4. Discussion Osirix image viewing software and Dropbox file sharing software have revolutionized consultation capabilities within the medical field. Positive collaboration and consultations between practitioners and specialists is vital to the overall success of the patient. With the increased utilization and improved access to advanced imaging in equine veterinary medicine, this collaboration becomes even more important. Advanced imaging modalities such as computed tomography and magnetic resonance imaging are growing rapidly due to high The window gives sensitivity and specificity for pathologic change. However, the success cannot be achieved without accurate evaluation of the images produced by these modalities. Equally important is the ability of the image evaluator to describe and illustrate image findings in order to ensure an appropriate clinical therapeutic plan. As previously mentioned, similar products as an alternative to Osirix for Windows-based users are available. One of the easier programs to navigate is Ginkgo CADx (http://ginkgo-cadx.com/en/downloads/). This also comes in a variety of download options for free with limited support to a paid version that offers professional support. The program is feature-rich with basic abilities similar to Osirix such as pan, zoom, magnify, measure, and DICOM send features. The minimum system requirements for Osirix are summarized (Appendix 1). Similar recommendations should be employed on a Windows-based computer. The advantage of the 64-bit system is its use of system memory for performing tasks. As previously outlined, in large data sets such as cross sectional imaging, more memory must be allocated to AAEP PROCEEDINGS Ⲑ Vol. 60 Ⲑ 2014 335 INNOVATIVE IMAGING TECHNIQUES TO ENHANCE THE QUALITY OF YOUR PRACTICE is best in a dimly lit room. This increases the perceived contrast of the image and reduces glare on the screen. The veterinarian often is encountered with clients wanting the images of the patient. Similar to other DICOM viewers, Osirix allows for the studies to be packaged with a “lite” version of the Osirix viewer and a Java-based DICOM viewer. In this regard, the packaged viewer is capable of displaying the images on both Apple and Microsoft operating systems. The Java based viewer comes with pan, zoom, window width, and level capabilities. In summary, it is important that practitioners have an understanding of the advantages to DICOM image viewing and file-sharing. Osirix is easy to learn and can quickly become indispensible software to any practitioner utilizing digital imaging equipment in their practice. As such, Osirix can help bridge the gap between practitioners and specialists, which can lead to advancements in diagnostic capabilities, increased disease understanding, successful therapeutic planning, and ultimately improved clinical outcomes and client satisfaction. Acknowledgments Conflict of Interest The Authors declare no conflicts of interest. Appendix 1 The hardware recommendations for Osirix are outlined: ● ● Fig. 4. This is the right click option of the exported study saved in the Dropbox folder. By selecting the “share Dropbox link” a link is saved to the computer’s clipboard and is able to be pasted to an electronic message. the program. In cases of radiographic and ultrasound review, the 32-bit Osirix program will perform well. Recommendations for monitors to review cases on have been set by the American College of Radiology. Veterinary Radiology also uses the guideline that a 3 MP, medical grade, 350 cd/m2 monitor be employed. Newer liquid crystal display monitors often exceed this recommendation. The authors currently use Apple 27 in. displays with specifications of 3.7 MP, 375 cd/m2, and a contrast ratio of 1000:1. It should also be noted that viewing images 336 2014 Ⲑ Vol. 60 Ⲑ AAEP PROCEEDINGS MacOS X 10.8 or higher Intel processor For best performance: ● 2– 4 GB of RAM for Radiographic image review (DX and CR) ● 6 GB of RAM if you plan to open more than 800 images (CT and MRI, PET-CT) ● 8 GB of RAM for more than 1500 images (multi-slice CT and PET-CT) with OsiriX-64 bit ● 12 GB of RAM for more than 3000 images (cardiac or functional imaging) with OsiriX-64 bit References and Footnotes 1. http://www.osirix-viewer.com/AboutOsiriX.html 2. https://www.dropbox.com/ a b Osirix, Pixmeo SARL, Bernex, Switzerland, Ginkgo CADx, MetaEmotion S.L, Valladolid, Spain.