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Found 218 results

  1. A member recently messaged me with a question about a brain she printed from this file. I as posting the response here in the hope that it will help others in the community. QUESTION "I came across your 3D printable human brain model and was able to successfully print it. Thank you for sharing it! Now I need to post-process it and am wondering if you can explain how you post-processed your print? I have never done the post-processing before and am not sure the best approach to take. I have attached a picture of our printed brain for your reference. Thank you in advance for insight you can offer!" RESPONSE: Based on the picture you attached, it looks like you used a single extruder printer and printed both the supports and model in the same material, presumably PLA. You need to tear off the supports using pliers. This can be a time-consuming job as getting in every nook and cranny can be difficult. If you find the supports are stuck to much to the model, you may have to adjust some of the settings in your slicer software to compensate. There may be a rough surface where the supports touch the model that you can sand off. If you have a dual extrusion printer, you can print the supports using a water soluble material such as PVA, which makes the supports easy to remove by soaking in water. Dual extruders can be finicky and you will likely have to spend a lot of time trying out different settings to get the supports to work just right, including calibrating the XY offset of the second extruder, determining optimal print temperature for the PLA and support to work together, overhang speed, support infill percentage, etc. This process is very time consuming but gratifying once you get your printer dialed in. If you don't want to deal with the headache, embodi3D has a 3D printing service and can print and ship to you. Hope this helps. Dr. Mike
  2. Version 1.0.0

    216 downloads

    This is an anonymized CT scan DICOM dataset to be used for teaching on how to create a 3D printable models., tutorial, 3d, printing, model, dataset, ct, dicom, base, skull, head, petrous, ridge, mastoid, cells, clivus, atlas, axis, cervical, spine, neck, muscles, infrahyoid, suprahyoid, trachea, lower, turbinate, pharynx, larynx, esophagus, prevertebral, bone, 3d,

    Free

  3. Bones The main advantage of the orthopedical presurgical 3d printed models is the possibility to create an accurate model, which can be used for metal osteosynthesis premodelling - the surgeons can prepare (bend, twist, accommodate) the implants prior the operation. After a sterilisation (autoclaving, UV-light, gamma-ray etc etc), those implants can be used in the planned surgery, which will decrease the overall surgery time (in some cases with more than an hour) with all it's advantages, including a dramatic decreasing of the complication rates, the X-ray exposure for the patient and for the surgeons, the cost and the recovery rates etc etc. For this purpose, you need a smooth bone model, with clearly recognizable and realistic landmarks, realistic measurements and physical properties, close to the real bone. Traditionally, the orthopedical surgeons in my institution used polystyrene models, made by hand, now they have access to 3d printed models and they are better in any way. Here are some tips how to print that thing. 1. Method - FDM. The bone models are the easiest and the most forgiving to print. You can make them with literally every printer you can find. FDM is a strong option here and, in my opinion, the best method on choice.2. Matherial - PLA - it's cheap, it's easy to print, it's the bread and butter for the bone printing. Cool extruding temperature (195-200C) decrease the stringing and increases the details in the models.3. Layer heigh - 0,150mm. This is the best compromise between the print time, the quality and the usability of the models.3. Perimeters (shell thickness) - 4 perimeters. One perimeter means one string of 3d printed material. It's width depends on the nozzle diameter and the layer thickness. For Prusa MK3 with 0,4mm nozzle 1 perimeter is ~0,4mm. To achieve a realistic cortical bone, use 4 perimeters (1,7mm). The surgeons loves to cut stuff, including the models, in some cases I have to print several models for training purposes. 4 perimeters PLA feels like a real bone.4. Infill - 15% 3d infill (gyroid, cuboid or 3d honey comb). The gyroid is the best - it looks and feels like a spongy bone. It's important to provide a realistic tactile sensation for the surgeons, especially the trainees. They have to be able to feel the moment, when they pass the cortical bone and rush into the spongiosa.5. Color - different colors for every fracture fragment. If the model is combined with a 3D visualization, which colors corresponds with the colors of the 3d print, this will make the premodelling work much easier for the surgeons. Also, it looks professional and appealing. 6. Postprocessing - a little sanding and a touch of a acrylic varnish will make the model much better.7. Support material - every slicer software can generate support, based on the angle between the building platform and the Z axis of the model. You can control this in details with support blockers and support enforcers, which for the bones is not necessary, but it's crucial for the vessels and the heart.Conclusions - the bone models are easy to make, they look marvelous and can really change the outcome of every orthopedical surgery.
  4. The Coalition for Imaging and Bioengineering Research (CIBR) is a dedicated partnership of academic radiology departments, patient advocacy groups, and industry with the mission of enhancing patient care through advances in Biomedical Imaging. My good friend and colleague Dr. Beth Ripley and I recently participated in the sixth annual Medical Technology Showcase at Capitol Hill organized by CIBR, representing the Department of Radiology at the Brigham and Women’s Hospital (BWH) where we emphasized the importance of 3D printing in healthcare. The annual Medical Technology showcase aims to bring examples of medical breakthroughs in imaging and bioengineering to members of congress and demonstrate how these advances are impacting patient care. In addition to educating policy makers and the public about innovative imaging technology, the event demonstrates the value of NIH funded academic research and the importance of collaborations between academia, industry and patient advocacy groups. Our display booth comprised of the Department of Radiology at BWH, the Lung Cancer Alliance, and Fujifilm was a hit among attendees and we were pleased to see the level of interest in medical 3D printing. We displayed 3D printed models that have been used for different clinical applications and our booth partners from Fujifilm demonstrated Synapse 3D, a software that allows conversion of 2D image data from CT/MRI into 3D printable files. Our goal was to demonstrate the importance of 3D printing in pre-surgical planning and how it can benefit patients by allowing surgeons to devise a patient specific treatment strategy and minimize post-surgical complications. Sheila Ross, a lung cancer survivor and patient advocate from the Lung Cancer Alliance emphasized how 3D printed models can give patients and their families a better understanding of the planned procedure. A lung model from Fujifilm demonstrating a nodule (green) and surrounding bronchioles The Lung & Brain cookies might have been slightly more popular than our 3D models It is our hope that more funding and resources will be allocated to investigate innovative medical technologies such as 3D printing, which can then be translated to impact patient care. In order to transform 3D printing from being a fad, to a mainstream tool that fosters precision medicine, evidence based benefits of its different applications will need to be demonstrated in clinical trials which will require funding. Tatiana Kelil, MD
  5. 166 downloads

    This anatomically accurate 3D printable sphenoid bone was created by Dr. Marco Vettorello, who has graciously given permission to share it here. The sphenoid bone forms the base of the skull. It houses the sella turcica, which protects the pituitary gland and the sphenoid air cells which are part of the paranasal sinus system. The file is in STL format and compressed with ZIP. This file is also available here.

    Free

  6. Vascular Training Models Venous Models: IVC Filter Deployment/Retrieval Model: VIVC01000M Iliac Vein Stenosis Extension Model: VIVC01E2SC Gonadal Vein Embolization Extension Model: VGON01000C Femoral Vein Extension Model: VFEM01000C Flexible SVC Extension Model: VSVC01000F Vascular Training Models Arterial Models: Extendable Abdominal Aorta Model: AABD02000C Upper and Lower Leg Extension Model: AALE01000C Abdominal Aortic Aneurysm EVAR Model: AAAA01000C Stand-Alone Abdominal Aorta Model: AABD01000C Description: The gonadal vein embolization model is a two-part model that is compatible with the standard IVC filter deployment/ retrieval model. It consists of a modified IVC segment that snaps into place in the IVC position, and a distal gonadal vein segment. The pathologically dilated gonadal vein is from a real patient with severe pelvic congestion syndrome and consists of a dilated left gonadal vein that measures 11 mm in diameter. The abnormal vein can be accessed from the femoral or jugular approach and is perfect for deploying coils, occlusion devices, or foam. Once deployed the embolization devices can be easily removed. Contact us for model information and prices
    Procedures that this model can teach or practice: Gonadal vein embolization Renal vein sampling Adrenal vein sampling Compatibility: Iliac vein stenosis extension model (# VIVC01E2SC) Femoral vein extension model (# VFEM01000C) Flexible SVC extension model (# VSVC01000F) Required models: This model should be used with the IVC Filter Deployment and Retrieval Model (# VIVC01000M) For questions and pricing contact us. Please include the model name and number with your inquiry: Gonadal Vein Embolization Extension Model (# VGON01000C)
  7. Vascular Training Models Venous Models: IVC Filter Deployment/Retrieval Model: VIVC01000M Iliac Vein Stenosis Extension Model: VIVC01E2SC Gonadal Vein Embolization Extension Model: VGON01000C Femoral Vein Extension Model: VFEM01000C Flexible SVC Extension Model: VSVC01000F Vascular Training Models Arterial Models: Extendable Abdominal Aorta Model: AABD02000C Upper and Lower Leg Extension Model: AALE01000C Abdominal Aortic Aneurysm EVAR Model: AAAA01000C Stand-Alone Abdominal Aorta Model: AABD01000C Description: The iliac vein stenosis model is a single piece that replaces Part E (common iliac veins) in the IVC filter model. This model contains a high grade stenosis in the proximal left common iliac vein, the classic position of the so-called May-Thurner stenosis. In May-Thurner syndrome, chronic compression and scarring of the proximal left common iliac vein, is caused by the crossing right common iliac artery. This results in stenosis of the left common iliac vein, slow blood flow, and eventually clotting and formation of deep vein thrombosis (DVT). After the DVT is cleared with anticoagulation or thrombectomy/thrombolysis, the iliac vein stenosis must be treated with venous stenting. Contact us for model information and prices This model has a 4 mm thick, 9 mm wide stenosis at the crossing point between the left common iliac vein and the right common iliac artery. It is perfect for practicing venous stenting and thrombectomy/ thrombolysis.
    Procedures that this model can teach or practice: venous stenting venous thrombectomy venous thrombolysis venous catheterization Compatibility: Gonadal vein embolization extension model (# VGON01000C) Femoral vein extension model (# VFEM01000C) Flexible SVC extension model (# VSVC01000F) Required models: This model should be used with the IVC filter deployment/ retrieval model (# VIVC01000M) For questions and pricing contact us. Please include the model name and number with your inquiry: Iliac Vein Stenosis Extension model (# VIVC01E2SC)
  8. Vascular Training Models Venous Models: IVC Filter Deployment/Retrieval Model: VIVC01000M Iliac Vein Stenosis Extension Model: VIVC01E2SC Gonadal Vein Embolization Extension Model: VGON01000C Femoral Vein Extension Model: VFEM01000C Flexible SVC Extension Model: VSVC01000F Vascular Training Models Arterial Models: Extendable Abdominal Aorta Model: AABD02000C Upper and Lower Leg Extension Model: AALE01000C Abdominal Aortic Aneurysm EVAR Model: AAAA01000C Stand-Alone Abdominal Aorta Model: AABD01000C Description: The IVC filter deployment/retrieval medical training model includes all the major venous structures in the human torso from the right jugular vein of the neck to the right and left common femoral veins at the level of the hips. The model allows for the education and training in a variety of venous and IVC filter related procedures. The model was created from a real CT scan so the vessel positions, diameters, and angles are all real. Entry points are present at the right jugular vein and brachiocephalic vein for upper body access, and the bilateral common femoral veins for lower body access. Attachments are present to make placement of a real vascular sheath easy. The model can be used to illustrate specific devices for the procedures listed and is used by medical device companies to demonstrate and teach the use of their products. The IVC model comes in a rugged and portable carrying case and is easily transportable. It assembles and disassembles in less than 20 seconds. A variety of extensions are available to expand the number of procedures that can be simulated. Contact us for model information and prices
    Procedures that this model can teach or practice: IVC filter placement, jugular or femoral approach Common iliac filter placement, jugular or femoral approach IVC filter retrieval Venous stenting IVC and iliac vein thrombectomy or thrombolysis Venous embolization Hepatic vein cannulation Compatibility: Iliac vein stenosis extension model (# VIVC01E2SC) Gonadal vein embolization extension model (# VGON01000C) Femoral vein extension model (# VFEM01000C) Flexible SVC extension model (# VSVC01000F) For questions and pricing contact us. Please include the model name and number with your inquiry: IVC Filter Deployment and Retrieval model (# VIVC01000M)
  9. I'm trying to 3d print my own skull just for fun and well I have the DCOM file but every time when I try and convert it the whole skull doesn't come out. Whenever I convert the DCOM file any of them it only gives me from the top do about the middle of the eye socket and i want the whole thing. Can someone please help me and tell me what i might be doing wrong.
  10. I receive a lot of inquiries to my account. I'm going to try to share them with the community in the hope that any information that is shared can help many others. A member recently contacted me and asked the following: "I am a Biomaterials and Tissue Engineer by profession and recently got into 3d printing of medical implants. I would be greatly obliged if you could please advice me on designing 'cranial mesh' My task is to design titanium based cranial mesh. I would like to know if you can suggest me any tutorial on the same." Another member asks, " I am a resident in neurosurgery in Brazil and I have a dream to allow cheap cranioplasty for those in need that depend on Brazilian public health system. If you have some sort of tutorial using free software to make those prosthetic cranial grafts of a cheap way to make a mold out of it I will be glad to hear from you. I am planning on buying the ultimaker 2 printer which allows direct PEEK print and also PLA print for mold to go through autoclave." I must admit that I have limited experience with craniofacial implants. I know that the physicians at Walter Reed Army Medical Center in Bethesda Maryland are doing pioneering work in the field. Regarding making titanium-based implants I am unaware of any tutorials, but a search on Pubmed has yielded a few helpful articles. Here is one https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4073471/ From what I have seen most of these implants are designed using the Mimics system by Materialise. Regarding the low-cost solution for cranial implants, I'm not familiar with any freeware software that specifically does implants. From the hardware perspective, you may want to consider a Form 2 stereolithographic printer in addition to the Ultimaker 2 (FYI, there is a new Ultimaker 3 printer out). Formlabs, the makers of the Form 2 have a tutorial on using their printer to make molds for casting. https://formlabs.com/blog/3d-printing-for-injection-molding/ Formlabs has a dental biocompatible resin that I know some hospitals (Mayo Clinic) are using for in-surgery cutting guides. I heard them talk about that at a conference I recently attended. Whatever you do, make sure you follow the health safety rules in your country and take all necessary steps for patient safety.
  11. 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!
  12. 1,008 downloads

    -> IMPROVED VERSION OF THIS FILE IS AVAILABLE HERE <-- This 3D printable model of a human heart was generated from a contrast enhanced CT scan. The model comes in 4 slices, and demonstrates the detailed anatomy of the human heart in exquisite detail. Each slice stacks on top of the prior slice to form a complete human heart. Individual slices show the detailed cardiac anatomy of the right and left ventricles, and right and left atria, and outflow tracts. Perfect for educational purposes. Download this model for free and 3D print the model yourself! If you find this and other free medical models available for download on Embodi3d.com useful, please give back to the community by uploading and sharing a medical model of your design.

    $19.99

  13. 607 downloads

    This anatomically accurate human heart was created by Dr. Marco Vettorello, who has graciously given permission to share it here. The file is in STL format and compressed with ZIP. This file is also available here.

    Free

  14. From the album: embodi3D 3D Printed Models

    This is sheep heart model 3D printed in elastic for flow testing of implantable aortic valves. Note the custom manifold attachments. To learn more about our services, click this link. https://www.embodi3d.com/custom-3d-printing-for-medical-device-development/
  15. Hello the Biomedical 3D Printing community, it's Devarsh Vyas here writing after a really long time! This time i'd like to share my personal experience and challenges faced with respect to medical 3D Printing from the MRI data. This can be a knowledge sharing and a debatable topic and I am looking forward to hear and know what other experts here think of this as well with utmost respect. In the Just recently concluded RSNA conference at Chicago had a wave of technology advancements like AI and 3D Printing in radiology. Apart from that the shift of radiologists using more and more MR studies for investigations and the advancements with the MRI technology have forced radiologists and radiology centers (Private or Hospitals) to rely heavily on MRI studies. We are seeing medical 3D Printing becoming mainstream and gaining traction and excitement in the entire medical fraternity, for designers who use the dicom to 3D softwares, whether opensource or FDA approved software know that designing from CT is fairly automated because of the segmentation based on the CT hounsifield units however seldom we see the community discuss designing from MRI, Automation of segmentation from MRI data, Protocols for MRI scan for 3D Printing, Segmentation of soft tissues or organs from MRI data or working on an MRI scan for accurate 3D modeling. Currently designing from MRI is feasible, but implementation is challenging and time consuming. We should also note reading a MRI scan is a lot different than reading a CT scan, MRI requires high level of anatomical knowledge and expertise to be able to read, differentiate and understand the ROI to be 3D Printed. MRI shows a lot more detailed data which maybe unwanted in the model that we design. Although few MRI studies like the contrast MRI of the brain, Heart and MRI angiograms can be automatically segmented but scans like MRI of the spine or MRI of the liver, Kidney or MRI of knee for example would involve a lot of efforts, expertise and manual work to be done in order to reconstruct and 3D Print it just like how the surgeon would want it. Another challenge MRI 3D printing faces is the scan protocols, In CT the demand of high quality thin slices are met quite easily but in MRI if we go for protocols for T1 & T2 weighted isotropic data with equal matrix size and less than 1mm cuts, it would increase the scan time drastically which the patient has to bear in the gantry and the efficiency of the radiology department or center is affected. There is a lot of excitement to create 3D printed anatomical models from the ultrasound data as well and a lot of research is already being carried out in that direction, What i strongly believe is the community also need advancements in terms of MRI segmentation for 3D printing. MRI, in particular, holds great potential for 3D printing, given its excellent tissue characterization and lack of ionizing radiation but model accuracy, manual efforts in segmentation, scan protocols and expertise in reading and understanding the data for engineers have come up as a challenge the biomedical 3D printing community needs to address. These are all my personal views and experiences I've had with 3D Printing from MRI data. I'm open to and welcome any tips, discussions and knowledge sharing from all the other members, experts or enthusiasts who read this. Thank you very much!
  16. E-Nabling the Future is a volunteer organization dedicated to creating inexpensive 3D printable prosthetic hands and arms for children around the globe who are missing limbs. The movement has grown from an informal collaboration to a veritable movement, and they are now producing functional and inexpensive prosthetic limbs. Traditionally designed arm and hand prostheses can cost up to $40,000. According to 3Dprint.com, it is now possible to create an entire functional my electric arm for $350. Their most recent innovation uses electrical impulses from the bicep muscle to open and close the hand. This enabled a six-year-old boy named Alex who is missing his right arm to give his mother a big hug. The picture of Alex's myoelectric prosthetic right hand gave me a sense of déjà vu -- I swear I had seen something like this before. Then it hit me. The prosthetic is eerily similar to Luke's prosthetic hand in The Empire Strikes Back. Thanks to the volunteers at E-Nabling the Future, science fiction is becoming science fact, and children are the beneficiaries of this amazing movement. Please check out the E-Nabling the Future website, and if you are so inclined give a donation to this worthy cause. For updates on news and new blog entries, follow us on Twitter at @Embodi3D. Select images by Kt Crabb Photography
  17. I've been working on ways to artistically expand on 3D printed anatomic models beyond an exact replica of the anatomy. My first project is this Lace Skull. The skull is based on an anatomically accurate skull generated from a CT scan. I have made several of the earlier skull models available for download on the Embodi3D website here and here. Using a variety of methods, I have transformed the skull and given it a unique lace-like appearance. The overall surface contours are still anatomically accurate. The lace-like texture gives the model its unique aesthetic but also cuts down on printing material while maintaining mechanical strength. I have made the STL files available for FREE download in the File Vault section of the Embodi3D website. You can find the STL files here (HALF-SIZE | FULL-SIZE). If you 3D print this file, please report back regarding your outcome. I printed a half-size model using the "White, Strong & Flexible" nylon material on Shapeways. If you would rather have Shapeways print the model and ship it to you for a fee, you can go Shapeways to directly order the models here (HALF-SIZE | FULL-SIZE). I hope you enjoy this 3D printable model. Please report back on your experiences with printing the model. Also, please share your own 3D printable creations with the community in the File Vault section of the website.
  18. UPDATED TUTORIAL: A Ridiculously Easily Way to Convert CT Scans to 3D Printable Bone STL Models for Free in Minutes Hello, it's Dr. Mike here again with another tutorial and video on medical 3D printing. In this tutorial we're going to learn how to take a DICOM-based medical imaging scan, such as a CT scan, and convert into an STL file in preparation for 3D printing. We will use the free, open-source software program Osirix to do this. Once the file is converted into STL format, we will use the free software packages Blender and Meshmixer to prepare the file for 3D bioprinting. If mastered, this material should easily allow you to make a high-quality 3D printed medical model in less than 30 minutes using free software. Expensive, proprietary software is not needed. This tutorial is designed primarily for Macintosh users since Osirix is a Macintosh-only program. If you use Windows or Linux, please stay tuned for my upcoming tutorial on using free, open-source 3D Slicer to create medical and anatomic models. If you haven't already done so, please see my tutorial on selecting the best medical scan to create a 3D printed model. If you start your 3D printed model project with the wrong kind of scan, your model will not turn out well. Selecting the right kind of scan is critically important and will save you a lot of frustration. Take a few minutes to look over this brief tutorial. It will be well worth your time. Before you start, DOWNLOAD THE FILE PACK that accompanies this video so you can follow along on your own computer. When you finish the tutorial, you will have your very own 3D printable skull STL file. Download is free for members, and registration for membership is also free and only takes a minute. Video 1: The video version of this tutorial. It takes you from start to finish in 30 minutes. The written version here has more detail though. A Few Brief Definitions What is Osirix? Osirix is a Macintosh-only software package for reading medical imaging scans (Figure 1). There are several versions. There is an FDA-approved version designed for doctors reading scans in clinics and hospitals, a 64-bit version for research and other nonclinical activities, and a free, 32-bit version. The main difference between the free 32-bit version and the paid 64-bit version is the 64-bit version can open very large imaging studies, such as MRI exams with thousands of images. The 32-bit version is limited to about 500 images. Additionally, there is a performance boost with the paid versions. If you are just getting into 3D bioprinting, the free, 32-bit version is a great place to start. It can be downloaded at the Osirix website here. Figure 1: An example of Osirix being used to read a CT scan. What is DICOM? DICOM stands for Digital Imaging and Communications in Medicine. It is the standard file format for most medical imaging scans, such as Computed Tomography (CT), Magnetic Residence Imaging (MRI), ultrasound, and x-ray imaging studies. What is STL? STL, or STereoLithography format , is an engineering file format created by 3D Systems for use with Computer Aided Design software (CAD). The file format is primarily used in engineering, and has become the standard file format for 3D printing. The Problem with 3D Printing Anatomic Structures The major problem with trying to 3D print anatomic structures from medical scans is that the medical scan data is in DICOM format and 3D printers require files in STL format. The two formats are incompatible. There are very expensive, proprietary software packages that can perform the conversion between DICOM and STL. A little-known secret is that this can also be done using free, open-source software. Osirix is the best solution for Macintosh. 3D Slicer is the best solution for Windows and Linux. I will discuss 3D Slicer in an upcoming tutorial. If you haven't already, please download the DICOM data set we will be using in this tutorial. This data set is from a high quality CT scan of the brain and skull. It has been anonymized and has been put in the public domain for research by the US National Cancer Institute. Also included with the download packet are other files we will use for this tutorial, including the final STL file of the skull. The download is free for members, and registration for membership is also free and only takes a minute. From the Macintosh Finder navigate to the folder with the downloaded tutorial file pack and double-click on the file TCGA-06-5410 sharp.zip. Opening the CT scan with Osirix Open Osirix. From the File menu, click Import, Import Files. Click Open. (Figure 2) Figure 2: Importing the CT scan into Osirix Navigate to the folder that contains your DICOM data set. Click the Open button. Osirix will ask you if you want to copy the DICOM files into the Osirix database, or only copy the links to these files. Click "Copy Files." Osirix will begin to copy the files into the database. A progress bar will be shown on the lower left-hand corner. When the data is imported you'll see a small orange circle with a "+" in it. This orange circle will eventually go away when Osirix is finished analyzing the study, but you can open the study and work with it while Osirix does some cleanup postprocessing. Left click on the study. You will see an icon with a label "FIDUCIALS 1.0 SPO cor, 216 Images." This is a CT scan of the head with coronal slices at 1 mm intervals. Double-click on this icon, Figure 3. Figure 3: The study when opened Osirix will remind you that you're not supposed to be using it for diagnostic scan reading on real patients unless you are using the more expensive FDA approved version, Osirix MD we're just using it to create a 3D model, so click "I agree." At this point, the study will load. Use the mouse wheel or the bar on the top of the screen to scroll. You can see that this is a pretty decent CT scan of the head for 3D printing. There is not much artifact from metallic dental implants because the maxilla and mandible have been cut off. Segmenting the bony skull and creating a new series We can measure the density of the bony structures using the Region Of Interest or ROI tool. This measures the Hounsfield density, or CT density, of the target area. Select the oval tool from the drop-down menu, Figure 4. Figure 4: The ROI tool. Choose a region of bone using the oval tool. You will see that information about this region is displayed. What we are interested in is the mean density, which in this case is 1753.194, Figure 5. Figure 5: Density measurement using ROI tool. The mean density is 1753.194, as shown in maroon field. Use the ROI tool to select another region in the brain. You will see that the mean attenuation, or density, is much less, in this case 1059.137, Figure 6. Figure 6: Density measurement of the brain tissue. Finally, use the oval tool to choose an area in the air adjacent to the head. You can see that the mean attenuation of this region is 38.514, Figure 7. Figure 7: Density measurement of air. In this scan the Hounsfield attenuation numbers have been shifted. In a typical scan, air measures about -1000, soft tissue between 30 and 70, and bone typically greater than 300. In this scan those numbers have been increased by 1000. Since we were thorough enough to check the Hounsfield attenuation before moving on, we can easily correct for this shift. Under ROI menu select Grow Region 2D/3D Segmentation, Figure 8. Figure 8: The Grow Region tool In the Segmentation Parameters window that pops up, set the following: Lower Threshold 1150 Upper Threshold 3000. Generate a new series with: Inside pixels 1000 Outside pixels 0 Be sure to check the checkbox next to the Set Inside Pixels, and Set Outside Pixels fields, Figure 9. Figure 9: Setting up the Segmentation Parameters window. Next, make sure you select a starting point for the algorithm. Left click on one of the skull bones. Green crosshairs will show. All of the bone that is contiguous with point you clicked will now be highlighted in green, Figure 10. Figure 10: Setting the starting point for segmentation. The target region turns green. Click the Compute button Osirix will generate a new series with the bones being a single white color with a value of 1000, and everything else being a black color with a value of zero, Figure 11. Creating a separate series just for 3D printing purposes is the secret to getting good 3D models from Osirix. Trying to generate a 3D surface model directly from the 3D Surface Rendering function underneath the 3D Viewer menu is tempting to use, however it will not work well for generating STL files. This is not obvious, and the source of much frustration for beginners trying to use Osirix for 3D printing. Figure 11: The new bitmapped series shown on right of screen. This series has only two colors, black and white. It is idea for conversion to and STL surface model. Generating an STL file from the new bitmapped series Now we are ready to create our 3D surface model. Make sure that your new bitmapped series is highlighted. Click on the 3D viewer menu and select 3D Surface Rendering, Figure 12. Leave the settings set to their default values. Click OK as shown in Figure 13. Figure 12: Selecting 3D Surface Rendering Figure 13: Setting 3D surface rendering settings Osirix will then think for a few moments as it prepares the surface. You can see that a relatively good approximation of the skull has been generated. Use of the left mouse button to rotate the 3D model. Next were going to export the 3D surface model to an STL file. Click Export 3D-SR and choose Export as STL as show in Figure 14. Type the file name "skull file." Click Save. Figure 14: Exporting model to STL file format. Cleaning up the 3D model in Blender You can see from the 3D rendering that there are many small islands of material that have been included with the STL file. Also, the skull has a very pixelated appearance. It does not have the smooth surface that would be expected on a real skull. In order to fix these problems, we're going to do a little postprocessing in Blender, a free open-source 3D software program. If you don't already have Blender on your computer, you can download it free from blender.org. Blender is available for Windows, Macintosh, and Linux. Select your operating system, preferred installation method, and download mirror. Once Blender is installed on your computer, open it. In the default scene there will be a cube. We don't need this. Right click on the cube to select it. Then delete it using the delete key on a full keyboard or the X key on a laptop keyboard. Blender will ask you to confirm you want to delete the object. Click Delete as shown in Figure 15. Figure 15: Deleting the default cube. Next, we are going to import the skull STL file. From the File menu select Import, STL, as shown in Figure 16. Navigate to the skull STL file you saved from Osirix, and double-click it. Blender will think for a few seconds and then return to what appears to be an empty scene, as shown in Figure 17. Where is your skull? To find your skull, use the mouse scroll wheel to zoom out. If you zoom out far enough you will see the skull. The skull appears to be gigantic, as shown in Figure 18. This is because the default unit of measurement in the skull is 1 mm. In Blender, an arbitrary unit of measurement called a "blender unit" is used. When the skull was imported, 1 mm of real size was translated into 1 blender unit. Thus the skull appears to be hundreds of blender units large, and appears very big. Figure 16: Importing the STL file into Blender Figure 17: The "empty" scene. Where is the skull? Figure 18: Zoom out and the skull appears! The skull is also offset from the origin. We are going to correct that. Make sure that the skull is still selected by right clicking on it. If it is selected it will have a orange halo. In the lower left corner of the window click on the Object menu. Select Transform, Geometry to Origin as shown in Figure 19. The skull is now centered on the middle of the scene. Figure 19: Centering the skull in the scene. Deleting Unwanted Mesh Islands First, let's get rid of the extra mesh islands. There is a menu in the lower left-hand corner of the window that says Object Mode. Click on this and go to Edit Mode, as shown in Figure 20. Figure 20: Entering Edit mode in Blender. Now we are in Edit Mode. In this mode we can edit individual edges and vertices of the model. Right now the entire model is selected because everything is orange. In edit mode you can select vertices, edges, or faces. This is controlled by the small panel of buttons on the bottom toolbar. Make sure that the leftmost or vertex selection mode is highlighted and then right click on a single vertex on the model, as shown in Figure 21. That vertex should become orange and everything else should become gray, because only that single vertex is now selected, Figure 22. Figure 21: Vertex selection mode Figure 22: Select a single vertex by right clicking on it. Under the Select menu, click Linked, as shown in Figure 23. Alternatively, you can hit Control-L. This selects every vertex that is connected to the initial vertex you selected. All the parts of the model that are contiguous with that first selection are now highlighted in orange. You can see that the many mesh islands we wish to get rid of are not selected. Figure 23: Selecting all linked vertices. We are next going to invert the selection. Do this by again clicking on the Select menu and choosing Inverse, Figure 24. Alternatively, you can hit Control-I. Now, instead of the skull being selected, all of the unwanted mesh islands are selected, as shown in Figure 25. Now we can delete them. Hit the delete key, or alternatively the X key. Blender asks you what you want to delete. Click Vertices, Figure 26. Now all of those unwanted mesh islands have been deleted. Figure 24: Inverting the selection. Figure 25: The result after inverting the selection. Only the unwanted mesh islands are selected! Figure 26: Deleting the unwanted mesh islands. Repairing Open Mesh Holes We can see that on the top of the skull there is a large hole where the skull was cut off by the scanner. Because the bone surface was cut off, Osirix left a gaping defect, Figure 27. Before 3D printing, this will have to be corrected. This is what is called a manifold mesh defect. It is an area where the surface of the model is not intact. A 3D printer will not know what to do with this, such as whether it should be filled in or left hollow. Fortunately, it is relatively easy to correct. Figure 27: A large open mesh hole at the top of the skull. Using the Select menu in the lower left-hand corner, click on Non-Manifold. This will select all of the non-manifold mesh defects in your model. You can see that the edge of our large hole at the top of the skull has been selected and turned orange. This confirms that this defect has to be fixed. Unselect by hitting the A key. Then, go to Edge select mode by clicking on the Edge Select button along the lower toolbar. Holding down the Alt key, right-click on one of the edges of the target defect, in this case the top of the skull. That familiar orange ring has formed. Your selection should look like Figure 28. Let's fill in this hole by creating a new face. Hit the F key. This creates a new face to close this hole, Figure 29. Figure 28: The edge of the hole is selected, as indicated by the orange color. Figure 29: The hole when filled with a new face. Due to the innumerable polygons along the edges, the face is actually quite a complex polygon itself. Let's convert it to a simpler geometry. With the face still selected hit Control T. You can alternatively go to the Mesh menu and select Faces, Triangulate Faces as shown in Figure 30. This will convert the complicated face into simpler triangles. As you can see, some of these triangles are quite large relative to the other triangles along the skull surface. These large triangles may become apparent when smoothing algorithms are applied or 3D printing is performed. Let's reduce their size. Hit the W key and then select Subdivide Smooth, as shown in Figure 31. The triangles are now subdivided. Let's repeat that operation again so that they are even smaller. Hit the W key and again select Subdivide Smooth. Figure 30: Converting all faces into triangles. ] Figure 31: Subdividing and smoothing the selected faces. Smoothing the Model Surface Next let's get rid of that pixelated appearance of the model surface. First, we need to convert all of the polygons in the model to triangles. The smoothing algorithms just work better with triangles. Staying in Edit mode, hit the A key. The A key toggles between selecting all and unselecting all. If you need to, hit the A key a second time until the entire model is orange, thus indicating that it is selected. Hit Control-T, or alternatively use the Mesh menu, Faces, Trangulate Faces. This will convert any remaining complex polygons to triangles. Go back to Object mode by hitting the tab button or selecting Object Mode from the bottom toolbar. We are now going to apply a smoothing function, called a modifier, to the skull. Along the right of the screen you'll see a series of icons, one of which is a wrench, as shown in Figure 32. Click on that. This brings up the modifier panel, a series of tools that Blender uses to manipulate digital objects. Click on the Add Modifier button and select the Smooth modifier. Do not select the Laplacian Smooth modifier. That is different. We just want the regular Smooth modifier, as shown in Figure 33. Leaving the Factor value at 0.5, increase the Repeat factor until you are satisfied with the surface appearance of your model. For me, a factor of 20 seemed to work, Figure 34. At this point the modifier is only temporary, and has not been applied to the model. Click on the Apply button. Now the smoothing function has been applied to the model. Figure 32: The Modifiers toolbar on the right. Figure 33: The Smooth modifier Figure 34: Setting the Smooth modifier to repeat 20 times. Rotating and Adjusting the Model Orientation When the model was originally exported from Osirix and opened in Blender, it was at a strange orientation. We can correct to this easily. Click on the View menu from the left portion of the lower now bar and select Front. This orients the model from the frontal view, and you can see that in this orientation we are looking at the top of the skull. To correct this, we will rotate the model along the X axis. First, make sure that the cursor is inside the model window. Then, Hit the R key and then the X key, and type "180." This will rotate the model on the X axis by 180°. Hit the return key to confirm the modification. Don't worry if the skull isn't facing the correct way right now, we will fix that later. Now we are ready to export our cleaned up skull model. Go to the File menu, click Export, STL. Navigate to your desired folder and save your STL file. Since I corrected several defects in this mesh file, I called the file "skull file corrected.stl" Performing a Final Inspection Using Meshmixer If you haven't already done so, go to the Autodesk Meshmixer website at http://www.meshmixer.com/download.html and download and install Meshmixer. The software is free. Once installed open the program and select Import. Navigate to your STL file and double-click it. Meshmixer has a variety of nice features, and one of them is a mesh correction function. Once your file is open click on the Analysis button along the left nav bar. Click on Inspector as shown in Figure 35. Meshmixer will now analyze the STL file for obvious mesh defects. Anything that is detected will be highlighted by red, pink, or blue lines. You can see that our skull model appears to be defect free. Click on the done button and quit Meshmixer. Figure 35: Running the inspector tool in MeshMixer Your STL file of the skull is now ready for 3D printing! Conclusion In this tutorial you have learned how to take a DICOM data set from a CT scan and use it to create a 3D printable STL file using free software. First we used the Osirix to segment a CT scan and convert it to an STL file. Then we performed cleanup operations on the STL file using the Blender and Meshmixer, both free programs. For additional information on how to select an appropriate CT or MRI scan for 3D printing please see my previous tutorial. If you want to learn more about using Blender to fix more extensive defects in bone models, you can view to other tutorials I have created: 3D Printing of Bones from CT Scans: A Tutorial on Quickly Correcting Extensive Mesh Errors using Blender and MeshMixer Preparing CT Scans for 3D Printing. Cleaning and Repairing STL Files from Bones using Blender, an advanced tutorial A variety of useful tutorials for 3D printing is available on the Tutorials page. If you are planning on attending the 2015 Radiological Society of North America (RSNA) meeting in Chicago this November, look for my hands-on course "3D Printing and 3D Modeling with Free and Open-Source Software." I will give more tips and tricks for creating great 3D printed medical models using freeware. I hope you find this tutorial helpful in creating your own medical and anatomic models for 3D printing. Please stay tuned for my next tutorial on using the free, open-source program 3D Slicer to create medical 3D models on Windows and Linux platforms. If you are creating your own 3D printed medical models, please share your models with the Embodi3D community in the File Vault. If you have questions or comments, please leave a comment below or start a discussion thread in the Forums. Sample free downloads A Collection of Free Downloadable STL Skulls for you to 3D print yourself. 3D printable human heart in stackable slices, shows amazing internal anatomy. A Collection of Spine STL files to download and 3D print. Follow Embodi3D on social media Twitter | Facebook | LinkedIn | YouTube | Google+
  19. UPDATED TUTORIAL: A Ridiculously Easily Way to Convert CT Scans to 3D Printable Bone STL Models for Free in Minutes Hello and welcome back. I hope you enjoyed my last tutorial on creating 3D printable medical models using free software on Macintosh computers. In this brief video tutorial I'll show you how to create a 3D printable skull STL file from a CT scan in FIVE minutes using only free and open source software. In the video I use a program called 3D Slicer, which is available from slicer.org. 3D Slicer works on Windows, Macintosh, and Linux operating systems. Also, I use Blender, which is available from blender.org, to perform some mesh cleanup. Finally, I check my model prior to 3D printing using Meshmixer from Autodesk. This is available at meshmixer.com. All software programs are free. If you like this, view my complete tutorial where I go through each step shown here in detail. I hope you enjoy the video.
  20. 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.
  21. Please note that any references to “Imag3D” in this tutorial should be replaced with “democratiz3D” In this tutorial we will discuss how to share, sell, organize, and reprocess 3D printable medical models you make using the free online democratiz3D service from embodi3D. democratiz3D is a powerful tool that automatically converts a medical CT scan into a 3D printable file in minutes with minimal user input. It is no longer necessary to master complicated desktop software and spend hours manually segmenting to create a 3D printable model. Learn how to make high quality medical 3D models with democratiz3D by following my introductory guide to creating medical 3D printing files and my more advanced 3D printing file processing tutorial. Once you create your medical masterpiece, you can share, sell, organize, or tweak your model to make it perfect. This tutorial will show you how. Resubmit your CT Scan for Reprocessing into Bone STL If you are trying to learn the basics of how to convert CT scans into 3D printable STL models, please see my earlier tutorials on basic creation of 3D printable models and more advanced multiprocessing. If you are not 100% satisfied with the quality of your STL model, you can resubmit the input scan file for repeat processing. To do this, go to the page for your input NRRD file. IMPORTANT: this is the NRRD file you originally uploaded to the website, NOT the STL file that was generated for you by the online service. Since both the original NRRD file and the processed STL file have similar titles, you can tell the difference by noting that the NRRD file you uploaded won't have any thumbnails, Figure 1. In most cases, the processed file will have the word "processed" appended to the file name. Figure 1: Choose the original NRRD file, not the generated STL file. You can find your files underneath your profile, as shown in Figure 2. That will show you your most recent activity, including recently uploaded files. Figure 2: Finding your files under your profile. If you uploaded the file long ago or contribute a lot of content to the site, your uploaded NRRD file may not be among the first content item shown. You can search specifically for your files by clicking on See My Activity under your Profile, and selecting Files from the left hand now bar, as shown in Figures 3 and 4. Figure 3: Showing all your activity. Figure 4: Showing the files you own. Once you have found your original NRRD file, open the file page and select File Actions on the lower left-hand corner, as shown in Figure 5. Choose Edit Details as shown in Figure 6. Figure 5: File Actions – start making changes to your file Figure 6: Edit Details Scroll down until you reach the democratiz3D Processing section. Make sure that the democratiz3D Processing slider is turned ON. Then, make whatever adjustments you want to the processing parameters Threshold and Quality, as shown in Figure 7. Threshold is the value in Hounsfield units to use when performing the initial segmentation. Quality is a measure of the number of polygons in the output mesh. Low quality is quick to process and generates a small output file. Low quality is suitable for small and geometrically simple structures, such as a patella or single bone. High quality takes longer to process and produces a very large output file, sometimes with millions of polygons. This is useful for very large structures or complex anatomy, such as a model of an entire spine where you wish to capture every crack and crevice of the spine. Medium quality is a good balance and suitable in most cases. Figure 7: Changing the processing parameters. When you're happy with your parameter choices, click Save. The file will now be submitted for reprocessing. In 5 to 15 minutes you should receive an email saying that your file is ready. From this NRRD file, an entirely new STL file will be created using your updated parameters and saved under your account. Sharing your 3D Printing File on embodi3D.com Sharing your file with the embodi3D community is easy. You can quickly share the file by toggling the privacy setting on the file page underneath the File Information box on the lower right, as shown in Figure 8. If this setting says "Shared," then your file is visible and available for download by registered members of the community. If you wish to have more detailed control over how your file is shared, you can edit your file details by clicking on the File Actions button on the lower left-hand side of the file page, also shown in Figure 8. Click on the Edit Details menu item. This will bring you to the file editing page which will allow you to change the Privacy setting (shared versus private), License Type (several Creative Commons and a generic paid file license are available), and file Type (free versus paid). These are shown in detail in Figure 9. Click Save to save your settings. Figure 8: Quick sharing your file, and the File Actions button Figure 9: Setting the file type, privacy, and license type for your file. Sell your Biomedical 3D Printing File and Generate Income If you would like to sell your file and charge a fee for each download, you may do so by making your file a Paid File. If you have a specialized model that there is some demand for, you can generate income by selling your file in the marketplace. From the Edit Details page under File Actions, as shown in Figure 8, scroll down until you see Type. Choose Paid for the Type. Choose the price you wish to sell your file for in the Price field. This is in US dollars. Buyers will use PayPal to purchase the file where they can pay with Paypal funds or credit card. Make sure that the privacy setting is set to Shared. If you list your file for sale but keep it private and invisible to members, you won't sell anything. Finally, make sure you choose an appropriate license for users who will download your file. The General Paid File License is appropriate and most instances, but you have the option to include a customized license if you wish. This is shown in Figure 10. Figure 10: Configuring settings to sell your file The General Paid File License contains provisions appropriate for most sellers. It tells the purchaser of your file that they can download your file and create a single 3D print, but they can't resell your file or make more than one print without paying you additional license fees. All purchasers must agree to the license prior to download. If you wish to have your own customized license terms, you can select customized license and specify your terms in the description of the file. Organize your file by moving it to a new category If you share your file, you should move the file into an appropriate file category to allow people to find it easily. This is quite simple to do. From the file page, select File Actions and choose the Move item, as shown in Figure 11. You will be able to choose any of the file categories. Choose the one that best fits your particular file. Figure 11: Moving your file to a new category. That's it! Now you can share your amazing 3D printable medical models with the world.
  22. In this brief tutorial we will go over how to use Meshmixer to create a hollow shell from a medical 3D printable STL file. Hollowing out the shell, as shown in the pictures below, can allow you to 3D print the model using much less material that printing a solid piece. The print will take less time and cost less money. For this tutorial we will use a head that we created from a real medical CT scan in a prior tutorial, " Easily Create 3D Printable Muscle and Skin STL Files from Medical CT Scans" If you haven't seen the prior tutorial, please check it out. To follow along with the tutorial, please download the accompanying file. This will enable you to replicate the process exactly as it is shown in the tutorial. >> DOWNLOAD THE TUTORIAL FILE NOW <<
  23. 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!
  24. If you are planning on using the democratiz3D service to automatically convert a medical scan to a 3D printable STL model, or you just happen to be working with medical scans for another reason, it is important to know if you are working with a CT (Computed Tomography or CAT) or MRI (Magnetic Resonance Imaging) scan. In this tutorial I'll show you how to quickly and easily tell the difference between a CT and MRI. I am a board-certified radiologist, and spent years mastering the subtleties of radiology physics for my board examinations and clinical practice. My goal here is not to bore you with unnecessary detail, although I am capable of that, but rather to give you a quick, easy, and practical way to understand the difference between CT and MRI if you are a non-medical person. Interested in Medical 3D Printing? Here are some resources: Free downloads of hundreds of 3D printable medical models. Automatically generate your own 3D printable medical models from CT scans. Have a question? Post a question or comment in the medical imaging forum. A Brief Overview of How CT and MRI Works For both CT (left) and MRI (right) scans you will lie on a moving table and be put into a circular machine that looks like a big doughnut. The table will move your body into the doughnut hole. The scan will then be performed. You may or may not get IV contrast through an IV. The machines look very similar but the scan pictures are totally different! CT and CAT Scans are the Same A CT scan, from Computed Tomography, and a CAT scan from Computed Axial Tomography are the same thing. CT scans are based on x-rays. A CT scanner is basically a rotating x-ray machine that takes sequential x-ray pictures of your body as it spins around. A computer then takes the data from the individual images, combines that with the known angle and position of the image at the time of exposure, and re-creates a three-dimensional representation of the body. Because CT scans are based on x-rays, bones are white and air is black on a CT scan just as it is on an x-ray as shown in Figure 1 below. Modern CT scanners are very fast, and usually the scan is performed in less than five minutes. Figure 1: A standard chest x-ray. Note that bones are white and air is black. Miscle and fat are shades of gray. CT scans are based on x-ray so body structures have the same color as they don on an x-ray. How does MRI Work? MRI uses a totally different mechanism to generate an image. MRI images are made using hydrogen atoms in your body and magnets. Yes, super strong magnets. Hydrogen is present in water, fat, protein, and most of the "soft tissue" structures of the body. The doughnut of an MRI does not house a rotating x-ray machine as it does in a CT scanner. Rather, it houses a superconducting electromagnet, basically a super strong magnet. The hydrogen atoms in your body line up with the magnetic field. Don't worry, this is perfectly safe and you won't feel anything. A radio transmitter, yes just like an FM radio station transmitter, will send some radio waves into your body, which will knock some of the hydrogen atoms out of alignment. As the hydrogen nuclei return back to their baseline position they emit a signal that can be measured and used to generate an image. MRI Pulse Sequences Differ Among Manufacturers The frequency, intensity, and timing of the radio waves used to excite the hydrogen atoms, called a "pulse sequence," can be modified so that only certain hydrogen atoms are excited and emit a signal. For example, when using a Short Tau Inversion Recovery (STIR) pulse sequence hydrogen atoms attached to fat molecules are turned off. When using a Fluid Attenuation Inversion Recovery (FLAIR) pulse sequence, hydrogen atoms attached to water molecules are turned off. Because there are so many variables that can be tweaked there are literally hundreds if not thousands of ways that pulse sequences can be constructed, each generating a slightly different type of image. To further complicate the matter, medical scanner manufacturers develop their own custom flavors of pulse sequences and give them specific brand names. So a balanced gradient echo pulse sequence is called True FISP on a Siemens scanner, FIESTA on a GE scanner, Balanced FFE on Philips, BASG on Hitachi, and True SSFP on Toshiba machines. Here is a list of pulse sequence names from various MRI manufacturers. This Radiographics article gives more detail about MRI physics if you want to get into the nitty-gritty. Figure 2: Examples of MRI images from the same patient. From left to right, T1, T2, FLAIR, and T1 post-contrast images of the brain in a patient with a right frontal lobe brain tumor. Note that tissue types (fat, water, blood vessels) can appear differently depending on the pulse sequence and presence of IV contrast. How to Tell the Difference Between a CT Scan and an MRI Scan? A Step by Step Guide Step 1: Read the Radiologist's Report The easiest way to tell what kind of a scan you had is to read the radiologist's report. All reports began with a formal title that will say what kind of scan you had, what body part was imaged, and whether IV contrast was used, for example "MRI brain with and without IV contrast," or "CT abdomen and pelvis without contrast." Step 2: Remember Your Experience in the MRI or CT (CAT) Scanner Were you on the scanner table for less than 10 minutes? If so you probably had a CT scan as MRIs take much longer. Did you have to wear earmuffs to protect your hearing from loud banging during the scan? If so, that was an MRI as the shifting magnetic fields cause the internal components of the machine to make noise. Did you have to drink lots of nasty flavored liquid a few hours before the scan? If so, this is oral contrast and is almost always for a CT. How to tell the difference between CT and MRI by looking at the pictures If you don't have access to the radiology report and don't remember the experience in the scanner because the scan was A) not done on you, or you were to drunk/high/sedated to remember, then you may have to figure out what kind of scan you had by looking at the pictures. This can be complicated, but don't fear I'll show you how to figure it out in this section. First, you need to get a copy of your scan. You can usually get this from the radiology or imaging department at the hospital or clinic where you had the scan performed. Typically these come on a CD or DVD. The disc may already have a program that will allow you to view the scan. If it doesn't, you'll have to download a program capable of reading DICOM files, such as 3D Slicer. Open your scan according to the instructions of your specific program. You may notice that your scan is composed of several sets of images, called series. Each series contains a stack of images. For CT scans these are usually images in different planes (axial, coronal, and sagittal) or before and after administration of IV contrast. For MRI each series is usually a different pulse sequence, which may also be before or after IV contrast. Step 3: Does the medical imaging software program tell you what kind of scan you have? Most imaging software programs will tell you what kind of scan you have under a field called "modality." The picture below shows a screen capture from 3D Slicer. Looking at the Modality column makes it pretty obvious that this is a CT scan. Figure 3: A screen capture from the 3D Slicer program shows the kind of scan under the modality column. Step 4: Can you see the CAT scan or MRI table the patient is laying on? If you can see the table that the patient is laying on or a brace that their head or other body part is secured in, you probably have a CT scan. MRI tables and braces are designed of materials that don't give off a signal in the MRI machine, so they are invisible. CT scan tables absorb some of the x-ray photons used to make the picture, so they are visible on the scan. Figure 4: A CT scan (left) and MRI (right) that show the patient table visible on the CT but not the MRI. Step 5: Is fat or water white? MRI usually shows fat and water as white. In MRI scans the fat underneath the skin or reservoirs of water in the body can be either white or dark in appearance, depending on the pulse sequence. For CT however, fat and water are almost never white. Look for fat just underneath the skin in almost any part of the body. Structures that contained mostly water include the cerebrospinal fluid around the spinal cord in the spinal canal and around the brain, the vitreous humor inside the eyeballs, bile within the gallbladder and biliary tree of the liver, urine within the bladder and collecting systems of the kidneys, and in some abnormal states such as pleural fluid in the thorax and ascites in the abdomen. It should be noted that water-containing structures can be made to look white on CT scans by intentional mixing of contrast in the structures in highly specialized scans, such as in a CT urogram or CT myelogram. But in general if either fat or fluid in the body looks white, you are dealing with an MRI. Step 6: Is the bone black? CT never shows bones as black. If you can see bony structures on your scan and they are black or dark gray in coloration, you are dealing with an MRI. On CT scans the bone is always white because the calcium blocks (attenuates) the x-ray photons. The calcium does not emit a signal in MRI scans, and thus appears dark. Bone marrow can be made to also appear dark on certain MRI pulse sequences, such as STIR sequences. If your scan shows dark bones and bone marrow, you are dealing with an MRI. A question I am often asked is "If bones are white on CT scans, if I see white bones can I assume it is a CT?" Unfortunately not. The calcium in bones does not emit signal on MRI and thus appears black. However, many bones also contain bone marrow which has a great deal of fat. Certain MRI sequences like T1 and T2 depict fat as bright white, and thus bone marrow-containing bone will look white on the scans. An expert can look carefully at the bone and discriminate between the calcium containing cortical bone and fat containing medullary bone, but this is beyond what a layperson will notice without specialized training. Self Test: Examples of CT and MRI Scans Here are some examples for you to test your newfound knowledge. Example 1 Figure 5A: A mystery scan of the brain Look at the scan above. Can you see the table that the patient is laying on? No, so this is probably an MRI. Let's not be hasty in our judgment and find further evidence to confirm our suspicion. Is the cerebrospinal fluid surrounding the brain and in the ventricles of the brain white? No, on this scan the CSF appears black. Both CT scans and MRIs can have dark appearing CSF, so this doesn't help us. Is the skin and thin layer of subcutaneous fat on the scalp white? Yes it is. That means this is an MRI. Well, if this is an MRI than the bones of the skull, the calvarium, should be dark, right? Yes, and indeed the calvarium is as shown in Figure 5B. You can see the black egg shaped oval around the brain, which is the calcium containing skull. The only portion of the skull that is white is in the frontal area where fat containing bone marrow is present between two thin layers of calcium containing bony cortex. This is an MRI. Figure 5B: The mystery scan is a T1 spoiled gradient echo MRI image of the brain. Incidentally this person has a brain tumor involving the left frontal lobe. Example 2 Figure 6A: Another mystery scan of the brain Look at the scan above. Let's go through our process to determine if this is a CT or MRI. First of all, can you see the table the patient is lying on or brace? Yes you can, there is a U-shaped brace keeping the head in position for the scan. We can conclude that this is a CT scan. Let's investigate further to confirm our conclusion. Is fat or water white? If either is white, then this is an MRI. In this scan we can see both fat underneath the skin of the cheeks which appears dark gray to black. Additionally, the material in the eyeball is a dark gray, immediately behind the relatively white appearing lenses of the eye. Finally, the cerebrospinal fluid surrounding the brainstem appears gray. This is not clearly an MRI, which further confirms our suspicion that it is a CT. If indeed this is a CT, then the bones of the skull should be white, and indeed they are. You can see the bright white shaped skull surrounding the brain. You can even see part of the cheekbones, the zygomatic arch, extending forward just outside the eyes. This is a CT scan. Figure 6B: The mystery scan is a CT brain without IV contrast. Example 3 Figure 7A: A mystery scan of the abdomen In this example we see an image through the upper abdomen depicting multiple intra-abdominal organs. Let's use our methodology to try and figure out what kind of scan this is. First of all, can you see the table that the patient is laying on? Yes you can. That means we are dealing with the CT. Let's go ahead and look for some additional evidence to confirm our suspicion. Do the bones appear white? Yes they do. You can see the white colored thoracic vertebrae in the center of the image, and multiple ribs are present, also white. If this is indeed a CT scan than any water-containing structures should not be white, and indeed they are not. In this image there are three water-containing structures. The spinal canal contains cerebrospinal fluid (CSF). The pickle shaped gallbladder can be seen just underneath the liver. Also, this patient has a large (and benign) left kidney cyst. All of these structures appear a dark gray. Also, the fat underneath the skin is a dark gray color. This is not in MRI. It is a CT. Figure 7B: The mystery scan is a CT of the abdomen with IV contrast Example 4 Figure 8A: A mystery scan of the left thigh Identifying this scan is challenging. Let's first look for the presence of the table. We don't see one but the image may have been trimmed to exclude it, or the image area may just not be big enough to see the table. We can't be sure a table is in present but just outside the image. Is the fat under the skin or any fluid-filled structures white? If so, this would indicate it is an MRI. The large white colored structure in the middle of the picture is a tumor. The fat underneath the skin is not white, it is dark gray in color. Also, the picture is through the mid thigh and there are no normal water containing structures in this area, so we can't use this to help us. Well, if this is a CT scan than the bone should be white. Is it? The answer is no. We can see a dark donut-shaped structure just to the right of the large white tumor. This is the femur bone, the major bone of the thigh and it is black. This cannot be a CT. It must be an MRI. This example is tricky because a fat suppression pulse sequence was used to turn the normally white colored fat a dark gray. Additionally no normal water containing structures are present on this image. The large tumor in the mid thigh is lighting up like a lightbulb and can be confusing and distracting. But, the presence of black colored bone is a dead giveaway. Figure 8B: The mystery scan is a contrast-enhanced T2 fat-suppressed MRI Conclusion: Now You Can Determine is a Scan is CT or MRI This tutorial outlines a simple process that anybody can use to identify whether a scan is a CT or MRI. The democratiz3D service on this website can be used to convert any CT scan into a 3D printable bone model. Soon, a feature will be added that will allow you to convert a brain MRI into a 3D printable model. Additional features will be forthcoming. The service is free and easy to use, but you do need to tell it what kind of scan your uploading. Hopefully this tutorial will help you identify your scan. If you'd like to learn more about the democratiz3D service click here. Thank you very much and I hope you found this tutorial to be helpful. Nothing in this article should be considered medical advice. If you have a medical question, ask your doctor.
  25. In this tutorial we will learn how to easily create a 3D printable dental, orthodontic, or maxillofacial bone model quickly and easily using the free democratiz3D® file conversion service on the embodi3D.com website. Creating the 3D printable dental model takes about 10 minutes and requires no prior experience or specialized knowledge. Dental 3D printing is one of the many uses for democratiz3D. You can 3D print teeth, braces, dental implants and so much more. Step 1: Download the CT scan file for dental 3D printing. Go to the navigation bar on the embodi3D.com website and click on the Download menu. This is shown in Figure 1. Figure 1: The Download menu This will take you to the download section of the website, which has a very large and extensive library of 3D printable anatomy files and source medical scan files. Look for the category along the right side of the page that says Medical Scan Files. Click on the section within that that says Dental, Orthodontic, Maxillofacial, as shown in Figure 2. Figure 2: Viewing the medical scan library on the embodi3D website This section contains anonymized CT scans of the teeth and face. Many of the scans in this section are perfect for 3D printing dental models. For this tutorial we will use the file openbiteupdated by member gcross, although you can use any source CT scan. This particular scan is a good one to choose because the patient does not have metallic fillings which can create streak artifact which can lower the quality of the model. Click on the link below to go to the file download page. Step 2: Preview the Dental CT scan file. Once you've downloaded the file you can inspect the CT scan using 3D Slicer. If you don't know about 3D Slicer, it is a free open source medical image viewing software package that can be downloaded from slicer.org. Once you have installed and opened Slicer, you can drag-and-drop the downloaded NRRD file onto the slicer window and it will open for you to view. You can see as shown in Figure 3 that the file appears to be quite good, without any dental fillings that cause streak artifact. Figure 3: Viewing the dental CT scan in Slicer. Step 3: Upload your dental CT scan NRRD file to the democratiz3D online service. Now that we are happy with our NRRD source file, we can upload it to the democratiz3D service for conversion into a 3D printable STL file. On the embodi3D website click on the democratiz3D navigation menu and Launch App, as shown in Figure 4. Figure 4: Launching the democratiz3D service. Once the online application opens, you will be asked to drag-and-drop your file onto the webpage. Go ahead and do this. Make sure that the file you are adding is an NRRD file and corresponds to a dental CT scan. An MRI will not work. This is shown in Figure 5. Figure 5: Dragging and dropping the CT scan NRRD file onto the democratiz3D application page. Step 4: Fill in basic information about your uploaded scan and generated model file While the file is uploading you can begin to fill out some of the required form fields. There are two main sections to the form. The section labeled 3 pertains to the file currently being uploaded, the NRRD file. Section 4 pertains to the generated STL file that democratiz3D will create. In Section 3 fill out a filename and a short description of your uploaded NRRD file. Specify whether you want the file to be private or shared, and whether this is a free file or a paid file that you wish to sell. You must choose a license type, although this is only really applicable if your file is shared as if it is private nobody will be able to download it. This portion of the form is shown in Figure 6. Figure 6: Filling out the submission form, part 1. Enter in information related to the uploaded NRRD file. Next proceed to section 4, the portion of the form related to the file you wish to generate. Make sure that democratiz3D processing is turned on and the slider shows green. Choose the appropriate operation. For creation of dental files, the best operation is "CT NRRD to Bone STL Detailed." This takes a CT scan in NRRD file format and converts it to a bone STL file using maximum detail. Leave the threshold at the default value of 150. Set quality to high. Make sure that you specify whether you want the file to be private or shared, and free versus paid. Make sure you specify file license. The steps are shown in Figure 7. Figure 7: Filling out the submission form, part 2. Enter in information related to the generated STL file. Make sure you check the checkbox that states you agree to the terms of use, and click the submit button. Your file will now start processing. In approximately 10 minutes or so you should receive an email stating that the file has been processed and your newly created 3D printable STL model is ready for download. The email should contain a link that will take you to your file download page, which should look something like the page in Figure 8. There should be several thumbnails which show you what the model looks like. To download the file click on the Download button. Figure 8: The file download page for your newly created dental model. Step 5: Check your dental STL file for errors and send it to your dental 3D printer! Once you have downloaded the STL file open it in Meshmixer. Meshmixer is a free 3D software program available from meshmixer.com that has many handy 3D printing related features. The democratized service is a good job of creating error-free files, but occasionally a few errors will sneak through, which can be easily fixed and Meshmixer. Click on the analysis button and then select Inspector as shown in Figure 9. Click on the Auto Repair All button and any minor defects that are remaining will be automatically fixed. Make sure to save your repaired and finalized 3D printable model by clicking on the menu File -> Export. You can now send your STL file to the 3D printer of your choice. Here is an example of the model when printed on a Form 1+ using white resin. You can see that the level of detail is very good. Formlabs has several examples of 3d printing teeth and other dental applications on their website. Thank you very much. I hope this tutorial was helpful. If you are not already a member, please consider joining the embodi3D community of medical 3D printing enthusiasts. If you have any questions or comments, please feel free to post them below.
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