Jump to content

Search the Community

Showing results for tags 'meshmixer'.



More search options

  • Search By Tags

    Type tags separated by commas.
  • Search By Author

Content Type


Blogs

  • Embodi3d Test Blog
  • 3D Printing in Medicine
  • Cool Medical 3D-Printing
  • 3D Bio Printing by Paige Anne Carter
  • SSchoppert's Blog
  • Additive Manufacturing in Medicine
  • biomedical 3D printing
  • Bryce's Blog
  • Chris Leggett
  • 3D Models Help Improve Surgical Precision, Reduce Operating Time
  • Desktop 3D Printing in Medical Imaging
  • 3D Printing: Radiology corner
  • The Embodi3D.com Blog
  • descobar3d's Blog
  • 3D Printing in Anthropology
  • Learn to 3D Print: Basic Tools from software to printers
  • 3D printing for bio-medicine
  • 3D Biomedical Printing - by Jacob M.
  • Valchanov's Blog
  • Deirdre_Manion-Fischer's Blog
  • Matt Johnson's Biomedical 3D Printing Blog
  • Devarsh Vyas's Biomedical 3D Printing Blogs
  • Devarsh Vyas's Biomedical 3D Printing Blogs
  • Mike at Medical Models
  • TOP TEN THE MOST DOWNLOADED EMBODI3D

Forums

  • Biomedical 3D Printing
    • Hardware and 3D Printers
    • democratiz3D®
    • Software
    • Clinical applications
    • 3D Printable Models
    • Medical Imaging: CT, MRI, US
    • Science and Research
    • News and Trending Topics
    • Education, Conferences, Meetings, Events
    • Member Lounge (new!)
    • General
  • Classifieds, Goods and Services
    • General Classifieds - members post free
    • Services needed
    • Services offered
    • Stuff for sale/needed
    • Post a Job
    • Looking for work - visible only to members

Categories

  • democratiz3D® Processing
  • Bones
    • Skull and Head
    • Dental, Orthodontic, Maxillofacial
    • Spine and Pelvis
    • Extremity, Upper (Arm)
    • Extremity, Lower (Leg)
    • Thorax and Ribs
    • Whole body
    • Skeletal tumors, fractures and bony pathology
  • Muscles
    • Head and neck muscles
    • Extremity, Lower (Leg) Muscles
    • Extremity, Upper (Arm) Muscles
    • Thorax and Ribs Muscles
    • Abdomen and Pelvis muscles
    • Whole body Muscles
    • Muscular tumors and sarcomas
  • Cardiac and Vascular
    • Heart
    • Congenital Heart Defects
    • Aorta
    • Mesenteric and abdominal arteries
    • Veins
  • Organs of the Body
    • Brain and nervous system
    • Kidneys
    • Lungs
    • Liver
    • Other organs
  • Skin
  • Veterinary
    • Dogs
    • Cats
    • Other
  • Science and Research
    • Paleontology
    • Anthropology
    • Misc Research
  • Miscellaneous
    • Formlabs
  • Medical CT Scan Files
    • Skull, Head, and Neck CTs
    • Dental, Orthodontic, Maxillofacial CTs
    • Thorax and Ribs CTs
    • Abdomen and Pelvis CTs
    • Extremity, Upper (Arm) CTs
    • Extremity, Lower (Leg) CTs
    • Spine CTs
    • Whole Body CTs
    • MRIs
    • Ultrasound
    • Veterinary/Animals
    • Other

Product Groups

  • Premium Services
  • Physical Print Quotes

Find results in...

Find results that contain...


Date Created

  • Start

    End


Last Updated

  • Start

    End


Filter by number of...

Joined

  • Start

    End


Group


Found 8 results

  1. This tutorial is based on course I taught at the 2018 RSNA meeting in Chicago, Illinois. It is shared here free to the public. In this tutorial, we walk though how to convert a CT scan of the face into a 3D printable file, ready to be sent to a 3D printer. The patient had a gunshot wound to the face. We use only free or open-source software and services for this tutorial. There are two parts to this tutorial: Part 1: How to use free desktop software to create your model Part 2: Use embodi3D's free democratiz3D service to automatically create your model Key Takeaway from this Tutorial: You can make high quality 3D printable models from medical imaging scans using FREE software and services, and it is surprisingly EASY. A note on the FDA (for USA people): There is a lot of confusion about whether expensive, FDA-approved software must be used for medically-related 3D printing in the United States. The FDA recently clarified its stance on the issue.* If you are not using these models for patient-care purposes, this does not concern you. If you have questions please see the FDA website. If you are a DOCTOR, you can use whatever software you think is appropriate for your circumstances under your practice of medicine. If you are a COMPANY, selling 3D printed models for diagnostic use, you need FDA-approved software. If you are designing implants or surgical cutting guides, those are medical devices. Seek FDA feedback. *Kiarashi, N. FDA Current Practices and Regulations, FDA/CDRH-RSNA SIG Meeting on 3D Printed Patient- Specific Anatomic Models. Available at https://www.fda.gov/downloads/MedicalDevices/NewsEvents/WorkshopsConferences/UCM575723.pdf Accessed 11/1/2017. Part 1: Using Desktop software 3D Slicer and Meshmixer Step 1: Download the scan file and required software To start, download the starting CT scan file at the link below. Also, install 3D Slicer (slicer.org) and Meshmixer (meshmixer.com). Step 2: Open 3D Slicer Open Slicer. Drag and drop the scan file gunshot to face.nrrd onto the slicer window. The scan should open in a 4 panel view as shown below in Figure 1. Figure 1: The 4 up view. If your view does not look like this, you can set the 4 up view to display by clicking Four-Up from the View menu, as shown in Figure 2 Figure 2: Choosing the four-up view Step 3: Learning to control the interface Slicer has basic interface controls. Try them out and become accustomed to how the interface works. Note how the patient has injuries from gunshot wound to the face. Left mouse button – Window/Level Right mouse button – Zoom Scroll wheel – Scroll through stack Middle mouse button -- Pan Step 4: Blur the image The CT scan was created using a bone reconstruction kernel. Basically this is an image-enhancement algorithm that makes edges more prominent, which makes detection of fractures easier to see by the human eye. While making fracture detection easier, this algorithm does unnaturally alter the image and makes it appear more "speckled" Figure 3: Noisy, "speckled" appearance of the scan on close up view To fix this issue, we will slightly blur the image. Select Gaussian Blur Image Filter as shown below in Figure 4 Figure 4: Choosing the Gaussian Blur Image Filter Set up the Gaussian Blur parameters. Set Sigma = 1.0. Set the input volume to be Gunshot to face. Create a new output volume called "Gaussian volume" as shown in Figure 5. Figure 5: Setting up the Gaussian parameters When ready, click Apply, as shown in Figure 6. You will notice that the scan becomes slightly blurred. Figure 6: Click Apply to start the Gaussian Blur Image filter. Step 5: Create a 3D model using Grayscale Model Maker Open the Grayscale Model Maker Module as shown below in Figure 7. Figure 7: Opening the Grayscale Model Maker Set up the Grayscale Model Maker parameters. Select the Gaussian volume as the input volume, as shown in Figure 8. Figure 8: Choosing the input volume in Grayscale Model Maker Next, set the output geometry to be a new model called "gunshot model." Set the other parameters: Threshold = 200, smooth 15, Decimate 0.5, Split normals unchecked as shown in Figure 9. Figure 9: Grayscale Model maker parameters When done, click Apply. A new model should be created and will be shown in the upper right hand panel, as shown in Figure 10. Figure 10: The new model Step 6: Save the model as an STL file To start saving the model, click the save button in the upper left of the Slicer window as shown in Figure 11. Figure 11: The save button Be sure that only the 3D model, gunshot model.vtk is selected. Uncheck everything else, as shown in Figure 12. Figure 12: The Save dialog. Check the vtk file Make sure the format of the 3D model is STL as shown in Figure 13. Specify the folder to save into, as shown in Figure 14. Figure 13: Specify the file type Figure 14: Specify the folder to save into within the Save dialog. Step 7: Open the file in Meshmixer for cleanup Open Meshmixer. Drag and drop the newly created STL file on the meshmixer window. The file will open and the model will be displayed as in Figure 15. Figure 15: open the STL file in Meshmixer Get accustomed to the Meshmixer interface as shown in Figure 16. A 3 button mouse is very helpful. Figure 16: Controlling the Meshmixer user interface Choose the Select tool. In is the arrow button along the left of the window. Figure 17: The select tool Click on a portion of the model. The selected portion will turn orange, as shown in Figure 18. Figure 18: Selected areas turn orange. Expand the small selected area to all mesh connected to it. Use Select->Modify->Expand to Connected, or hit the E key. The entire model should turn orange. See Figure 19. Figure 19: Expanding the selection to all connected mesh. Next, Invert the selection so that only disconneced, unwanted mesh is selected. Do this with Select->Modify->Invert, or hit the I key as shown in Figure 20. Figure 20: Inverting the selection At this point, only the unwanted, disconnected mesh should be selected in orange. Delete the unwanted mesh using Select->Edit->Discard, or use the X or DELETE key as shown in Figure 21. At this point, only the desired mesh should remain. Figure 21: Deleting unwanted mesh. Step 8: Run the Inspector tool The Inspector tool will automatically fix most errors in the model mesh. To open it, choose Analysis->Inspector as shown in Figure 22. Figure 22: The Inspector tool The Inspector will identify all of the errors in the mesh. To automatically correct these mesh errors, click Auto Repair All as shown in Figure 23. Figure 23: Auto Repairing using Inspector The Inspector will usually fix all or most errors. In this case however, there is a large hole at the edge of the model where the border of the scan zone was. The Inspector doesn't know how to close it. This is shown in Figure 24. Figure 24: The inspect could not fix 1 mesh error Step 9: Close the remaining hole with manual bridges Using the select tool, select a zone of mesh near the open edge. The Select tool is opened with the arrow button along the left. Choose a brush size -- 40 is good -- as shown in Figure 25. Figure 25: Choosing the select tool The mesh should turn orange when selected, as shown in Figure 26. Figure 26: Selected mesh turns orange. Next, rotate the model and select a zone of mesh opposite the edge from the first selected zone, as shown in Figure 27. Figure 27: Selecting mesh opposite the defect. Once both edges are selected, create a bridge of mesh spanning the two selected areas using the Bridge operation: Select->Edit->Bridge, or CTRL-B, as shown in Figure 28. Figure 28: The bridge tool There should now be a bridge of orange mesh spanning the gap. Click Accept, as shown in Figure 29. Figure 29: The new bridge. Be sure to click Accept. Next, repeat the bridge on the opposite side of the skull. Be sure to deselect the previously selected mesh before working on the opposite side, as shown in Figure 30. Figure 30: Creating a second bridge on the opposite side. Step 10: Rerun the Inspector Rerun the Inspector tool, as shown in Figure 31. Now with the bridges to "help" Meshmixer to know how to fill in the hole, it should succeed. If it fails, create more bridges and try again. Figure 31: Rerun the Inspector tool Next, export your file to STL. ' Figure 32: Export to STL Step 11: 3D print your file! Your STL file is now ready to be sent to the 3D printer of your choice. Figure 33 shows the model after printing. Figure 33: The final print Part 2: Using the democratiz3D service on embodi3d.com democratiz3D automatically converts scans to 3D printable models. It automates the mesh cleanup process and saves time. The service is free for general bone model creation. Step 1: Register Register for a free embodi3D account. The process takes only a minute. You need an account for your processed files to be saved to. Step 2: Upload the NRRD source scan to democratiz3D. From anywhere in the site, click democratiz3D-> Launch App Figure 34: Launching the democratiz3D app. Fill out basic information about your file. That information will be copied to your generated STL file, as shown in Figure 35. Figure 35: Entering basic file information Make sure democratiz3D processing is on. Choose an operation to convert your model. Set threshold to 200, as shown in Figure 36. Figure 36: Operation, threshold, and quality parameters. Click Submit! In 10 to 15 minutes your model should be done. You will receive an email notification. The completed model file will be saved under your account. Download the file and send it to your printer of choice! Figure 37; The final democratiz3D file, ready for download. That's it! I hope this tutorial was helpful to you. If you liked it, please rate it positively. If you want to learn more about democratiz3D, Meshmixer, or Slicer, please see our tutorials page. It has a lot of wonderful resources. Happy 3D printing!
  2. Hello everybody it's Dr. Mike here again with another medical 3D printing tutorial. In this tutorial we are going to be going over freeware and open-source software options for medical 3D printing. This tutorial is based on a workshop I am giving at the 2017 Radiological Society of North America (RSNA) Annual Meeting in Chicago Illinois, November 2017. In this tutorial we will be going over desktop software that can be used to create 3D printable anatomic models from medical scans, as well as a free online automated conversion service. At the end of this tutorial you should be able to make high-quality 3D printable models from a medical imaging scan using free software or services. Do I need to use FDA-approved software for Medical 3D Printing? Before I dive into the tutorial I'd like to take a minute to talk to learners from the United States about the US Food and Drug Administration (FDA) and how this federal agency impacts medical 3D printing. Many healthcare professionals are confused and concerned about the ability to use non-FDA-approved software for medical 3D printing. Software vendors sell software that has been FDA-approved, but the software is usually quite expensive, to the tune of many thousands of dollars per year in license fees. There has been a lot of confusion about whether non-FDA-approved free software can be used for medical applications. In August 2017 a meeting was held at the main FDA campus between FDA staff and representatives from RSNA. During this meeting the FDA clarified its stance on the issue (Figure 1). Basically the FDA indicated that if a doctor needs a 3D printed model for patient care, the doctor does NOT need to use FDA-approved software, as this is a medical decision and the FDA does not regulate the practice of medicine. FDA-approved software is not required even if the doctor is using the model for diagnostic use (Figure 2). If a company or other organization is marketing or designing software for diagnostic use, then that company or organization is required to seek FDA approval for that product. Basically if you are a physician or working on behalf of the physician and require a model, FDA-approved software is not required as long as you are not running a commercial service or company. Despite this leeway granted by the FDA's interpretation, I encourage anyone considering using freeware to create models for diagnostic use to use common sense and double check your findings before making any critical decision that could impact patient care. I also encourage you to look at the slides from the FDA presentation directly at the link below. Of course, none of this applies if you are not creating models for medical use. https://www.fda.gov/downloads/MedicalDevices/NewsEvents/WorkshopsConferences/UCM575723.pdf Figure 1: Title slide from the FDA presentation Figure 2: The relevant slide from the FDA presentation. Doctors creating 3D printable models for clinical and diagnostic use do not need to use FDA-approved software as this is considered practice of medicine, which the FDA does not regulate. Medical 3D Printing Overview In this tutorial we're going to go over two different ways to use free and open-source software to convert a medical imaging scan to a 3D printable model. This can be done using free desktop software or a free online service. The desktop software requires more steps and more of a learning curve, but also allows more control for customized models. The online service is fast, easy, and automated. However, if you want to design customized elements into your model, you'll not be able to. The overall workflow of the session is shown in Figure 3. Figure 3: Workflow overview Part 1: Free online service – embodi3D.com Step 1: Download the scan Please download the scan for this tutorial from the embodi3D.com website at the link below. You have to have a free embodi3D.com account in order to download. If you don't have an account go ahead and register by clicking on the "Sign Up" button on the upper right-hand portion of the page. Registration is easy and only takes about one minute. You will have to confirm your email address before your account is active, so make sure you have access to your email. Step 2: Inspect the scan If you don't already have it, download and install the desktop software program 3D Slicer from slicer.org (http://www.slicer.org/). Slicer is a free medical image viewing and research software application. We are going to use Slicer to view our scan. Once Slicer is installed, open the application. Drag-and-drop the file "CTA Head.nrrd" onto the Slicer window. Slicer will ask if you want to add the file, click OK. The scan should now show in Figure 4. If your window doesn't look this then select the Four Up layout from the Layouts drop-down menu. Figure 4: The 4 panel view and Slicer You can navigate and manipulate the images with Slicer using the various mouse buttons. Your left mouse button to adjust the window/level settings as shown in Figure 5. Figure 5: Use the left mouse button to adjust window/level. The right mouse button allows you to zoom into a specific panel, as shown in Figure 6. Figure 6: The right mouse button controls zoom. The scroll wheel allows you to move through the various slices of the scan, as shown in Figure 7. Figure 7: The mouse wheel controls scrolling Step 3: Upload the scan to embodi3D.com Now that we have an idea about what's in the scan, you can upload it to embodi3D.com for automatic processing into a 3D printable model. Go to https://www.embodi3d.com/. If you don't yet have a free embodi3D.com user account, you will need one now. Go ahead and register. The process only takes a minute. Under the democratiz3D menu, click Launch App, as shown in Figure 8. Figure 8: Launching the democratiz3D medical scan to 3D printable model automated conversion service. Drag and drop the file "CTA Head.nrrd" onto the upload panel, as shown in Figure 9. The NRRD file format is an anonymized file format so this transfer is HIPAA compliant. If you want to know more about how to create an NRRD file from a DICOM data set, please see my tutorial on the topic here. Figure 9: Drag-and-drop the scan file "CTA Head.nrrd" onto the highlighted upload panel A submission form will open up. The first part of the form will ask you questions about the source file you're uploading. The second part will ask about the new model being generated. Start with the first part of the form, as shown in Figure 10, and fill in information about your uploaded scan file, including a filename, short description, any tags you wish to use to help people identify your file, whether you wish to share the file with the community or keep it private, and whether you want to make the file free for download or for sale. Obviously if you keep the file private this last setting doesn't matter as nobody will be able to see the file except you. Figure 10: The first part of the form relates to information about your uploaded scan file. Make sure you fill in at least the required elements. In the second part of the form fill in information about your model file that will be generated, as shown in Figure 11. First of all, make sure democratized processing is turned on. The slider should be green in color, as shown in Figure 11. This is very important because if processing is turned off, you will not generate an output model file! Specify what operation you would like to perform on the scan, and whether you would like to generate a bone, muscle, or skin model. Also, specify the desired quality of the output model (low, medium, high, etc.) and whether you want the output model to be shared with the community (recommended) or private. If your file is going to be shared, choose a Creative Commons license that people can use it under. When you're satisfied with your parameters, click the Submit button. Figure 11: The second part of the form relates to information about your 3D printable model to be generated. Choose an operation, quality level, as well as privacy settings. Step 4: Download your finished 3D printable model. After anywhere between 5 to 20 minutes you should receive an email saying that your model processing is complete. The exact time depends on a variety of factors including the complexity of your model, the quality that you've chosen, as well as server load. Once you receive the email follow the link to the model download page. Alternatively you can find the model by clicking on your username at the upper right-hand corner of any embodi3D.com webpage and selecting My Files. Once you find your model page you can inspect the thumbnails to make sure the model meets your criteria, as shown in Figure 12. When you are ready click the download button, agree to the terms, and your model STL file will download to your computer. Figure 12: Download your file after processing is complete. That's it! Your 3D printable model is ready to send to a printer. The process takes about 2 to 3 minutes to enter the data, plus 5 to 15 minutes to wait for the processing to be done. The embodi3D.com service is batchable, so it is possible for you to upload multiple files simultaneously. The service will crank out models as fast as you can upload them. Part 2: Free desktop software – 3D Slicer and Meshmixer You can use the free software program 3D slicer and Meshmixer to generate 3D printable models. The benefit of using desktop software is that you have more control over the appearance of the model and which structures you want included and excluded. The downside of using desktop software is that software is complicated and somewhat time-consuming to learn. If you haven't already download 3D Slicer and Meshmixer from the links below. Be sure to choose the appropriate operating system for your computer. http://www.slicer.org/ http://meshmixer.com/ Step 1: Download the tutorial scan file and load into Slicer as described above in Part 1 Steps 1 and 2. Step 2: Create a surface model from the scan data. From within Slicer, open the Grayscale Model Maker module. In the Modules menu at the top now bar, select All Modules and choose the Grayscale Model Maker item, as shown in Figure 13. Figure 13: Selecting the Grayscale Model Maker module. You will now be taken to the Grayscale Model Maker module, which will convert the volumetric data in the CT scan to a surface model that can be used to create a STL file for 3D printing. In the parameters panel on the left side of the screen, make sure that the parameter set value is set to "Grayscale Model Maker", and the Input Volume is set to "CTA Head." Under Output Geometry, choose Create a New Model, since we wish to create a new output model. These parameters are shown in Figure 14. Figure 14: Input parameters for the Grayscale Model Maker module Set the Threshold value to 150 Hounsfield units. Also, set the Decimate value to 0.8 and make sure the Split Normals checkbox is unchecked. These are shown in Figure 15. When you're happy with your parameters, check Apply, and the grayscale model maker will work for a minute or so to create your surface model. Figure 15: Additional input parameters for the Grayscale Model Maker module Step 3: Save the surface model to an STL file. Now that you have generated a surface model, you are ready to export it to an STL file. Click on the Save button on the upper left-hand corner of the 3D Slicer window. A Save dialog box will pop up, as shown in Figure 16. Find the row that contains the item "Output Geometry.vtk." Make sure that the checkbox next to this item is checked. All other rows should be unchecked. In the File Format column, make sure that the file shows as STL. Finally, make sure that the directory specified in the third column is the one you wish to save the file to. When everything is correct go ahead and click Save. Your surface model will now be exported and STL file saved in the directory specified. Figure 16: The Save dialog box Step 4: Repair the model in Meshmixer The model is in STL format, but it has multiple errors in it which need to be corrected prior to 3D printing. We will do this in the freeware software program Meshmixer. Open Meshmixer, and drag-and-drop the just-created STL file "Output Geometry.stl" onto the Meshmixer window. The model will now open in Meshmixer. You will notice that the model is quite large, having about 300,000 polygons, as shown in Figure 17. Figure 17: Open the model in Meshmixer Navigating in Meshmixer is quite intuitive. The left mouse button uses tools and selects structures. The right mouse button is used to rotate the model. The scroll wheel is used to zoom in and out, as shown in Figure 18. Figure 18: Navigating in Meshmixer Run an initial repair on the model using the Inspector tool We will be able to get rid of most (but not all) errors using the automated Inspector tool. Click on the Analysis button on the left navigation pane and choose the Inspector tool. Inspector will run and highlight all of the problems with the model, as shown in Figure 19. As you can see there are many hundreds of errors. Click on the Auto Repair All button to automatically attempt to fix these. At least one error will remain after the end of the process, but don't worry we will fix that later. Click on the Done button. Figure 19: The Inspector tool shows errors in the mesh Remesh the model The Remesh operation recalculates all the polygons in the model, adjusting their size, and giving the model in more natural and less faceted look. Remesh and can also help to fix lingering mesh errors. First, select all the polygons in the model by hitting control-A. The entire model should turn orange, as shown in Figure 20. Figure 20: Selecting all the polygons in the model. Next, run the Remesh operation. Hit the R key, or choose Select-> Edit-> Remesh. The Remesh operation will now run, and will take approximately 1.5 to 2 minutes, depending on the power of your computer. This is shown in Figure 21. Figure 21: The Remesh operation. At the end of the Remesh operation, your model should have a much smoother and more natural appearance. You can adjust some of the Remesh parameters in the visualized pane, and the operation will recalculate. When you're happy with the result, click on the Accept button. This is shown in Figure 22. Figure 22: The model after the Remesh operation. Repeat the Inspector tool operation Now that we have re-mashed the model, we can rerun the Inspector tool to clean up any residual errors. Click on Analysis and then the Inspector menu item. Click Auto Repair All, and inspector should repair any problems that still remain. When you're finished, click the Done button, as shown in Figure 23. Figure 23: Running the Inspector tool a second time Expose the cerebral vessels. We are now going to take an extra step and make a cut through the crowd of the skull to expose the cerebral vessels. This can be easily achieved in about one minute. First, make sure to select all the vertices in the model by hitting control-A or using the menus Select-> Modify-> Select all, as shown in Figure 24. The entire model should turn orange to indicate that it is selected. Figure 24: Selecting all the polygons in the model prior to performing a cut. Next, start a plane cut by choosing Select-> Edit-> Plane cut. The plane cut will show on the screen. The portion of the model that is transparent will be cut off. The portion of the model that is opaque will be left behind. Move the plane by using the purple and green arrow handles. Rotate the plane by using the red arc handle, as shown in Figure 25. Figure 25: Move and rotate the plane cut using the arrow and arc handles. In this case we wish to move the plane cut to the four head, and rotated 180° so that the transparent portion of the cut is at the top of the head, and the opaque portion encompasses the face, jaw, and lower part of the skull. After you have finished positioning the plane, your model should look similar to Figure 26. When you're happy with position, click Accept. Figure 26: The best position of the plane cut tool The crown of the skull will now be cut off, exposing the cerebral vessels within the brain. This includes the anterior, posterior, and middle cerebral arteries as well as the venous structures such as the straight sinus and sigmoid sinuses, as shown in Figure 27. As you can see, this is a highly detailed model and excellent for educational purposes and teaching neurovascular anatomy. Figure 27: The final model Conclusion In this tutorial we learn how to create a 3D printable skull and vascular model utilizing the free online service from embodi3D.com, as well as free desktop software 3D Slicer and Meshmixer. Both methods have their advantages and disadvantages. Embodi3D.com has a very fast and easy to use service. The desktop software is more difficult to use and learn, but gives more flexibility in terms of customization. Alternatively, you can use a combination of the two techniques, for example generating your model on the embodi3D.com website and then performing custom modifications, such as the plane cut we did in this tutorial, utilizing Meshmixer. I hope you found this tutorial helpful and entertaining. Please give the tutorial a like. If you are engaged in medical 3D printing, please consider sharing your work on the embodi3D.com website. Thank you very much and happy 3D printing!
  3. tsehrhardt

    Meshmixer Plane Cut

    I came across how to use the "Create Pivot" tool in Meshmixer to more precisely place a "Plane Cut," but it doesn't always seem to place the pivot where I want it. My heads are in FH with nasion at x = 0 and I want to make cuts at precise distances from this point or at other known points from the origin (I have nasion at x = 0, left and right porion at y = 0 and z = 0). When I use the default pivot placement, it sometimes places it at the origin, which is perfect because I can use that or use the "Transform" tool to shift the pivot a specific distance. Anyways, even with the same settings, the pivot is not always placed at the origin, so I'm not getting a cut at 0 every single time. Has anybody played with this or have a better way of getting cuts at a precise location? Meshlab has a "Compute Planar Section" which lets me take a cut at say, x = 0, but then I have to extrude it to get a printable layer.
  4. Note: This tutorial accompanies a workshop I presented at the 2016 Radiological Society of North America (RSNA) meeting. The workflow and techniques presented in this tutorial and the conference workshop are identical. In this tutorial we will be using two different ways to create a 3-D printable medical model of a head and neck which will be derived from a real contrast-enhanced CT scan. The model will show detailed anatomy of the bones, as well as the veins and arteries. We will independently create this model using two separate methods. First, we will automatically generate the model using the free online service embodi3D.com. Next, we will create the same file using free desktop software programs 3D Slicer and Meshmixer. If you haven't already, please download the associated file pack which contains the files you'll need to follow along with this tutorial. Following along with the actual files used here will make learning these techniques much easier. The file pack is free. You need to be logged into your embodi3D account to download, but registration is also free and only takes a minute. Also, you'll need an embodi3D.com account in order to use the online service. Registration is worth it, so if you haven't already go ahead and register now. >> DOWNLOAD THE FILE PACK NOW << Online Service: embodi3D.com Step 1: Go to the embodi3D.com website and click on the democratiz3D menu item in the naw bar. Click on the "Launch democratizD" link, as shown in Figure 1. Figure 1: Opening the free online 3D model making service service democratiz3D. Step 2: Now you have to upload your imaging file. Drag and drop the file MANIX Angio CT.nrrd from the File Pack, as shown in Figure 2. This contains the CT scan of the head and neck in NRRD file format. If you are using a file other NRRD that provided by the file pack, please be aware the file must contain a CT scan (NOT MRI!) and the file must be in NRRD format. If you don't know how to create an NRRD file, here is a simple tutorial that explains how. Figure 2: Dragging and dropping the NRRD file to start uploading. Step 3: Type in basic information on the file being uploaded, including File name, file description, and whether you want to share the file or keep it private. Bear in mind that this information pertains to the uploaded file, not the file that will be generated by the service. Step 4: Type in basic parameters for file processing. Turn on the processing slider. Here you will enter in basic information about how you would like the file to be processed. Under Operation, select CT NRRD to Bone STL Detailed, as shown in Figure 3. This will convert a CT scan in NRRD format to a bone STL with high detail. You also have the option to create muscle and skin STL files. The standard operation, CT NRRD to Bone STL sacrifices some detail for a smoother output model. Leave the default threshold at 150. Figure 3: Selecting an operation for file conversion. Next, choose the quality of your output file. Low-quality files process quickly and are appropriate for structures with simple geometry. High quality files take longer to process and are appropriate for very complex geometry. The geometry of our model will be quite complex, so choose high quality. This may take a long time to process however, sometimes up to 40 minutes. If you don't wish to wait so long, you can choose medium quality, as shown in Figure 4, and have a pretty decent output file in about 12 minutes or so. Figure 4: Choosing a quality setting. Finally, specify whether you want your processed file to be shared with the community (encouraged) or private and accessible only to you. If you do decide to share you will need to fill out a few items, such as which CreativeCommons license to share under. If you're not sure, the defaults are appropriate for most people. If you do decide to share thanks very much! The 3D printing community thanks you! Click on the submit button and your file will be submitted for processing! Now all you have to do is wait. The service will do all the work for you! Step 5: Download your file. In 5 to 40 minutes you should receive an email indicating that your file is done and is ready for download. Follow the link in the email message or, if you are already on the embodi3D.com website, click on your profile to view your latest activity, including files belonging to you. Open the download page for your file and click on the "Download this file" button to download your newly created STL file! Figure 5: Downloading your newly completed STL file. Desktop software If you haven't already, download 3D Slicer and Meshmixer. Both of these programs are available on Macintosh and Windows platforms. Step 1: Create an STL file with 3D Slicer. Open 3D Slicer. Drag and drop the file MANIX Angio CT.nrrd from the file pack onto the 3D Slicer window. This should load the file into 3D Slicer, as shown in Figure 6. When Slicer asks you to confirm whether you want to add the file, click OK. Figure 6: Opening the NRRD file in 3D Slicer using drag-and-drop. Step 2: Convert the CT scan into an STL file. From within Slicer, open the Modules menu item and choose All Modules, Grayscale Model Maker, as shown in Figure 7. Figure 7: Opening the Grayscale Model Maker module. Next, enter the conversion parameters for Grayscale Model Maker in the parameters window on the left. Under Input Volume select MANIX Angio CT. Under Output Geometry choose "Create new model." Slicer will create a new model with the default name such as "Output Geometry. If you wish to rename this to something more descriptive, choose Rename current model under the same menu. For this tutorial I am calling the model "RSNA model." For Threshold, set the value to 150. Under Decimate, set the value to 0.75. Double check your settings to make sure everything is correct. When everything is filled in correctly click the Apply button, as shown in Figure 8. Slicer will process for about a minute. Figure 8: Filling in the Grayscale Model Maker parameters. Step 3: Save the new model to STL file format. Now it is time to create an STL file from our digital model. Click on the Save button on the upper left-hand corner of the Slicer window. The Save Scene pop-up window is now shown. Find the row that corresponds to the model name you have given the model. In my case it is called "RSNA model." Make sure that the checkbox next to this row is checked, and all other rows are unchecked. Next, under the File Format column make sure to specify STL. Finally, specify the directory that the new STL file is to be saved into. Double check everything. When you are ready, click Saved. This is all shown in Figure 9. Now that you've created an STL file, we need to postprocessing in Meshmixer. Figure 9: Saving your file to STL format. Step 4: Open Meshmixer, and drag-and-drop the newly created STL file onto the Meshmixer window to open it. Once the model opens, you will notice that there are many red dots scattered throughout the model. These represent errors in the mesh and need to be corrected, as shown in Figure 10. Figure 10: Errors in the mesh as shown in Meshmixer. Each red dot corresponds to an error. Step 5: Remove disconnected elements from the mesh. There are many disconnected elements in this model that we do not want in our final model. An example of unwanted mesh are the flat plates on either side of the head from the pillow that was used to secure the head during the CT scan. Let's get rid of this unwanted mesh. First use the select tool and place the cursor over the four head of the model and left click. The area under the cursor should turn orange, indicating that those polygons have been selected, as shown in Figure 11. Figure 11: Selecting a small zone on the forehead. Next, we are going to expand the selection to encompass all geometry that is attached to the area that we currently have selected. Go to the Modify menu item and select Expand to Connected. Alternatively, you can use the keyboard shortcut and select the E key. This operation is shown in Figure 12. Figure 12: Expanding the selection to all connected parts. You will notice that the right clavicle and right scapula have not been selected. This is because these parts are not directly connected to the rest of the skeleton, as shown in Figure 13. We wish to include these in our model, so using the select tool left click on each of these parts to highlight a small area. Then expand the selection to connected again by hitting the E key. Figure 13: The right clavicle and right scapula are not included in the selection because they are not connected to the rest of the skeleton. Individually select these parts and expand the selection again to include them. At this point you should have all the geometry we want included in the model selected in orange, as shown in Figure 14. Figure 14: All the desired geometry is selected in orange Next we are going to delete all the unwanted geometry that is currently unselected. To start this we will first invert the selection. Under the modify menu, select Invert. Alternatively, you can use the keyboard shortcut I, as shown in Figure 15. Figure 15: Inverting the selection. At this point only the undesired geometry should be highlighted in orange, as shown in Figure 16. This unwanted geometry cannot be deleted by going to the Edit menu and selecting Discard. Alternatively you can use the keyboard shortcut X. Figure 16: Only the unwanted geometry is highlighted in orange. This is ready to delete. Step 6: Correcting mesh errors using the Inspector tool. Meshmixer has a nice tool that will automatically fix many mesh errors. Click on the Analysis button and choose Inspector. Meshmixer will now identify all of the errors currently in the mesh. These are indicated by red, blue, and pink balls with lines pointing to the location of the error. As you can see from Figure 17, there are hundreds of errors still within our mesh. We can attempt to auto repair them by clicking on the Auto Repair All button. At the end of the operation most of the errors have been fixed, but if you remain. This can be seen in Figure 18. Figure 17: Errors in the mesh. Most of these can be corrected using the Inspector tool. Figure 18: Only a few errors remain after auto correction with the Inspector tool. Step 7: Correcting the remaining errors using the Remesh tool. Click on the select button to turn on the select tool. Expand the selection to connected parts by choosing Modify, Expand to Connected. The entire model should now be highlighted and origin color. Next under the edit menu choose Remesh, or use the R keyboard shortcut, as shown in Figure 19. This operation will take some time, six or eight minutes depending on the speed of your computer. What remesh does is it recalculates the surface topography of the model and replaces each of the surface triangles with new triangles that are more regular and uniform in appearance. Since our model has a considerable amount of surface area and polygons, the remesh operation takes some time. Remesh also has the ability to eliminate some geometric problems that can prevent all errors from being automatically fixed in Inspector. Figure 19: Using the Remesh tool. Step 8: Fixing the remaining errors using the Inspector tool. Once the remesh operation is completed we will go back and repeat Step 6 and run the Inspector tool again. Click on Analysis and choose Inspector. Inspector will highlight the errors. Currently there are only two, as shown in Figure 20. These two remaining errors can be easily auto repair using the Auto Repair All button. Go ahead and click on this. Figure 20: running the Inspector tool again. At this point the model is now completed and ready for 3D printing as shown in Figure 21. The mesh is error-free and ready to go! Congratulations! Figure 21: The final, error-free model ready for 3D printing. Conclusion Complex bone and vascular models, such as the head and neck model we created in this tutorial, can be created using either the free online service at embodi3D.com or using free desktop software. Each approach has its benefits. The online service is easier to use, faster, and produces high quality models with minimal user input. Additionally, multiple models can be processed simultaneously so it is possible to batch process multiple files at once. The desktop approach using 3D Slicer and Meshmixer requires more user input and thus more time, however the user has greater control over individual design decisions about the model. Both methods are viable for creating high quality 3D printable medical models. Thank you very much for reading this tutorial. Please share your medical 3D printing designs on the embodi3D.com website. Happy 3D printing!
  5. In this brief tutorial we will go over how to use Meshmixer to create a hollow shell from a medical 3D printable STL file. Hollowing out the shell, as shown in the pictures below, can allow you to 3D print the model using much less material that printing a solid piece. The print will take less time and cost less money. For this tutorial we will use a head that we created from a real medical CT scan in a prior tutorial, " Easily Create 3D Printable Muscle and Skin STL Files from Medical CT Scans" If you haven't seen the prior tutorial, please check it out. To follow along with the tutorial, please download the accompanying file. This will enable you to replicate the process exactly as it is shown in the tutorial. >> DOWNLOAD THE TUTORIAL FILE NOW <<
  6. Version 1.0.0

    62 downloads

    This file accompanies the tutorial "How to Create a Hollow Shell from a Medical STL Model using MeshMixer." Download the file to follow along with the tutorial.

    Free

  7. UPDATED TUTORIAL: A Ridiculously Easily Way to Convert CT Scans to 3D Printable Bone STL Models for Free in Minutes Hello and welcome back. I hope you enjoyed my last tutorial on creating 3D printable medical models using free software on Macintosh computers. In this brief video tutorial I'll show you how to create a 3D printable skull STL file from a CT scan in FIVE minutes using only free and open source software. In the video I use a program called 3D Slicer, which is available from slicer.org. 3D Slicer works on Windows, Macintosh, and Linux operating systems. Also, I use Blender, which is available from blender.org, to perform some mesh cleanup. Finally, I check my model prior to 3D printing using Meshmixer from Autodesk. This is available at meshmixer.com. All software programs are free. If you like this, view my complete tutorial where I go through each step shown here in detail. I hope you enjoy the video.
  8. mplishka

    Great Resources for modeling

    Hi all! Just wanted to share that Autodesk has some great free programs/apps for cleaning up imported files and for scanning and CAD. In particular, MeshMixer is an amazing piece of software. I've been playing with it to clean up some CT spine files and it is really easy to use and powerful. As someone who has used all levels of CAD software, I can't believe it's free. Check out the Autodesk resources here: http://www.123dapp.com/create Enjoy!! Mike
×