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  1. 5 likes
    I was recently contacted by another doctor who asked if I could help him to create a 3D printed replicate of his spine to visualize pinched nerves in his low back and aid with planning a future back surgery. In order to work this doctor has to stand for long hours while performing surgical procedures. Excruciating low back pain had limited his ability to stand to only 30 minutes. As you can imagine, this means he couldn't work. Things only got worse after he had low back surgery. A CT scan of his lumbar spine (the low back portion of the spine) was performed. It showed that his fifth lumbar vertebra was partially sacralized. This means it looked more like a sacral vertebra than a lumbar vertebra. Was this causing his problem? On the image slices of the CT scan it was difficult to tell. How the Spine is Organized First, a word about the different vertebrae (bones) in the spine. There are four main sections of spinal bones. The seven cervical vertebrae are in the neck and support the head. They are generally small but flexible, and allow rotation of the head. The 12 thoracic vertebrae are in the chest. Their most distinctive characteristic is they all have associated ribs, which make up the rib cage. The five lumbar vertebrae are in the low back. These are large and strong, and designed for supporting lots of weight. They do not have associated ribs. The five sacral vertebrae are in the pelvis. In adults, they are fused together and effectively form a single bone, the sacrum. The coccyx, or tailbone, which is a tiny bone at the bottom end of the vertebral column, can be considered a fifth spinal section. This is the bone that is often injured when you fallen your behind. Figure 1 shows the different sections of the vertebral column. Figure 1. Sections of the vertebral column. Source:aimisspine.com Although the bones of the individual sections of the spine usually have their own unique features, it is not uncommon for vertebrae in one section to have features typically associated with an adjacent section. This is particularly true of the vertebrae that are immediately adjacent to a neighboring section. These hybrids are a mix between both sections, are called transitional vertebrae. Do you recall that only thoracic vertebrae have associated ribs? Occasionally the highest lumbar vertebra, L1, will have tiny ribs attached to it. This is a normal variant and is usually harmless. Radiologists who are interpreting medical scans need to be careful to not confuse an L1 vertebra which may have tiny ribs for the adjacent T12 vertebra which normally has ribs. Similarly, the lowest lumbar vertebra, L5, which is normally unfused, can exhibit fusion. As you recall, fusion is a characteristic of sacral vertebrae. A Congenital Spine Abnormality This was the situation with our physician. His lowest lumbar vertebra, L5, has partially fused with S1, the highest sacral vertebra. This condition is congenital. He has had it all his life. The fusion can have the side effect of creating a very narrow bony canal through which the L5 nerve roots can exit the spine. Normally, these nerve roots would have much more space as a large gap would exist between the normally unfused L5 and S1 vertebrae. Was this the problem? The CT scan showed the sacralization of L5, but it was difficult to get a sense for how tight the holes through which the nerves exit, the neural foramina, were. See Figures 2 and 3. Figure 2: Coronal CT image through the L5 and S1 vertebral bodies. Is this the cause of the problem? It is very difficult to get an intuitive sense of what is going on with these flat image slices. Figure 3: Image from Figure 2 with the neural foramina marked. Seeking help through Embodi3D The doctor contacted me through the Embodi3D website and asked if I could create a 3D model design and 3D print of his lumbar spine to help him and his team of spinal specialists understand his unique anatomy better. Of course, I was happy to help. The CT scan was of high quality and allowed me to extract the bones and metallic spinal fusion implants with little trouble. The individual nerves, however, were very difficult to see even on a high quality CT scan. I had to manually segment them one image at a time, which was a very tedious and time-consuming process. After fusing everything together, I had a very good digital model of the lumbar spine. I created some photorealistic 3D renders to illustrate the key findings. Figures 4 and 5 show the very tight L5-S1 bony neural foramina. The inter-vertebral disc sits within the gap between the two vertebral bodies, and you can see how a lateral bulge from this disc would significantly pinch these exiting nerve roots. Figure 4: Right L5 nerve root (yellow) exiting the tight neural foramen caused by the fused L5 and S1 lateral processes. Figure 5: Left L5 nerve root (yellow) exiting the tight neural foramen caused by the fused L5 and S1 lateral processes. Additionally, I showed that a bone screw that had been placed during the last surgery had partially exited the L4 vertebral body and was in very close proximity, and probably touching, the adjacent nerve root. Ouch! This can be seen in Figure 6. This may explain why the pain seem to get worse after the last surgery. Figure 6: Transpedicular orthopedic screw which has partially exited the L4 vertebral body and is in very close proximity or in contact with the right L3 nerve root. The Final 3D Printed Spine Model The doctor wanted his spine 3D printed in transparent material, so I used a stereolithographic printer with transparent resin. I printed the spine in two separate parts that could be separated and fit together. When separated, the nerves exiting through the neural foramina can be inspected from inside the spinal canal, which gives an added degree of understanding. Final pictures of the transparent 3D printed model are shown below. I just recently shipped the model to this doctor and don't yet know how his back problems will be resolved. With this 3D printed model in hand however, he will be able to have much more meaningful discussions with his spinal surgeons about the best way to definitively fix his low back problems. I hope that the 3D printed spine model will literally help to get this good doctor back on his feet again.
  2. 4 likes
    Getting from DICOM to 3D printable STL file in 3D Slicer is totally doable...but it is important to learn some fundamental skills in Slicer first if you are not familiar with the program. This tutorial introduces the user to some basic concepts in 3D Slicer and demonstrates how to crop DICOM data in anticipation of segmentation and 3D model creation. (Segmentation and STL file creation are explored in a companion tutorial ) This tutorial is downloadable as a PDF file, 3D Slicer Tutorial.pdf or can be looked through in image/slide format here in the blog 3D Slicer Tutorial.pdf
  3. 4 likes
    Here is a tutorial for the Grayscale Model Maker in the free program Slicer, specifically for modeling pubic bones since they are used in anthropology for age and sex estimation. The Grayscale Model Maker is very quick and easy! And I can't stand the "flashing" in the Editor. For this example, I am using a scan from TCIA, specifically from the CT Lymph Node collection. Slicer Functions used: Load Data/Load DICOM Volume Rendering Crop Volume Grayscale Model Maker Save Load a DICOM directory or .nrrd file. Hit Ok. Make sure your volume loads into the red, yellow, and green views. Select Volume Rendering from the drop-down. Select a bone preset, such as CT-AAA. Then click on the eye next to "Volume." ...Give it a minute... Use the centering button in the top left of the 3D window to center the volume if needed. Since we only want the pubic bones, we will use the ROI box and Crop Volume tools to isolate that area. To crop the volume check the "Enable" box next to "Crop" and click on the eye next to "Display ROI" to open it. A box appears in all 4 windows. The spheres can be grabbed and dragged in any view to adjust the size of the box. The 3D view is pretty handy for this so you can rotate the model around to get the area you want. The model itself doesn't have to be perfectly symmetrical because you can always edit it later. Once you like the ROI, we can crop the volume. To crop the volume, go to the drop-down in the top toolbar, select "All Modules" and navigate to "Crop Volume." Once the Crop Volume workspace opens, just hit the big Crop button and wait. You won't see a change in the 3D window, but you will see your slice views adjust to the cropped area. At this point, you can Save your subvolume that you worked so hard to isolate in case your software crashes! Select the Save button from the top left of the toolbar and select the .nrrd with "subvolume" in the file name to save. Now we will use the All Modules dropdown to open the Grayscale Model Maker. If you want to clear the 3D window of the volume rendering and ROI box, you can just go back to Volume Rendering, uncheck the Enable box and close the eyes for the Volume and ROI. When using the Grayscale Model Maker, the only tricky thing here is to select your "subvolume" from the "Input Volume" list, otherwise your original uncropped volume will be used. Click on the "Output Geometry" box and select "Create a new Model as..." and type in a name for your model. Now move down to "Grayscale Model Maker Parameters" in the workspace. I like to enter the same name for my Output Geometry into the "Model Name" field. Enter a threshold value: 200 works well for bone, but for lower density bone, you might need to adjust it down. Since the Grayscale Model Maker is so fast, I usually start with 200 and make additional models at lower values to see which works best for the current volume. ***Here is where I adjust settings for pubic bones in order to retain the irregular surfaces of the symphyseal faces.***The default values for the Smoothing and Decimate parameters work well for other bones, but for the pubic symphyses, they tend to smooth out all the relevant features, so I slide them both all the way down. Then hit Apply and wait for the model to appear in the 3D window (it will be gray). You can see from the image above that my model is gray, but still has the beige from the Volume Render on it since I didn't close the Volume Rendering. If for some reason you don't see your model: 1) check your Input Volume to make sure your subvolume is selected, 2) click on that tiny centering button at the top left of your 3D window, or 3) go to the main dropdown and go to "Models." If the model actually generated, it will be there with the name you specified, but sometimes the eye will be closed so just open it to look at your model. Now we an save your subvolume and model using the Save button in the top left of the main toolbar. You can uncheck all the other options and just save the subvolume .nrrd and adjust the file type of your model to .stl. Click on "Change Directory" to specify where you want to save your files and Save! This model still needs some editing to be printable, so stay tuned for Pt. 2 where I will discuss functions in Meshlab and Meshmixer. Thanks for reading and please comment if you have any issues with these steps!
  4. 4 likes
    Here is another good case worth sharing: The patient is suffering from a mass in mandible, which is extended into the ramus and mandibular condyle. The mass has perforated the bone and in CT data, air is seen in the ramus. The left mandible is the pathologic and study model. The right one, is made with a technique called "Mirroring". This is a pretty useful technique to produce a rather normal anatomy, so the surgeon will pre-bend the surgical plate on the mirrored model, so after they have resected half of the mandible, they don't have to do the time-consuming plate bending while on the operating table. Our colleagues have reported that this method reduces the time of the surgery up to 2 hours! Please let me know what you think.
  5. 3 likes
    Hello and welcome back. Once again, I am Dr. Mike, board-certified radiologist and 3D printing enthusiast. Today I'm going to show you how to correct severe mesh defects in a bone model generated from a CT scan. This will be in preparation for 3D printing. I'll be using the free software programs Blender and Meshmixer. In my last medical 3d printing video tutorial, I showed you how to remove extraneous mesh within the medullary cavity of a bone. That technique is best used when mesh defects are limited. In instances where mesh defects in a bony model are severe and extensive, a different approach is needed. In this video, I'll show you how to correct extensive mesh errors in bony anatomical models using Blender and Meshmixer. This assumes that you know how to generate a basic STL file from a CT scan. There are a variety of commercial and freeware products that allow you to do this, on a variety of platforms. If you don't yet know how to do this, stay tuned, as I have a series of tutorials planned which will show you how to do this on a variety of operating systems and budgets. If you wish to follow along with this tutorial, you can download the free tutorial file pack by clicking this link. This is highly recommended, as the files allow you to follow along with the tutorial, which will make learning easier. Included is the STL file used in this tutorial. Also, a powerful Blender script is included which will enable you to easily and efficiently prepare your own bone models for 3D printing. It's a real timesaver. If you haven't registered at Embodi3D.com, registration is free and only takes a moment. DOWNLOAD THE ACCOMPANYING FILE PACK. CLICK HERE. You can watch the video tutorial for a quick overview, or read this article for a detailed description. Initial analysis using Meshmixer Let's take a look at an STL file of a talus fracture in the ankle. This 3D model is from a real patient who suffered a fracture of the talus. The talus is the bone in the ankle that the tibia, or shinbone, sits on. This STL file is included in the file pack. Let's open this file in Meshmixer (Figure 1). Meshmixer is free software published by Autodesk, a leading maker of engineering software. If you don't have Meshmixer, you can go to Meshmixer.com and download it for free. Figure 1 Once you have the file open in Meshmixer, click on the Analysis button and select Inspector. The inspector shows all the errors in this mesh. Blue parts represent holes in the mesh. Red parts show areas where the mesh is non-manifold. Magenta parts show disconnected components. As you can see, there are a lot of problems with this mesh, and it is not suitable for 3D printing in its current state (Figure 2). Figure 2 Meshmixer has a feature to automatically repair these mesh defects. However, there are so many problems with this mesh that the auto repair function fails. Click on the Auto Repair All button. Meshmixer has tried to repair these mesh defects, and has successfully reduced the number of defects. However, it is also introduced gaping holes in the model. Entire bones are missing (Figure 3). This clearly isn't the desired outcome. Figure 3 Opening the STL file in Blender The solution to this problem can be found with Blender. Blender is a free, open-source software package that is primarily designed for animation. It is so feature-rich however, that it can be used for a variety of different purposes, and increasingly is being used for tasks related to 3D printing. If you don't have Blender, you can download it from blender.org. At the time of this writing, the current version is 2.73 a. Open up Blender. Go ahead and delete the default cube shown in the middle of the screen (Figure 4) by right clicking it and hitting the "X" key followed by the "D" key. If you are new to Blender, you'll soon learn that much of what you can do with Blender can be done with keyboard shortcuts. This can be daunting to learn for beginners, but makes use of Blender very efficient for heavy users. Figure 4 Next open the STL file in Blender. Go to the File menu in the upper left, select Import, and select "Stl (.stl)." Then, navigate to the folder for the tutorial files and select the "ankle - talus fracture.stl" file. You probably don't see anything, as is shown in Figure 5. To understand how this happens, you need to know a little bit about how Blender measures distances. Blender uses an arbitrary measure of distance called a "blender unit." One blender unit is equivalent to one of the little squares seen in the viewport. However, in real life distances are measured in real units, such as feet, inches, centimeters, and millimeters. Most STL files that are generated from medical imaging data have default unit of measurement of millimeters. When Blender imports the file it converts the millimeter units to blender units. Since our imported model is the size of human foot, measuring 240 mm or so, the model will be 240 blender units, or 240 of those little squares, in length. We can't see it because the model is too big! Our viewport is zoomed into much! Zoom out using the mouse wheel way, way back until you can see the model as shown in Figure 6. Figure 5: Where is the model? Figure 6: There it is! Correcting the Object Origin You will notice that the origin of the ankle object, as shown by the red blue and green axes (Figure 6), is actually outside of object itself. Left uncorrected, this can be a really annoying issue. When you rotate or pan around the object, you will rotate or pan around these three axes, instead of the ankle object itself. Fortunately, correcting this takes only a moment. In the lower left-hand part of the window select the Object menu. Be sure that you have the ankle object selected first. Then choose Transform, Geometry to Origin. The ankle object is then moved to the red blue and green axes. With the object origin now in the center of the mesh, the mesh will be much easier to work with. Figure 7: The ankle mesh and object origin are now aligned. Inspect the ankle mesh If you look closely at the ankle mesh you can see immediately that it has a lot of problems. In the solid shader mode, the bones look very faceted. The polygons are large, giving the bones a unnatural appearance (Figure 8). Don't worry, will fix this. If you turn on wireframe mode by hitting the "Z" key you can see that there is a lot of extraneous mesh within the bones that represents unwanted mesh from the medullary cavities of these bones (Figure 9). Furthermore, if you check for non-manifold mesh by holding control-shift-alt-M, you'll see that there are innumerable non-manifold mesh defects (Figure 10). Figure 8: Note the very faceted appearance of the bones. Figure 9: There is a significant amount of unneeded and extraneous mesh, particularly within the medullary cavities of the bones. Figure 10: Non-manifold mesh defects. If you are unfamiliar with the term "non-manifold," let me take a moment to explain. A mesh is simply a surface. It is infinitely thin. If the mesh is continuous and unbroken, and has a contained volume within it, then the mesh can be considered to represent something solid. In this case, the mesh surface represents the interface between the inside of the object and the outside of the object, such as the sphere shown in Figure 11. An object like this is considered to be "manifold," or watertight. It represents a solid that can really exist in the physical world, and can thus be 3D printed. Figure 11 If however, I cut a hole in the sphere, as shown in Figure 12, then there is a gap in the mesh. A 3D printer won't know what to do with this. Is this supposed to be solid like a ball, or hollow like a cup? If it is supposed to be like a cup, how thick are the walls supposed to be? The walls in this mesh are infinitesimally thin, so what is the correct thickness? This mesh is not watertight - that is, should water be placed in the structure it would leak out. The mesh is non-manifold. It cannot be 3D printed. If we use the control-shift-alt-M sequence to highlight non-manifold mesh, as shown in Figure 13, we can see that Blender correctly identifies the edge of the hole as having non-manifold mesh. Figure 12 Figure 13 Closing major holes manually in Blender In this particular mesh, there are many, many small mesh errors and two very large ones. The distal tibia and fibula bones have been cut off by the CT scanner, leaving gaping holes in the mesh as shown in Figure 14. Fixing these manually will only take a moment and make things easier down the road, so let's take care of that now. Enter Edit mode by hitting the Tab key, or clicking it in the Mode menu. If you hit control-shift-alt-M to select non-manifold edges, you can clearly see that these bone cuts are a problem as shown in Figure 15. Figure 14 Figure 15 Go to Vertex selection mode by clicking the vertex button or hitting control-tab-1 on the keyboard as shown in Figure 16. Select one of the vertices from the medullary portion of the tibia bone as shown in Figure 17. This mesh represents the medullary cavity of the tibia bone, and is not connected to the rest of the mesh. Hit control-L to select all contiguous vertices (Figure 18). All the unwanted medullary cavity mesh should now be highlighted. Delete this by hitting the "X" key followed by the "V" key, or by hitting the delete and selecting "vertices." There is another small bit of medullary cavity mesh at the edge of the tibia cut. Perform the same routine and delete this as well. Figure 16 Figure 17 Figure 18 Next we will direct our attention to the unwanted medullary mesh of the thinner fibula bone. Click on a vertex in the fibula medullary mesh and hit control L. You will note that the entire mesh is highlighted as shown in Figure 19. This indicates that the medullary mesh is connected to the rest of the mesh in some way. We don't need to manually delete all of the medullary mesh. We just need to get it away from the edge where we will create a new face to close the bone edges. Go to Edge selection mode by hitting control-tab-2 or clicking the edge selection button as shown in Figure 20. Hit the "A" key to unselect everything. Then, click on a single edge along the unwanted medullary mesh, as shown in Figure 21. Figure 19 Figure 20 Figure 21 Next we will by holding down the alt key and right clicking on the edge again. Blender should select the loop around the entire edge as shown in Figure 22. We will now expand the selection by holding down the control tab and hitting the plus key on the number pad. Hit the plus key three times. Your selection should now look like that in Figure 23. Delete the highlighted mesh by hitting the "X" and "V" keys, or hitting the delete key and selecting vertices. Figure 22 Figure 23 Next we are going to close the holes by holding down the alt key and right clicking along the edge of the cut line of the fibula. An entire loop should be selected as shown in Figure 24. Create a face by hitting the "F" key. Convert to triangles by hitting Control-T. The end of the fibula should be closed, as shown in Figure 25. Repeat the same for the open edge of the tibia bone. Afterwards the mesh should look as it does and Figure 26. Figure 24 Figure 25 Figure 26 Creating a Shell of the model using the Shrinkwrap and Remesh modifiers in Blender So how will it ever be possible to correct the hundreds and hundreds of mesh errors in the ankle model? This is the million-dollar question. A mesh of this complexity often cannot be fixed using automated mesh correction software, as we saw with Meshmixer. Correcting this many errors manually is a time-consuming and tedious process. I've spent hundreds of hours correcting mesh errors like this one by one. But, after years of creating 3D printable anatomical models, I've developed a technique to fix these mesh errors in only a few minutes. The secret is this: You don't fix the mesh errors. Leave them alone. You create a new mesh to replace them! Let's start by creating a sphere. If you are in Edit mode, exit that by hitting the Tab key. If you are still in wireframe viewport mode, hit the "Z" key to return to solid viewport shading. In the lower left-hand side of the window, hit the Add menu. Select Mesh, UV sphere and add a sphere. An "Add UV Sphere" panel will show up on the left side of your screen as shown in Figure 27. We want the sphere to have lots of detail. Under Segments enter 256. Under Rings, enter 128. The default size of the sphere is only one blender unit (1 mm) in size. This is too small, we want the thing to be huge. Enter 1000 for size. At this point you should have a very large sphere surrounding your entire scene. Believe it or not, this sphere will eventually be your new ankle object. Let's go ahead and rename it "Ankle skin" as shown in Figure 29. Figure 27: Add a UV sphere Figure 28: Configure the sphere. Segments 256, rings 128, size 1000 Figure 29: Rename the sphere to "Ankle skin" Applying the Shrinkwrap Modifier Select the "Ankle skin" object. Click on the Modifiers tab, it looks like a small wrench (Figure 30). From the Ad Modifier drop-down menu, select the Shrinkwrap item. Specify the Ankle object as "the target. Set off set to 0.5. Check the" Keep Above Surface" box. Your sphere will have shrunken down to envelop the ankle, as shown in Figure 30. Apply the modifier by hitting the "Apply" button. At this point you're thinking that your Ankle skin object hardly looks like an ankle, and you're right. If you try to apply the shrinkwrap modifier again, you won't get any change in the mesh. Blender has shrunken the sphere as best it can given the limited geometry of the sphere. To go further we need to change the geometry a bit, which is where the Remesh modifier comes in. Figure 30: The Shrinkwrap modifier Applying the Remesh Modifier Next go to Add Modifier again, and select Remesh. Set Mode to Smooth, Octree Depth = 8, and uncheck Remove Disconnected Pieces. By now you should have something that looks like Figure 31. Apply the modifier by clicking the Apply button. Figure 31: The Remesh modifier Apply the Shrinkwrap Modifier again Apply the shrinkwrap modifier again, using the same parameters as before. Your Ankle skin object should look like Figure 32. Now we are getting somewhere! There is still a long way to go, but the mesh somewhat resembles the bones of the foot. By repeatedly applying the Shrinkwrap and Remesh modifiers the Ankle skin object, which was originally a sphere, will slowly approximate the surface of the error-filled original ankle mesh. Because of the original skin was a sphere, and hence manifold, as it is shrink-wrapped around the ankle mesh it will preserve (for the most part) it's mesh integrity. There will be no unnecessary internal geometry. Any holes or other defects in the original mesh will be covered. Unfortunately, repeatedly applying the shrinkwrap and remesh modifier again and again is somewhat tedious (although not as tedious as manually correcting all the errors in the original mesh). Fortunately, we can automate this process using Python scripting. This allows us to create a new mesh in a matter of minutes. Figure 32 Automating the Shrinkwrap Process using Python Scripting For those of you less familiar with Blender's more advanced features, you may be surprised to learn that it is fully scriptable. That means that you can program it to perform tasks repeatedly using a Python script. In this case we want to repeatedly execute shrinkwrap and remesh modifiers on our ankle skin object. With each iteration the skin will more closely approximate the surface of the original mesh. If you are familiar with Python scripting, you can write a script yourself to call the necessary modifiers and specify the necessary variables. To make things easier for you, I have written a Python script for you. It is included in the free tutorial file pack. Change the bottom window to the text editor. View button in the bottom left-hand corner as shown in Figure 33. Select Text Editor. Click on the "Open" button and navigate to the folder with the tutorial file pack files as shown in Figure 34. Double-click on the "shrinkwrap loop.txt" file as shown in Figure 35. Figure 33: Select the text editor Figure 34: Click on the Open button Figure 35: Open the "shrinkwrap loop.txt" file The script file should now open in the text editor window. Adjust the target_object variable to be the target you want your skin wrapped around, in this case the "Ankle - Talus Fracture" object. Leave the shrinkwrap_offset variable at 0.5 for now. You can specify how many shrinkwrap-remesh iterations you want to run. For now leave it at 20. Click the "Run Script" button as shown in Figure 36. The script will now run, and it will apply the shrinkwrap-remesh modifiers 20 times. On my machine it takes about one minute for the script to execute. Figure 36 At this point you'll notice that the ankle skin object very closely approximates the original ankle object, as shown in Figure 37. Run the script again using the same settings. At this point the mesh is really looking pretty good. Let's run the script a final time with the smaller offset to more closely approximate the real bones. Set the shrinkwrap_offset variable to 0.3 and run the script again reducing iterations to 10. After completion the mesh should appear as it does in Figure 38. If you compare our new skin mesh as shown in Figure 39 (left) to the original ankle object in Figure 39 (right) you can see that our new skin is actually much more realistic than the original mesh. The highly faceted appearance of the original mesh has been replaced by a smoothed appearance of our shrink-wrapped skin. Furthermore, whereas the original mesh actually had separate bones that were disconnected, the new, shrink-wrapped mesh is a single interconnected object. From a 3D printing standpoint this is much better as the ankle bones will print together as a single unit Figure 37 Figure 38 Figure 39: Comparison of original plus new shrink-wrapped mesh. Finalizing the Ankle Model for 3D printing using Meshmixer. Select the new ankle object. Export the object to the STL file format. From the file menu select Export and then "Stl (.stl)." Let's call the file "ankle corrected.STL." Open the new STL file in Meshmixer. You will notice that Meshmixer immediately identifies some mesh errors as shown in Figure 40. This is because the Remesh modifier in Blender occasionally introduces non-manifold mesh defects. You will note however that the number of defect is significantly less than our original model which was shown in Figure 1. With this smaller number of errors, Meshmixer can fix them automatically. Go to the Analysis button and select Inspector. Meshmixer will highlight the individual mesh defects, as shown in Figure 41. Click on the "Auto Repair All" button. Meshmixer will then automatically repair the mesh defects. The result is shown in Figure 42. Figure 40 Figure 41: Meshmixer inspector Figure 42: Corrected mesh The mesh looks great, and is ready for 3D printing! Export the STL file by going to the File menu in Meshmixer and selecting Export. Save the file as "ankle final result.STL". Please share with the community. If you have found this tutorial helpful and are actively creating 3D printable anatomic models, please consider sharing your work with the Embodi3D community. You can share your models in the File Vault. If you have comments or advice, you can share your expertise in the Forums. If you are interested in blogging about your adventures in medical 3D printing, contact me or one of the administrators and we can set up blogging on your Embodi3D user account. If you wish to hire someone to help you with your anatomical 3D printing project, you can place an ad for free in the Services Needed Forum, If you are doing your own anatomical 3D printing and are willing to help others, list your services for free in the Services Offered Forum. This is a community. We are all helping each other. Please consider giving back if you can. Have fun 3D printing!
  6. 3 likes
    So I have seen some questions here on embodi3D asking how to work with MRI data. I believe the main issue to be with attempting to segment the data using a threshold method. The democratiz3D feature of the website simplifies the segmentation process but as far as I can tell relies on thresholding which can work somewhat well for CT scans but for MRI is almost certain to fail. Using 3DSlicer I show the advantage of using a region growing method (FastGrowCut) vs threshold. The scan I am using is of a middle aged woman's foot available here The scan was optimized for segmenting bone and was performed on a 1.5T scanner. While a patient doesn't really have control of scan settings if you are a physician or researcher who does; picking the right settings is critical. Some of these different settings can be found on one of Dr. Mike's blog entries. For comparison purposes I first showed the kind of results achievable when segmenting an MRI using thresholds. With the goal of separating the bones out the result is obviously pretty worthless. To get the bones out of that resultant clump would take a ridiculous amount of effort in blender or similar software: If you read a previous blog entry of mine on using a region growing method I really don't like using thresholding for segmenting anatomy. So once again using a region growing method (FastGrowCut in this case) allows decent results even from an MRI scan. Now this was a relatively quick and rough segmentation of just the hindfoot but already it is much closer to having bones that could be printed. A further step of label map smoothing can further improve the rough results. The above shows just the calcaneous volume smoothed with its associated surface generated. Now I had done a more proper segmentation of this foot in the past where I spent more time to get the below result If the volume above is smoothed (in my case I used some of my matlab code) I can get the below result. Which looks much better. Segmenting a CT scan will still give better results for bone as the cortical bone doesn't show up well in MRI's (why the metatarsals and phalanges get a bit skinny), but CT scans are not always an option. So if you have been trying to segment an MRI scan and only get a messy clump I would encourage you to try a method a bit more modern than thresholding. However, keep in mind there are limits to what can be done with bad data. If the image is really noisy, has large voxels, or is optimized for the wrong type of anatomy there may be no way to get the results you want.
  7. 3 likes
    Hello My recent anatomy projects forced me to start importing my 3d models into 3d pdf documents. So I'll share with you some of my findings. The positive things about 3d pdf's are: 1. You can import a big sized 3d model and compress it into a small 3d pdf. 40 Mb stl model is converted into 750 Kb pdf. 2. You can run the 3d pdf on every computer with the recent versions of Adobe Acrobat Reader. Which means literally EVERY computer. 3. You can rotate, pan, zoom in and zoom out 3d models in the 3d pdf. You can add some simple animations like spinning, sequence animations and explosion of multi component models. 4. You can add colors to the models and to create a 3d scene. 5. You can upload it on a website and it can be viewed in the browser (if Adobe Acrobat Reader is installed). The negative things are: 1. Adobe Reader is a buggy 3d viewer. If you import a big model (bigger than 50 Mb) and your computer is business class (core I3 or I5, 4 Gb ram, integrated video card), you'll experience some nasty lag and the animation will look terrible. On the same computer regular 3d viewer will do the trick much better. 2. You can experience some difficulties with multi component models. During the rotation, some of the components will disappear, others will change their color. Also the model navigation toolbar is somewhat hard to control. 3. The transparent and wireframe polygon are not as good as in the regular 3d viewers. The conclusion: If you want to demonstrate your models to a large audience, to sent it via email and to observe them on every computer, 3d pdf is your format. For a presentation it's better to use a regular 3d viewer, even the portable ones will do the trick. But if the performance is not the goal, 3d pdf's are a good alternative. Here is a model of atlas and axis as 3d pfg: https://www.dropbox.com/s/2gm7occq5ur50um/vertebra.pdf?dl=0 Best regards, Peter
  8. 3 likes
    lillux

    Mandibola

    Version 1.0.0

    68 downloads

    This is a model of a woman's mandible. The TC showed two bone's included 3rd molars (wisdom teeth)

    Free

  9. 3 likes
    This is a time of rapid growth in medical 3D printing. The technology allows us to take an individual patient’s scan information and create physical models, which can be used in any number of clinical applications. The industry standard DICOM image files from CT and MRI scanners can be converted into 3D files, such as STL (for stereolithography) files. These digital models can then be uploaded to a 3D printing service bureau or printed on one of the currently available professional grade printers.The democratization of desktop 3D printers, however, now allows almost anyone with a serious interest in the technology to print models in their own office/workshop. These can be used for educational purposes and for prototyping, and represent an excellent entrée into the technology. Recently, I started printing 3D models of some of my own patient’s scans using a consumer grade desktop printer. The patient’s CTs were acquired on our Toshiba Aquillion 64 Slice CT scanner using our standard acquisition protocols. The DICOM volume data was then burned to a CD for processing. For my initial test prints, I used the Materialise Mimics and 3-matic software under their 30-day free trial period. The images from the appropriate volume were imported into the Mimics software. Thresholding is then performed to isolate the tissues in question, based on its Hounsfield units, a measurement of X-ray density. The particular anatomy of interest is then selected using “region growing” tools and a 3D model is generated. The model is then “wrapped”, to account for the individual CT slices, and to smooth any gaps in the 3D mesh. Choosing the degree of wrapping is where experience comes into play. Too little wrapping can cause gaps to be present on your final models. Too much, and detail can be lost. The 3D model is then exported into the 3-matic program for “local smoothing” of the model. The digital model is then hollowed, depending on the structure and its use. You then export it as a binary STL file. In all of the steps above, clinical knowledge of the anatomy is extremely helpful in creating the most accurate models possible. Understanding how the models will be used informs your decisions in their creation. The STL file is then imported into a slicing software to create the G-code files that instruct the printer how to actually create the physical model. I used the open source Cura software for the generation of the G-code for the printer. An image of the 3D model is seen superimposed in a representation of the build plate of the particular printer, in my case the Ultimaker 2 (Ultimaker B.V.). The model can be rotated to optimize the printing process. The highest resolution of current 3D prints from fused filament printers is in the z-direction: from the bottom on the build plate to the top of the object. The degree of overhang must also be taken into account. Since the filament cannot be deposited in thin air, the slicing software creates a scaffold to support the overhanging material. Keep in mind; this support structure must be physically removed in post-processing. The slicing software also creates a thin base layer of the material (called a brim or raft) that is deposited around the object to facilitate print adherence to the print platform. The generated G-code is saved to an SD card, which is then placed into the printer. In some cases, the files can be transferred wirelessly. I used 2.85 mm PLA filament to create the printed models. PLA is polylactic acid, a biodegradable material derived from cornstarch. PLA based material has been used in orthopedics for sutures, controlled release systems, scaffolding for cartilage regeneration, and fixation screws. The print time takes several hours, depending on the size and complexity of the model, as well as the amount of support structure used. Through trial and error, I found that careful positioning of the 3D model on the virtual build plate can potentially shorten the length of printing time. A full-scale hollow abdominal aortic aneurysm model took about 9 hours to print, while a full-scale scapula took 13 hours. A life-size pediatric skull will take approximately 23 hours to print! The use of 3D printing in medicine presents enormous potential. Exponential development of many new applications will occur if researchers, students and clinicians have access to small-scale 3D printers for prototyping new devices and procedures. The future is only limited by the imagination. A method of reimbursement wouldn’t hurt either. I would like to thank Frank Rybicki, MD, Professor and Chair of Radiology, University of Ottawa, and his team from the Applied Imaging Science Laboratory at Brigham and Women's Hospital for their great 3D Printing Hands-on courses at RSNA 2014. Copyright ©2015 Eric M. Baumel, MD
  10. 3 likes
    Hello everyone We have been working on another interesting case recently, and I thought I would share it with you. The patient had been diagnosed with odontogenic myxoma, and had undergone hemimaxillectomy. Due to loss of literally half the face, the patient is seeking a solution to help bring back his facial profile. We designed a prosthesis, using mirroring techniques, and the result turned out to be like this. The next step is to determine how to make the actual prosthesis.
  11. 3 likes
    This is actually very amazing, and it is really doable with some practice and mastery of the softwares. We have printed numerous models, from crania-maxillofacials to vascular malformations, and also some interesting craniosynostosis cases. It is getting pretty common in the hospital.
  12. 3 likes
    descobar3d

    From Dicom to .STL

    There are several options for clinicians to use when converting a patients .dicom data into a 3D printed model. For our 3D Printing Program I use the Mimics Innovation Suite made by Materialise. The software is available for computers running Windows. The software receives regular updates to improve functionality and increase the efficiency and quality of the .dicom to 3D print workflow. It is capable of converting CT, MRI, and 3D ultrasound images into 3D models that are ready for the 3D printer. There are many things that I enjoy when using this software, including:​ Ease of use for beginner users Fast processing time, <30 minutes for many projects Many different features available To give a demonstration on how the software is easy to use, I will use a CT scan of my own head. After the files are loaded, the software detects the appropriate scan studies that are present. You are able to load multiple scans into a single project. Apply thresholding: Mimics has built in presets for CT bone, soft-tissue, etc. I selected the preset for CT bone. After the thresholding is applied a new Mask is created. The mask shows only bone in the scan. Edit mask in 3D: Before i create a new 3D mask, i can edit my current mask to make changes such as removing unwanted pieces and cropping the unwanted areas before moving forward. Region Growing: In order to remove floating voxels and detach unwanted bony anatomy, the Region Growing tool is applied. It will preserve only the bone that is desired in the mask. Calculate 3D from Mask: Once the mask is edited the way you need, you will Calculate 3D object from the Mask. The 3D object can further exported into 3Matic for additional changes or exported as an .stl file for 3D printing. Export to 3Matic: I would demonstrate the tools for cleaning and preparing the part for printingWrap to fill small holes Smoothing to smooth the surfaces Quick label to apply a label to the part Fix wizard to make sure the part is watertight for printing Export 3D PDF as a communication tool [*]Copy-Paste the completed file from 3-matic back to Mimics. Show the contours of the 3D model on the original images. Point out the importance of verifying the accuracy of the part prior to exporting STL. Conclusion: When evaluating software for printing 3D models from patient scans, look at features, cost, compatibility, and ease of use. Ask for a demonstration and trial before purchasing. There are different options for software, it is important to look for one that works with your workflow. Want to learn more? Contact Me David@3dAdvantage.org Visit my site 3DAdvantage
  13. 3 likes
    A few years ago, a friend and colleague of mine was working in the Hell Creek formation of Montana and collected a small fossil jaw fragment. Due to the tiny size and incomplete nature of the bone, along with the need to continue work during the limited time available, he wrapped up the specimen, tentatively labeled it as a crocodilian jaw and moved on. Later, another friend of mine was evaluating this specimen in the museum collection (Museum of the Rockies) and concluded that the jaw was not that of a crocodilian, but rather of a tyrannosaur. Named "Chomper", this specimen generated a lot of excitement, due to the paucity of baby/juvenile T. rex material known and the strong current interest in dinosaur ontogeny. The specimen was sent to Dr. Larry Whitmer, who brought it into the digital domain to realize a very interesting new exhibit feature. After CT-scanning the jaw, Larry and his cohorts digitally created the rest of the skull. To do this, they used scans of another (but substantially larger) juvenile T. rex skull known as "Jane". Using other existing tyrannosaurid fossils for reference, they edited the Jane skull model to shrink it down to the correct proportions needed to fit the tiny jaw bone. Simply scaling down an adult T. rex skull wouldn't do, since growth in the skull is allometric (different areas grow at different times/rates). The resulting skull model was then printed on an Objet printer (a supremely nice machine) and is now being prepared to go on exhibit at the Museum of the Rockies. You can see a nice chronicle of the process on the WhitmerLab Facebook page here: https://www.facebook.com/witmerlab As someone who has spent a lot of time manually sculpting/reconstructing dinosaur skulls by hand, I can appreciate the mix of artistic sensibility and anatomical knowledge needed to do this kind of reconstruction, and I must say that the results of the WhitmerLab crew are fantastic, and this technology allows for many amazing possibilities. Michael
  14. 3 likes
    We are happy to receive recognition for being a top influencer in 3D printing. Thanks to all the members of this community who are helping us bring the benefits of biomedical 3D printing to the world! The Management.
  15. 3 likes
    Dr. Mike, here's a blog post I did on the paper printing: https://zenstorming.wordpress.com/2015/03/04/printing-with-paper-the-21st-century-way/ There are links to pdf's in the post with one a case study from Louvain. Enjoy!
  16. 3 likes
    I totally agree with mplishka. The two main firms that do surgical planning models are Medical Modeling (now owned by 3D systems) and Materialise. Reimbursement is a major obstacle. Right now, there is no way to get paid for this, so anything you do clinically must be paid for by the hospital or research grant, or is on your own dime. I just returned from Arizona after attending the Mayo Clinic 3D printing in Medical Practice conference and reimbursement was agreed to be a major obstacle. This is why the very limited 3D printing for surgical planning is mainly being done at wealthy institutions that can absorb the cost (like Mayo). FYI, here are a few of the models that were on display at the conference from both Medical Modeling and Materialise. protohex, I agree that there is a market for a more diverse set of medical 3D printing services, with different price points, materials, turn around times, etc. I've long recognized this. If anybody out there is offering medical 3D printing services (segmentation, design, and printing), please let the community know about your availability by posting in the forums section under services offered. We need more than just two choices!
  17. 3 likes
    3DSystems will do it as will Materialise. There are a couple of other players that their names escape me at the moment, but any 3d printing company can do the printing once they get the STL (heck even individuals with a decent printer with connections can do it!) I've had some in depth discussions with folks from 3DSystems and Materialise and they both point out that it's not about printing per se, it's about workflows. Getting files segmented, cleaned up and then printed in an expeditious manner is the challenge, with emphasis on the 'expeditious' part. Those two companies alone can handle the printing and even the segmentation, but getting their services into hospitals as THE provider is the challenge, especially since there still isn't a reimbursement structure in place for 3d printing. The burden is on the healthcare provider to find a way of getting the prints paid for without losing money.
  18. 2 likes
    Dear all First of all thank you so much Dr Mike for this wonderful website. I am with the University of Michigan and been doing some research on teeth morphology using Micro CTs. I am working mostly with MeVislab frameworks and Mimics. Regarding slicer I would like to ask if it is possible to import TIFF files as slices instead of DICOM files. Each time I try to import data in TIFF my slicer version keeps crashing. Any tips? Best Regards Diogo
  19. 2 likes
    No problem! You need to go to All Modules, then Crop Volume, hit Crop and wait. Then you will see your slice windows change to the area you designated. When you go to Save, you will see that there is a second volume that says "subvolume". This is the cropped volume that you can save as .nrrd. This format can be reopened in Slicer or uploaded to the democratiz3d app to get a printable model.
  20. 2 likes
    I haven't tried importing tiff's but one thing to try would be to use ImageJ to convert a stack of tiffs to an nrrd file for loading in 3DSlicer. Mike (not Dr. Mike;)
  21. 2 likes

    Version 1.0.0

    37 downloads

    This is an anonymized CT scan DICOM dataset to be used for teaching on how to create a 3D printable models.

    Free

  22. 2 likes
    Please note that any references to “Imag3D” in this tutorial has been replaced with “democratiz3D” In this tutorial you will learn how to create multiple 3D printable bone models simultaneously using the free online CT scan to bone STL converter, democratiz3D. We will use the free desktop program Slicer to convert our CT scan in DICOM format to NRRD format. We will also make a small section of the CT scan into its own NRRD file to create a second stand-alone model. The NRRD files will then be uploaded to the free democratiz3D online service to be converted into 3D printable STL models. If you haven't already, please see the tutorial A Ridiculously Easy Way to Convert CT Scans to 3D Printable Bone STL Models for Free in Minutes, which provides a good overview of the democratiz3D service. You should download the file pack that accompanies this tutorial. This contains an anonymized DICOM data set that will allow you to follow along with the tutorial. >>> DOWNLOAD THE TUTORIAL FILE PACK <<< Step 1: Register for an Embodi3D account If you haven't already done so, you'll need to register for an embodi3D account. Registration is free and only takes a minute. Once you are registered you'll receive a confirmatory email that verifies you are the owner of the registered email account. Click the link in the email to activate your account. The democratiz3D service will use this email account to send you notifications when your files are ready for download. Step 2: Create NRRD Files from DICOM with Slicer Open Slicer, which can be downloaded for free from www.slicer.org. Take the folder that contains your DICOM scan files and drag and drop it onto the slicer window, as shown in Figure 1. If you downloaded the tutorial file pack, a complete DICOM data set is included. Click OK when asked to load the study into the DICOM database. Click Copy when asked if you want to copy the images into the local database directory. Remember, this only works with CT scans. MRIs cannot be converted at this time. Figure 1: Dragging and dropping the DICOM folder onto the Slicer application. This will load the CT scan. A NRRD file that encompasses the entire scan can easily be created by clicking the save button at this point. Before we do that however, we are going to create a second NRRD file that only contains the lumbar spine, which will allow us to create a second 3D printable bone model of the lumbar spine. Open the CT scan by clicking on the Show DICOM Browser button, selecting the scan and series within the scan, and clicking the Load button. The CT scan will then load within the multipanel viewer. From the drop-down menu at the top left of the Slicer window, select All Modules and then Crop Volume, as shown in Figure 2. You will now want to create a Region Of Interest (ROI) to encompass the smaller volume we want to make. Turn on the ROI visibility button and then under the Input ROI drop-down menu, select "Create new AnnotationROI," As shown in Figure 3. Figure 2: Choosing the Crop Volume module Figure 3: Turn on ROI visibility and Create a new AnnotationROI under the Input ROI drop-down menu. A small cube will then be displayed in the blue volume window. This represents the sub volume that will be made. In its default position, the cube may not overlay the body, and may need to be dragged downward. Grab a control point on the cube and drag it downward (inferiorly) as shown in Figure 4. Figure 4: Grab the sub volume ROI and drag it downwards until it overlaps with the body. Next, use the control points on the volume box to position the volume box over the portion of the scan you wish to be included in the small 3D printable model, as shown in Figure 5. Figure 5: Adjusting the control points on the crop volume box. Once you have the box position where you want it, initiate the volume crop by clicking the Crop! button, as shown in Figure 6. Figure 6: The Crop! button You have now have two scan volumes that can be 3D printed. The first is the entire scan, and the second is the smaller sub volume that contains only the lumbar spine. We are now going to save those individual volumes as NRRD files. Click the Save button in the upper left-hand corner. In the Save Scene window, uncheck all items that do not have NRRD as the file format, as shown in Figure 7. Only NRRD file should be checked. Be sure to specify the directory that you want each file to be saved in. Figure 7: The Save Scene window Your NRRD files should now be saved in the directory you specified. Step 3: Upload your NRRD files and Convert to STL Files Using the Free democratiz3D Service Launch your web browser and go to www.embodi3d.com. If you haven't already register for a account. Registration is free and only takes a minute. Click on the democratiz3D navigation item and select Launch App, as shown in Figure 8. Figure 8: launching the democratiz3D application. Drag-and-drop both of your NRRD files onto the upload panel. Fill in the required fields, including a title, short description, privacy setting (private versus shared), and license type. You must agree to the terms of use. Please note that even though license type is a required field, it only matters if the file is shared. If you keep the file private and thus not available to other members on the site, they will not see it nor be able to download it. Be sure to turn on the democratiz3D Processing slider! If you don't turn this on your file will not be processed but will just be saved in your account on the website. It should be green when turned on. Once you turn on democratiz3D Processing, you'll be presented with some basic processing options, as shown in Figure 9. Leave the default operation as "CT NRRD to Bone STL," which is the operation that creates a basic bone model from a CT scan in NRRD format. Threshold is the Hounsfield attenuation to use for selecting the bones. The default value of 150 is good for most applications, but if you have a specialized model you wish to create, you can adjust this value. Quality denotes the number of polygons in your output file. High-quality may take longer to process and produce larger files. These are more appropriate for very large or detailed structures, such as an entire spinal column. Low quality is best for small structures that are geometrically simple, such as a patella. Medium quality is balanced, and is appropriate for most circumstances. Figure 9: The democratiz3D File Processing Parameters. Once you are satisfied with your processing parameters, click submit. Both of your nrrd files will be processed in two separate bone STL files, as shown in Figure 10. The process takes 10 to 20 minutes and you will receive an email notifying you that your files are ready. Please note, the stl processing will finish first followed by the images. Click on the thumbnails for each model to access the file for download or click the title. Figure 10: Two files have been processed simultaneously and are ready for download Step 4: CT scan conversion is complete your STL bone model files are ready for 3D Printing That's it! Both of your bone models are ready for 3D printing. I hope you enjoyed this tutorial. Please use the democratiz3D service and SHARE the files you create with the community by changing their status from private or shared. Thank you very much and happy 3D printing!
  23. 2 likes
    Please note the democratiz3D service was previously named "Imag3D" In this tutorial you will learn how to quickly and easily make 3D printable bone models from medical CT scans using the free online service democratiz3D. The method described here requires no prior knowledge of medical imaging or 3D printing software. Creation of your first model can be completed in as little as 10 minutes. You can download the files used in this tutorial by clicking on this link. You must have a free Embodi3D member account to do so. If you don't have an account, registration is free and takes a minute. It is worth the time to register so you can follow along with the tutorial and use the democratiz3D service. >> DOWNLOAD TUTORIAL FILES AND FOLLOW ALONG << Both video and written tutorials are included in this page. Before we start you'll need to have a copy of a CT scan. If you are interested in 3D printing your own CT scan, you can go to the radiology department of the hospital or clinic that did the scan and ask for the scan to be put on a CD or DVD for you. Figures 1 and 2 show the radiology department at my hospital, called Image Management, and the CDs that they give out. Most radiology departments will have you sign a written release and give you a CD or DVD for free or with a small processing fee. If you are a doctor or other healthcare provider and want to 3D print a model for a patient, the radiology department can also help you. There are multiple online repositories of anonymized CT scans for research that are also available. Figure 1: The radiology department window at my hospital. Figure 2: An example of what a DVD containing a CT scan looks like. This looks like a standard CD or DVD. Step 1: Register for an Embodi3D account If you haven't already done so, you'll need to register for an embodi3d account. Registration is free and only takes a minute. Once you are registered you'll receive a confirmatory email that verifies you are the owner of the registered email account. Click the link in the email to activate your account. The democratiz3D service will use this email account to send you notifications when your files are ready for download. Step 2: Create an NRRD file with Slicer If you haven't already done so, go to slicer.org and download Slicer for your operating system. Slicer is a free software program for medical imaging research. It also has the ability to save medical imaging scans in a variety of formats, which is what we will use it for in this tutorial. Next, launch Slicer. Insert your CD or DVD containing the CT scan into your computer and open the CD with File Explorer or equivalent file browsing application for your operating system. You should find a folder that contains numerous DICOM files in it, as shown in Figure 3. Drag-and-drop the entire DICOM folder onto the Slicer welcome page, as shown in Figure 4. Click OK when asked to load the study into the DICOM database. Click Copy when asked if you want to copy the images into the local database directory. Figure 3: A typical DICOM data set contains numerous individual DICOM files. Figure 4: Dragging and dropping the DICOM folder onto the Slicer application. This will load the CT scan. Once Slicer has finished loading the study, click the save icon in the upper left-hand corner as shown in Figure 5. One of the files in the list will be of type NRRD. make sure that this file is checked and all other files are unchecked. click on the directory button for the NRRD file and select an appropriate directory to save the file. then click Save, as shown in Figure 6. Figure 5: The Save button Figure 6: The Save File box The NRRD file is much better for uploading then DICOM. Instead of having multiple files in a DICOM data set, the NRRD file encapsulates the entire study in a single file. Also, identifiable patient information is removed from the NRRD file. The file is thus anonymized. This is important when sending information over the Internet because we do not want identifiable patient information transmitted. Step 3: Upload the NRRD file to Embodi3D Now go to www.embodi3d.com, click on the democratiz3D navigation menu and select Launch App, as shown in Figure 7. Drag and drop your NRRD file where indicated. While NRRD file is uploading, fill in the "File Name" and "About This File" fields, as shown in Figure 8. Figure 7: Launching the democratiz3D application Figure 8: Uploading the NRRD file and entering basic information To complete basic information about your NRRD file. Do you want it to be private or do you want to share it with the community? Click on the Private File button if the former. If you are planning on sharing it, do you want it to be a free or a paid (licensed) file? Click the appropriate setting. Also select the License Type. If you are keeping the file private, these settings don't matter as the file will remain private. Make sure you accepted the Terms of Use, as shown in Figure 9. Figure 9: Basic information fields about your uploaded NRRD file Next, turn on democratiz3D Processing by selecting the slider under democratiz3D Processing. Make sure the operation CT NRRD to Bone STL is selected. Leave the default threshold of 150 in place. Choose an appropriate quality. Low quality produces small files quickly but the output resolution is low. Medium quality is good for most applications and produces a relatively good file that is not too large. High quality takes the longest to process and produces large output files. Bear in mind that if you upload a low quality NRRD file don't expect the high quality setting to produce a stellar bone model. Medium quality is good enough for most applications. If you wish, you have the option to specify whether you want your output file to be Private or Shared. If you're not sure, click Private. You can always change the visibility of the file later. If you're happy with your settings, click Save & Submit Files. This is shown in Figure 10. Figure 10: Entering the democratiz3D Processing parameters. Step 4: Review Your Completed Bone Model After about 10 to 20 minutes you should receive an email informing you that your file is ready for download. The actual processing time may vary depending on the size and complexity of the file and the load on the processing servers. Click on the link within the email. If you are already on the embodied site, you can access your file by going to your profile. Click your account in the upper right-hand corner and select Profile, as shown in Figure 11. Figure 11: Finding your profile. Your processed file will have the same name as the uploaded NRRD file, except it will end in "– processed". Renders of your new 3D model will be automatically generated within about 6 to 10 minutes. From your new model page you can click "Download this file" to download. If you wish to share your file with the community, you can toggle the privacy setting by clicking Privacy in the lower right-hand corner. You can edit your file or move it from one category to another under the File Actions button on the lower left. These are shown in Figure 12. Figure 12: Downloading, sharing, and editing your new 3D printable model. If you wish to sell your new file, you can change your selling settings under File Actions, Edit Details. Set the file type to be Paid, and specify a price. Please note that your file must be shared in order for other people to see it. This is shown in Figure 13. If you are going to sell your file, be sure you select General Paid File License from the License Type field, or specify your own customized license. For more information about selling files, click here. Figure 13: Making your new file available for sale on the Embodi3D marketplace. That's it! Now you can create your own 3D printable bone models in minutes for free and share or sell them with the click of a button.If you want to download the STL file created in this tutorial, you can download it here. Happy 3D printing!
  24. 2 likes

    Version 1.0.0

    22 downloads

    This 3D printable STL file contains a model of the skull of a edentulous (without teeth) patient was derived from a medical CT scan. This model was created using the Imag3D 3D model creation service 0522c0909

    Free

  25. 2 likes
    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!
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    Hello, Does anyone know how to correct "stretched" sagittal and coronal planes in 3D Slicer? The axial plane is normal. According to the Slicer wiki, i think that using the Orient Scalar Volume may solve this but within the Converters module there is only BSpline to deformation field. There is a parameter set for Create new command line, but that's a bit beyond my skillset. I'll attach a screenshot and if anyone has an easy way to solve this i'd love to hear it. If there's a hard way to solve it i'd love to hear it too but feel free to explain like i'm 5. Slicer wiki page: https://www.slicer.org/wiki/Documentation/4.0/Modules/OrientScalarVolume Currently using Slicer 4.5.0-1 Thanks in advance! Roman
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    I took a look at your models but the privacy setting prevents them from being viewed. I personally find using threshold for segmentation pretty antiquated and use grow/cut for segmentation. This may help for you needs but would be too involved to explain here. I would imagine the issue with the inferior part of the head not having a uniform intensity and giving a rough surface... but I am just guessing
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    Cool article about using Finite Element Analysis to predict bone fractures (I love FEA ). https://www.asme.org/engineering-topics/articles/finite-element-analysis/bone-breaking-predictions-put-to-test-with-fea It's very accurate, so to that end, it might not be necessary to create 3d models if the actual bone can be scanned, digitally modelled and then virtually stressed. What types of fracture studies are you planning (if you can share ;-) ) ? Are you looking from a predictive standpoint or from a pure analysis standpoint; perhaps trying to figure out how to prevent certain fractures based upon certain loadings? I think it would be fascinating to print bone with integrated sensors to understand specific deformations at multiple points. It would not necessarily be essential to fail the bone, just understand how forces are transmitted. Printing with multiple materials would be cool in the future to create the ultimate composite bone model. I can see potential problems with micro-anomalies in the bone, or in any of the constraints. The result would false negative/positive failures. One could also do a hybrid approach. Do FEA and at certain points in the analysis, export the deformed file with colors and print it out. You can take the bone apart and see how it's bending/twisting/etc. and what's happening inside it. Just some thoughts Good luck!
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    Another paid option for video editing and screen capture is Camtasia. The Mac version is $99 and the Windows version is $299.
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    A company in Brazil called Artis Tecnologia has developed medical 3D printing technologies to aid in skull resection surgery. They demonstrated their techniques on a volunteer patient who received surgery for free at the university hospital of the Federal University of São Paulo (UNIFESP). They published an article about it two weeks ago in the International Journal of Computer Assisted Radiology and Surgery. Their technologies allow the removal of a skull tumor and the implantation of a prosthesis in a single surgery. The company works with the doctors to plan the surgery and make the mold for the prosthesis. In this case the company donated the mold and the surgical navigator for the computer assisted surgery (CAS). Planning of the prosthesis Surgical planning First, the doctors take a CT scan of the patient, following a specific protocol so that it is precise enough to make the personalized mold. The scans are imported into the company’s EximiusMed software and which is compatible with the surgical navigator. The company is responsible for deciding on the surgery margin, and providing an image of the prosthesis, which is approved by the surgeon. The planning and production of the mold takes four days. Mold production The personalized mold is made with Magics software from Materialise, a company from Belgium. They make the mold for the prosthesis as well as a model of the bone fault, with submillimeter precision, using a 3D printer from 3D Systems, which uses layer-by-layer manufacturing in layers 0.16 inches thick. It is made from a plaster-like material, and finished with an insulator on the inside and scratch proof finish on the outside. Then, the mold and bone fault are packed in blister packaging, sealed with Tyvek, and sterilized by ethylene oxide, before shipping. Images of the mold Making the prosthesis The prosthesis, made from PMMA during surgery, is created using a hand press as shown in the video. The PMMA in plastic phase undergoes a slight contraction, and using 20% extra PMMA and a press, ensures the correct size for the prosthesis. The extra material drains out of the mold and can be easily removed from the prosthesis. The mold also absorbs heat from the exothermic reaction. It is pressed until polymerization is complete which takes ten to twenty minutes. Finally the prosthesis is washed generously with saline solution. Placing the prosthesis on the skull fault The surgeon decides how to perforate and attach the prosthesis, in this case with titanium clips The clips are used to stabilize the prosthesis but not hold it in place. The prosthesis should overlap the edges of the skull fault as shown in the figure so it does not slip into the cranial cavity. Images after surgery
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    Yes, please. The rendered 3D model (.stl file) should be anonymous, meaning free of any personal identifying information or any headers or metatags from the DICOM data and therefore HIPAA exempt. I agree it is still a good idea and professional courtesy to request permission from the clinician who obtained and supplied the DICOM data to you. If you can upload these anonymous craniofacial .stl files to the marketplace then other members of the community (like myself) can use them for educational projects. Also supplying clinical diagnosis would be very helpful. Thanks!
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    Organ transplantations and surgical reconstructions using autografts and allografts have always been challenging. Apart from the complexity of the procedure, healthcare professionals also have difficulty finding compatible donors. Autografts derived from one part of the body may not fit in completely at the new location causing instability and discomfort. As per the U.S. Department of Health and Human Services, about 22 people die each day due to a shortage of transplantable organs. Creating more awareness about organ donation is only part of the solution. Researchers have to look for other alternatives, and this is where technologies such as three-dimensional medical printing and bioprinting are making an impact. Integrated Tissue-Organ Printing System (ITOP) Millions of dollars are being invested to develop technologies that will help healthcare professionals print muscles, bones and cartilages using a printer and transplant them directly into patients. The ITOP system is a big step in that direction. It was developed by researchers at Wake Forest Institute for Regenerative Medicine. They used a special biodegradable plastic material to form the tissue shape, a water-based gel to contain the cells, and a temporary outer structure to maintain shape during the actual printing process. The scientists extracted a small part of tissue from the human body and allowed its cells to replicate in vitro before placing them in the bioprinter to generate bigger structures. Unlike other 3-D printers, the ITOP system can print large tissues with an internal latticework of valleys that allows the flow nutrients and fluids. As a result, the tissue can survive for months in a nutrient medium prior to implantation. Researchers have used this technology to develop mandible and calvarial bones, cartilages and skeletal muscles. The goal is to create more complex replacement tissues and organs to offset the shortage of transplantable body parts. Polylaprocaptone Bone Scaffolds Researchers at John Hopkins are also developing 3-D printable bone scaffolds that can be placed in the human body. Their ingredients include a biodegradable polyester, known as Polylaprocaptone, and pulverized natural bone material. Polylaprocaptone has already been approved by the Food and Drug Administration (FDA) for other clinical applications. Researchers combined it with natural bone powder and special nutritional broth for cell development. The cells were added to a 3-D printer to generate bone scaffolds, which have been successfully implanted into animal models. Researchers at John Hopkins are now looking for the perfect ratio of Polylaprocaptone and bone powder that will produce consistent results. They will subsequently test their scaffolds in humans as well. More studies are being done as we speak. Many surgeons have also started using 3-D printed tissues and bones to help their patients. In the next few years, this technology will become more accessible, affordable and effective and may change medicine forever. Sources: Photo Credit: Wake Forest Institute for Regenerative Medicine Scientists 3D Print Transplantable Human Bone
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    There are some excellent academic resources that make high quality 3D scans and downloadable 3D printable files available to the public from various museums and academic institutions. One great resource is African Fossils collection at: http://africanfossils.org/search Another online collection is a joint university collection at Morphosource: http://morphosource.org/index.php/Browse/Index We have embarked on an academic project with LSU Medical School Department of Human Anatomy to produce an exhibit of full scale hominin skulls for study in comparative anatomy to the modern Homo sapien skull. I will post pics of the fossils for this exhibit in an album here: http://www.embodi3d.com/gallery/album/34-hominin-fossils/ This is an ongoing project with the ultimate goal of producing 3D printed replicas of approximately one dozen skulls of evolutionary significance.
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    Collegue of mine, who is interventional radiologist, said to me, why would we use 3D printed model of vessels to educate younger collegues, i trained on pigs... enough said. Other collegues, mostly old school doctors, are skeptical like for any other new technology, but most of younger collegues are more open minded, so maybe, there's bright future for 3d printing in medicine And last BIG obstacle, is money, like you said. Healthcare system here in Croatia doesn't pay for 3d printed bone grafts as treatment, so we must pay with our own money, and for most of people that is not an option. I try to explain to them that in the beginning we invest with our money in those procedures, but maybe one day it will be routinely covered by our healthcare system. V. Kopacin
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    If you share your models on Embodi3D's file marketplace, nobody can sell those digital files or models except you, unless you specify otherwise. If you decide to distribute your files for free using one of the Creative Commons licenses, you can choose a "Non Commercial" license. That means that people who download your digital model cannot use it for commercial purposes (i.e. sell it). You can also require that the downloader make no derivatives of your work. In other words they can share it but cannot modify it in any way. Or, you can allow them to modify your file but they are required to share that modified file under the same license terms that you shared it with them. In all cases, downloaders who share your file for commercial or non commercial purposes have to properly attribute you as the original author. You also have the option to sell the file, or more accurately a license to use the file, on the marketplace. You can use your own customized license if you have one or use the General Paid File License that Embodi3D provides. The General license allows buyers to make a single 3D print from your file. If they want to make more they have to buy a license from you for each print. I know that practically this is difficult to enforce, but if somebody flagrantly violates your license, for example mass producing your model in a factory in China, you can go after them for violating the license. You can learn more about selling files here. If you have invested great amounts of time in producing high quality models are aren't ready to part with them for free, selling is a good option, especially for very subspecialized models. Embodi3D has worked really hard to make sure that you can share your 3D printable anatomic files on your terms safely. You have many options, and in all cases ownership and control of the model design resides with the creator, YOU. We want to encourage sharing of files and don't want uncertainty about what downloaders can do with files to be a reason why great files aren't shared. If you have any questions, please ask and thanks in advance for sharing!
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    I've recently discovered two similar peer-reviewed online journals that publish articles related to 3D medical modeling and printing. The first is based out of North America called 3D Printing in Medicine: http://threedmedprint.springeropen.com/articles The second is based out of Australia called Journal of 3D Printing in Medicine: http://www.futuremedicine.com/loi/3dp Let me know if anyone has any feedback about the quality or submission process for papers. Both just started.
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    Hi Amir, Yes we print many different medical 3D models including vascular models, bone models and organ models. For the most part we use the open source software 3D Slicer, Blender, and Meshmixer when on a PC computer. If we are using a Mac we use the same basic workflow but use Osirix instead of 3D Slicer. We have found Formlabs printers to be a good fit for our needs.
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    Hey! I have used many, like Materialise, 3D Slicer and so on. You have to use an array of softwares. And yes! this is one of the many models I have printed. I use a RepRap printer with PLA (1.75 mm), with 0.2 mm layers. This kind of models like the above picture takes about one whole day to print and sometimes you have to start over due to technical errors. Have you printed any models? And what kind of use do you expect from it? Cheers Amir
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    Hi everyone! Thanks to David for the review of the great printers. I would like to suggest RepRap printers as well. They are pretty practical and very cheap, and for places where it might be hard to find commercial printers (like here in Iran), they are definitely an awesome option. We have printed a very large number of models over about a year and they have never let me down. Also, since they are open source, you could customized them any way you like and the parts are available everywhere. Cheers Amir
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    This course starts as a very basic introduction to 3D printing, and follows by some topics about bioprinting. I have gone through about a third of it, but I'm guessing it's a means to get people interested in this field. But we have to see.
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    Here is a preview of some of the models I am preparing for the 2016 Society of Interventional Radiology meeting. Hope to see some of you there!
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    In a UK-first, surgeons at Alder Hey Children’s Hospital successfully used a 3D printed model of a spine to help complete an operation. The procedure was the first time NHS doctors have ever used a 3D printed model in the operating room. The model was used by surgeons on the West Derby hospital’s orthopedic team in their efforts to correct the curved back of an eight-year-old patient. The young girl from Whales suffers from kyphoscoliosis, a complicated congenital spinal problem. The plastic model was made with the help of the patient’s CT scans, which were converted into a 3D printable format. The life-size replica was printed in a plastic so it could be sterilized, and then used in the operating room as a guide for the surgeons performing the operation. An NHS First This case is also the first time that a 3D printed model has been taken into the operating room to be used as a reference tool by NHS doctors. Jai Trivedi, Neil Davidson and Colin Bruce were the surgeons who performed the operation. Trivedi, who was lead surgeon, said on Alder Hey’s blog, “There is no doubt the model made this complex procedure operation much safer as it allowed for accurate pre-operative planning and implementation at surgery. Sterile models that can be held during an operation should prove helpful for other surgeons.” The model was made by the 3D printing firm 3D LifePrints. Their representative Henry Pinchbeck said, “We are delighted to be working with the talented surgical teams at Alder Hey who are leading the way in terms of adoption of innovative practices, such as 3D printing.” A Beneficial Collaboration 3D LifePrints has been working closely with a number of Alder Hey doctors in orthopedics, cardio, craniofacial surgery, radiology and other areas to develop 3D models. Both parties believe the models can assist doctors with complex operations, enable easier communication between doctors and patients, and facilitate learning. The successful surgery comes after a new scientific research center was recently opened next to Alder Hey, one component of £260m invested in future development. The center boasts an innovation hub where doctors and scientists can work on building new healthcare technology, as well as facilities for developing and testing new medicines. The innovation service has the goal of harnessing less widely used technologies in healthcare (including 3D printing and bio-sensors) to develop strategies that improve health outcomes for surgery and critical care treatment. This eight-year-old’s successful surgery is just another one of the many examples of how 3D printing can make medical treatment safer and more effective. Image Credits: Alderhey Liverpool Echo
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    I just finished a 3D print of a rather large AAA. I think it turned out alright. Any thoughts? Anyone else doing work like this?
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    Vlad, Things hit the fan on my end so wasn't able to dig as deeply into this as I wanted to and I still didn't finish the course, but what I did go through was pretty well done, with some provocative chapters contained therein. I was most happy with their use of interesting (and sometimes unfamiliar) case studies that helped drive home the value that 3d printing technologies could have in healthcare. All in all, it's a good foundational (if not basic at times) review of where 3d printing is and where it can go. I'm still able to access the videos and the rest of the course material even though the course is 'over'. I hope to cover the material I missed when I have a free moment. All the best! Mike
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    On my last post I gave an overview of the 3D printers I am currently using in our hospital program. Now I will be explaining the different software I have used from one time to another to go from 3D model to 3D print. The software I cover here is available as a free download or for under $500. 1. TinkerCAD: The first software I used was TinkerCAD. It is a web-based CAD design tool, Simply create a free account and start designing. The layout and menu's are simple and basic enough for beginners to naviagate. It offers many pre-made tools to use from adding letters to adding shapes. For creating designs in TinkerCAD it uses a combination of adding and subtracting shapes or using pre-made designs. The main tools I use are Align, Group, Ruler, and Cylinder. When finished you can download your designs for exporting to a 3D printer or use a 3rd party to print your design for you. For being a entry-level software I still use it to add connections between bones, and for simple movement between parts. Importing .stl files is an important function to use when creating files in other software and wanting to edit in TinkerCAD. Use in Healthcare Applications: Adding custom connections between parts, creating simple frames and supports. Pros: Simple design, easy to use, no software to download, free, always available online from any computer. Cons: Pre-loaded shapes can be limiting for complex parts. Amazing results can be achieved with practice and time. 2. 123D Design: This software is part of the Autodesk family. This a free download, geared more towards users with some knowledge of CAD software. Where TinkerCAD requires the user to use shapes to make designs, in 123D you can create from scratch. This software is ideal for designing prototypes and those wanting to becoming more familiar with CAD software. I use 123D when I need more control than what is offered in TinkerCAD. Use in Healthcare Applications: The software provides more customization than TinkerCAD. It allows for custom-made parts used in Rapid Prototyping Design. Pros: Simple to use, free, great for learning CAD software. Cons: Other software is capable of the same functions. 3. Autodesk Fusion360: I recently started using this software. As our 3D printing program grew I started to receive request to design prototypes based on drawings. Fusion360 has been my software of choice when creating prototypes. The software offers many tools from Sculpting, Combining, Importing Mesh, and Press & Pull, to name a few. I can spend countless post just discussing all the features available in Fusion360, best advice is to go use it. The online support is outstanding. Autodesk really has stood behind this product and helping the community, all my questions were answered within hours (during business hours) and customer support always provided screenshots or videos as well as the written steps. Fusion360 also has a new feature that will export directly to the printing software included or a 3rd party software, such as Preform, Simplify3d, Meshmixer, etc. Use in Healthcare Applications: Designing prototypes, creating designs based off of patient scan data, creating a wide range of models from simple to complex, allows for online collaboration with your team. Pros: Many features available, great online/community support, constant updates to software. Cons: Cost associated with purchasing software (minimal) 4. Meshmixer: Another software from the Autodesk family that I use. This is a very powerful & valuable piece of free software to have when 3D printing. Meshmixer gives you control over many different aspects of your model, including Transform, Plane Cut, Sculpt, Analysis, and adding Supports. The Analysis function provides Slicing of your model, it will correct errors and prepare the model for 3D Printing. Meshmixer allows direct exporting to certain printers (*listed in Meshmixer). Using the Support feature allows you to define how supports will be generated. This software also allows you to add or remove supports that are generated by the software, a very useful feature when printing a patient specific model that is dependent on accuracy. Use in Healthcare Applications: This software is a must-have. I use it to double-check for any slicing errors prior to printing. You can also sculpt organic models from scratch (see uterus) Pros: Free. Many editing options available. Will help ensure more successful prints. Cons: Although there are training guides and a community forum. The software can be overwhelming to a first time user. The best recommendation is to search forums and spend time using the software to become familiar with the available features. Conclusion There are many options available when choosing software to use. It is important to evaluate cost, ease of use, available functions, and capability with the 3D printers you will be using. Evaluate the goals of your 3D Printing Program to choose what combination of software you will need and use. Remember as most of the software featured here is free, spend time working with each one. Links to software websites found Here An added extra. Download a 3D Skull ready for Print Click Here Written by David Escobar Check out my site for more information 3DAdvantage.org Twitter: @descobar3d
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    Fresh off the printer! I use an Ultimaker 2 printer using Colorfab white PLA. The Ultimaker uses Cura software to provide the G code and also will generate the support if needed. I just used the "normal" print settings which gives 100 micron resolution. I reduced the size by 60% and the print time was around 7 hours. I am pretty happy with the print considering this was my first anatomical model. Looking forward to more tutorials!
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    There is a very cool technology printing with regular paper. It can be done in full color and it's much cheaper than other modes of printing and is quick as well. The challenge is that the print volume is the size of the (double) ream of paper. The models can be designed to be glued together if larger models are needed. The models I have seen are always shrunk a little, so this technology may be better for patient education than for surgical planning, but it's still pretty cool. http://mcortechnologies.com/ http://mcortechnologies.com/solutions/medical/ The folks at Mcor (they're a hop skip and jump away from me) have the same problems with other 3d printers, regarding adoption. Reimbursement being the biggie as well.
  49. 2 likes
    I went to the RSNA meeting this year and took the training course in Mimics that Frank Rybicki was giving. It is great software, but very expensive from what I hear from people who have purchased a license. I am working on developing methods of designing 3D printed anatomic models using freeware, and will be publishing a tutorial shortly. Stay tuned. Dr. Mike
  50. 2 likes
    3D printing is now very useful in the field of medical science as many medical researchers are tapping the use of 3D printing technology to streamline different medical procedures. The researchers from the School of Pharmacy and Biomedical Science from the University of Central Lancashire developed 3D printer filament that consists of various drugs. Called the drug polymer filament, this small pill is used in place of conventional thermoplastic filaments like ABS and PLA. The researchers have made this filament using the MakerBot Replicator 3D printer. This means that it will also be possible for those at home to print their own tablet medications and pills. The purpose of this invention is to make it easier for patients to take their medication. Imagine waking up and hitting a button on the computer and after a few minutes, the printer is able to “print” the exact daily dosage of drugs that you need to take? With this invention, it will be more difficult for patients to forget about taking their pills. According to the researchers particularly the main proponent, Dr. Mohammed Albed Alhnan of the UCLan, this technology will also be useful among pharmaceutical companies. Since they can create customized medicine for each patient that they cater. Unfortunately, this invention will not be available until 2019 as scientists perceive that there are several regulatory obstacles that need to be addressed regarding the exact dosage and size of the pills. Nevertheless, this innovation is something that the pharmaceutical industry should be excited about.
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