This study was supported by the health Committee of Sichuan Province (Grant No.20PJ061), the National Natural Science Foundation of China (Grant No.32101188), and the General Project of Science and Technology Department of Sichuan Province (Grant No. 2021YFS0102), China.

This study did not need approval to perform or any sort of consent from the patients to use and publish their data, because all the data and information in this study and video were anonymized.
1. Collection of image data
<ol>
	<li>Scan the patient&#39;s thyroid by enhanced computerized tomography (CT) to obtain the image data in DICOM format. Ensure that this process is done within 1 week before the operation and control the slice thickness so that it is &#8804;1 mm.</li>
</ol>
2. Processing of DICOM data
<ol>
	<li>Import the scanned patient image data into the software (see Table of Materials) and set the appropriate threshold according to the difference in gray value between the thyroid gland and surrounding tissues or organs. As different gray values are reflections of differences in the density of different areas of the human body, set the grayscale threshold (unit: hu; on the software) to 226-1,500 to present the bone image; set the threshold to -200-226 to show the thyroid gland image. Let the software automatically identify the boxed area, or manually outline the boundary of the target area if the recognition is not satisfactory. 
	NOTE: Mimics automatically select the thyroid region and use the 3D region growth technology to segment the image and calculate the 3D reconstruction. At the same time, the 3D image is optimized to reduce the roughness and the sense of steps to obtain a natural, smooth, and authentic 3D digital visualization model, which enables a more straightforward observation of the 3D model for surgeons.</li>
	<li>Generate STL files from the reconstructed data model. Choose the reconstructed model in the software, click Export in the file dock, and choose STL as the exporting file format. Finally, generate the STL files successfully.</li>
</ol>
3. Medical-engineering interaction
<ol>
	<li>Send the reconstructed 3D model preview to the doctors, who will confirm the applied requirements and anatomical structure of the 3D model and give feedback to the modeling engineer if a modification is needed. After receiving confirmations from the doctors, proceed to the production preparation stage.</li>
</ol>
4. 3D printing (Supplemental File 1)
<ol>
	<li>Transfer the STL file data to the colorful material 3D printer and complete the parameter presets (such as printing mode, slice stroke thickness, support method, and model coloring) through the supporting 3D printing slicing software.
	<ol>
		<li>Select the printing model according to the type of finished products (color printing models usually use White Jet Process technology, while photosensitive resin usually uses Digital Light Procession).</li>
		<li>Select slice stroke thickness parameter according to the thickness of the products (here, from 24 &#181;m to 36 &#181;m).</li>
		<li>Choose the support method according to the fineness of the printing model: Overall support (better protection and less damage to fine details) or Partial support (which saves materials).</li>
		<li>Select model coloring using the color palette function on the printer. Unify the arteries with red color 255 and the veins with blue color 255. 
		NOTE: As other parts such as the tumor lesion are not strictly standard, surgeons can select a color according to their needs or preference.</li>
	</ol>
	</li>
	<li>Fill in hard light curing resin in the 3D printer (see Supplemental Table S1), debug the printing platform, and print using White Jet Process technology. After printing, take out the preliminary printed thyroid model. 
	&#8203;NOTE: The White Jet Process technology is based on the principle of inkjet printing, where a thin layer of photosensitive resin is printed out in one jet and then irradiated with a specific wavelength of UV light, causing a rapid polymerization reaction and curing of the photosensitive resin. This process is completed layer by layer until the print is complete.</li>
</ol>
5. Post-treatment
<ol>
	<li>Subtract the support structure of the preliminary printed thyroid model. Grind, varnish, and cure the semi-manufactured product to obtain an individualized 1:1 isometric 3D-printed thyroid model.
	<ol>
		<li>Subtracting support structure
		<ol>
			<li>Wearing gloves, break apart the wrapping supports around the preliminary model and remove most of the main body of the supporting structure.</li>
			<li>Put the model into an ultrasonic cleaner with Ca(OH)2 alkaline solution for a 15 min cleaning.</li>
			<li>Put the model into a wet sandblaster and rinse it until the rest of the support structure on the surface is washed away.</li>
		</ol>
		</li>
		<li>Grinding
		<ol>
			<li>Grind the model with an electric grinder, file, or grinding wheel.</li>
		</ol>
		</li>
		<li>Varnishing 
		NOTE: This process consists of spraying and manually painting.
		<ol>
			<li>Spray the varnish into large-area color blocks on half of the surface of the model. Manually paint the small-area color blocks with varnish.</li>
		</ol>
		</li>
		<li>Curing
		<ol>
			<li>Put the model into a UV curing machine for 30 s of curing.</li>
			<li>Take out the model and clean it with 95% alcohol. 
			NOTE: After the alcohol volatilizes completely, the production is finished.</li>
		</ol>
		</li>
	</ol>
	</li>
</ol>
6. Delivery
<ol>
	<li>Package the thyroid model and complete the delivery to the surgeons before surgery.</li>
</ol>

<ol><li>Haugen, B. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((2015+American+Thyroid+Association+management+guidelines+for+adult+patients+with+thyroid+nodules+and+differentiated+thyroid+cancer%3A+The+American+Thyroid+Association+Guidelines+Task+Force+on+thyroid+nodules+and+differentiated+thyroid+cancer%5BTitle%5D)+AND+%22Thyroid%22%5BJournal%5D)">2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer: The American Thyroid Association Guidelines Task Force on thyroid nodules and differentiated thyroid cancer.</a> Thyroid. 26 (1), 1-133 (2016).</li>
<li>Kim, Y. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+role+of+adjuvant+external+beam+radiation+therapy+for+papillary+thyroid+carcinoma+invading+the+trachea%5BTitle%5D)+AND+%22Radiation+Oncology+Journal%22%5BJournal%5D)">The role of adjuvant external beam radiation therapy for papillary thyroid carcinoma invading the trachea.</a> Radiation Oncology Journal. 35 (2), 112-120 (2017).</li>
<li>Wang, L. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Operative+management+of+locally+advanced%2C+differentiated+thyroid+cancer%5BTitle%5D)+AND+%22Surgery%22%5BJournal%5D)">Operative management of locally advanced, differentiated thyroid cancer.</a> Surgery. 160 (3), 738-746 (2016).</li>
<li>Poppe, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((MANAGEMENT+OF+ENDOCRINE+DISEASE%3A+Thyroid+and+female+infertility%3A+more+questions+than+answers%5BTitle%5D)+AND+%22European+Journal+of+Endocrinology%22%5BJournal%5D)">MANAGEMENT OF ENDOCRINE DISEASE: Thyroid and female infertility: more questions than answers.</a> European Journal of Endocrinology. 184 (4), 123-135 (2021).</li>
<li>Alexander, L. F., Patel, N. J., Caserta, M. P., Robbin, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Thyroid+ultrasound%3A+diffuse+and+nodular+disease%5BTitle%5D)+AND+%22Radiologic+Clinics+of+North+America%22%5BJournal%5D)">Thyroid ultrasound: diffuse and nodular disease.</a> Radiologic Clinics of North America. 58 (6), 1041-1057 (2020).</li>
<li>Chambers, K. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Respiratory+variation+predicts+optimal+endotracheal+tube+placement+for+intra-operative+nerve+monitoring+in+thyroid+and+parathyroid+surgery%5BTitle%5D)+AND+%22World+Journal+of+Surgery%22%5BJournal%5D)">Respiratory variation predicts optimal endotracheal tube placement for intra-operative nerve monitoring in thyroid and parathyroid surgery.</a> World Journal of Surgery. 39 (2), 393-399 (2015).</li>
<li>Ling, X. Y., Smoll, N. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+systematic+review+of+variations+of+the+recurrent+laryngeal+nerve%5BTitle%5D)+AND+%22Clinical+Anatomy%22%5BJournal%5D)">A systematic review of variations of the recurrent laryngeal nerve.</a> Clinical Anatomy. 29 (1), 104-110 (2016).</li>
<li>Qiu, K., Haghiashtiani, G., McAlpine, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((3D+printed+organ+models+for+surgical+applications%5BTitle%5D)+AND+%22Annual+Review+of+Analytical+Chemistry%22%5BJournal%5D)">3D printed organ models for surgical applications.</a> Annual Review of Analytical Chemistry. 11 (1), 287-306 (2018).</li>
<li>Tejo-Otero, A., Buj-Corral, I., Fenollosa-Artés, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((3D+printing+in+medicine+for+preoperative+surgical+planning%3A+a+review%5BTitle%5D)+AND+%22Annals+of+Biomedical+Engineering%22%5BJournal%5D)">3D printing in medicine for preoperative surgical planning: a review.</a> Annals of Biomedical Engineering. 48 (2), 536-555 (2020).</li>
<li>Jang, J., Yi, H. G., Cho, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((3D+printed+tissue+models%3A+present+and+future%5BTitle%5D)+AND+%22ACS+Biomaterials+Science+%26+Engineering%22%5BJournal%5D)">3D printed tissue models: present and future.</a> ACS Biomaterials Science & Engineering. 2 (10), 1722-1731 (2016).</li>
<li>Liaw, C. Y., Guvendiren, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Current+and+emerging+applications+of+3D+printing+in+medicine%5BTitle%5D)+AND+%22Biofabrication%22%5BJournal%5D)">Current and emerging applications of 3D printing in medicine.</a> Biofabrication. 9 (2), 024102(2017).</li>
<li>Arifin, N., Sudin, I., Ngadiman, N. H. A., Ishak, M. S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((A+comprehensive+review+of+biopolymer+fabrication+in+additive+manufacturing+processing+for+3D-tissue-engineering+scaffolds%5BTitle%5D)+AND+%22Polymers%22%5BJournal%5D)">A comprehensive review of biopolymer fabrication in additive manufacturing processing for 3D-tissue-engineering scaffolds.</a> Polymers. 14 (10), 2119(2022).</li>
<li>Li, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Inkjet+bioprinting+of+biomaterials%5BTitle%5D)+AND+%22Chemical+Reviews%22%5BJournal%5D)">Inkjet bioprinting of biomaterials.</a> Chemical Reviews. 120 (19), 10793-10833 (2020).</li>
<li>Mironov, V., Kasyanov, V., Markwald, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Organ+printing%3A+from+bioprinter+to+organ+biofabrication+line%5BTitle%5D)+AND+%22Current+Opinion+in+Biotechnology%22%5BJournal%5D)">Organ printing: from bioprinter to organ biofabrication line.</a> Current Opinion in Biotechnology. 22 (5), 667-673 (2011).</li>
<li>Niedziela, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Thyroid+nodules%5BTitle%5D)+AND+%22Best+Practice+%26+Research.+Clinical+Endocrinology+%26+Metabolism%22%5BJournal%5D)">Thyroid nodules.</a> Best Practice & Research. Clinical Endocrinology & Metabolism. 28 (2), 245-277 (2014).</li>
<li>Hong, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Usefulness+of+a+3D-printed+thyroid+cancer+phantom+for+clinician+to+patient+communication%5BTitle%5D)+AND+%22World+Journal+of+Surgery%22%5BJournal%5D)">Usefulness of a 3D-printed thyroid cancer phantom for clinician to patient communication.</a> World Journal of Surgery. 44 (3), 788-794 (2020).</li>
<li>Doucet, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Modelling+and+manufacturing+of+a+3D+printed+trachea+for+cricothyroidotomy+simulation%5BTitle%5D)+AND+%22Cureus%22%5BJournal%5D)">Modelling and manufacturing of a 3D printed trachea for cricothyroidotomy simulation.</a> Cureus. 9 (8), 1575(2017).</li>
<li>Lim, P. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Use+of+3D+printed+models+in+resident+education+for+the+classification+of+acetabulum+fractures%5BTitle%5D)+AND+%22Journal+of+Surgical+Education%22%5BJournal%5D)">Use of 3D printed models in resident education for the classification of acetabulum fractures.</a> Journal of Surgical Education. 75 (6), 1679-1684 (2018).</li>
<li>Al Ali, A. B., Griffin, M. F., Calonge, W. M., Butler, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Evaluating+the+use+of+cleft+lip+and+palate+3D-printed+models+as+a+teaching+aid%5BTitle%5D)+AND+%22Journal+of+Surgical+Education%22%5BJournal%5D)">Evaluating the use of cleft lip and palate 3D-printed models as a teaching aid.</a> Journal of Surgical Education. 75 (1), 200-208 (2018).</li>
<li>Chan, H. H. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((3D+rapid+prototyping+for+otolaryngology-head+and+neck+surgery%3A+applications+in+image-guidance%2C+surgical+simulation+and+patient-specific+modeling%5BTitle%5D)+AND+%22PLoS+One%22%5BJournal%5D)">3D rapid prototyping for otolaryngology-head and neck surgery: applications in image-guidance, surgical simulation and patient-specific modeling.</a> PLoS One. 10 (9), 0136370(2015).</li>
<li>Craft, D. F., Howell, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Preparation+and+fabrication+of+a+full-scale%2C+sagittal-sliced%2C+3D-printed%2C+patient-specific+radiotherapy+phantom%5BTitle%5D)+AND+%22Journal+of+Applied+Clinical+Medical+Physics%22%5BJournal%5D)">Preparation and fabrication of a full-scale, sagittal-sliced, 3D-printed, patient-specific radiotherapy phantom.</a> Journal of Applied Clinical Medical Physics. 18 (5), 285-292 (2017).</li>
<li>Hong, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Development+of+a+personalized+and+realistic+educational+thyroid+cancer+phantom+based+on+CT+images%3A+An+evaluation+of+accuracy+between+three+different+3D+printers%5BTitle%5D)+AND+%22Computers+in+Biology+and+Medicine%22%5BJournal%5D)">Development of a personalized and realistic educational thyroid cancer phantom based on CT images: An evaluation of accuracy between three different 3D printers.</a> Computers in Biology and Medicine. 113, 103393(2019).</li>
<li>Hazelaar, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Using+3D+printing+techniques+to+create+an+anthropomorphic+thorax+phantom+for+medical+imaging+purposes%5BTitle%5D)+AND+%22Medical+Physics%22%5BJournal%5D)">Using 3D printing techniques to create an anthropomorphic thorax phantom for medical imaging purposes.</a> Medical Physics. 45 (1), 92-100 (2018).</li>
<li>Tack, P., Victor, J., Gemmel, P., Annemans, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((3D-printing+techniques+in+a+medical+setting%3A+a+systematic+literature+review%5BTitle%5D)+AND+%22Biomedical+Engineering+Online%22%5BJournal%5D)">3D-printing techniques in a medical setting: a systematic literature review.</a> Biomedical Engineering Online. 15 (1), 115(2016).</li>
<li>Bernhard, J. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Personalized+3D+printed+model+of+kidney+and+tumor+anatomy%3A+a+useful+tool+for+patient+education%5BTitle%5D)+AND+%22World+Journal+of+Urology%22%5BJournal%5D)">Personalized 3D printed model of kidney and tumor anatomy: a useful tool for patient education.</a> World Journal of Urology. 34 (3), 337-345 (2016).</li>
</ol>

The authors declare no conflicts of interest.

Ultrasound may be the only preoperative imaging procedure for most patients undergoing thyroid surgery15. However, a few well-differentiated cases may suffer from advanced diseases, which invade the surrounding tissues or organs and hinder the operation16. This model may be more suitable for patients with far-advanced thyroid cancer. When the disease progresses, additional CT scanning is helpful for further diagnosis. This model is based on CT scanning, which provides more ...

Thyroid nodules are one of the most common endocrine diseases, among which thyroid cancer accounts for 14%-21%1. The preferred treatment for thyroid cancer is surgery. However, because the thyroid gland is located in the anterior cervical area, there are important tissues and organs close to the thyroid gland in the operation area, such as the parathyroid gland, trachea, esophagus, and cervical great vessels and nerves2,3, making the operation relatively difficult and risky. The most common surgical complications are a decrease in parathyroid function caused by parathyroid function injury or mis-resection and hoarseness caused by recurrent laryngeal nerve injury4. The reduction of the above-mentioned surgical complications has always been an objective for surgeons. The most common imaging method before thyroid surgery is ultrasound imaging, although its display of the parathyroid gland and nerve is very limited5. In addition, the variation in the position of the parathyroid gland and the recurrent laryngeal nerve in the thyroid surgery area is very high, which hinders identification6,7. If the anatomical position of each patient can be clearly displayed to the surgeon through the model in real time during the operation, it will reduce the operational risk of thyroid surgery, reduce the incidence of complications, and improve the efficiency of thyroid surgery.
In addition, it is also challenging to thoroughly explain the surgical process to patients before surgery. Some inexperienced surgeons find it difficult to explain and convey the precise details of the operation to patients, especially because of the complexity of the thyroid gland and its surrounding structures. Each patient has their own unique anatomical structure and personal needs8. Therefore, a personalized 3D thyroid model based on the real anatomy of the patient can effectively help patients and clinicians. Currently, the majority of the products on the market are mass-produced based on plane diagrams. By utilizing 3D printing technology to produce a patient-specific model that reflects each patient&#39;s individual medical needs, this model can be used to evaluate the actual condition of patients with thyroid cancer and help surgeons better communicate the nature of the disease with patients.
3D printing (or additive manufacturing) is a three-dimensional construction built from a computer aided design model or digital 3D model9. It has been used in many medical applications, such as medical devices, anatomical models, and drug formulation10. Compared to traditional imaging, a 3D printing model is more visible and more legible. Therefore, 3D printing is increasingly being used in modern surgical procedures. Commonly used 3D-printed technologies include vat polymerization-based printing, powder-based printing, inkjet-based printing, and extrusion-based printing11. In vat polymerization-based printing, a specific wavelength of light is irradiated onto a barrel of light-curing resin, which locally cures the resin one layer at a time. It has the advantages of material saving and fast printing. Powder-based printing relies on localized heating to fuse the powder material for a denser structure, but it also leads to a significant increase in printing time and cost, and is currently in limited use12. Inkjet-based printing uses a precise spraying of droplets onto the substrate in a layer-by-layer process. This technology is the most mature and has the advantages of high material compatibility, controllable cost, and fast printing time13. Extrusion-based printing extrudes materials such as solutions and suspensions through nozzles. This technique utilizes cells and, therefore, has the highest soft tissue-mimicking capabilities. Due to the higher cost and bio-affinity, it is mainly used in the field of tissue engineering and less frequently in surgical organ models14.
As a result, we chose the &#34;White Jet Process&#34; printing technology, based on the complexity of the thyroid and its surrounding structures and the surgical schedule. This technology combines the advantages of vat polymerization-based printing and inkjet-based printing, and offers high precision, fast printing, and low cost, making it a good fit for thyroid surgery. The aim of this protocol is to make a 3D-printed thyroid cancer model, improve the prognosis of patients by providing sufficient information about the anatomical structure and variation of patients, and better inform doctors and patients about all the conditions related to the surgical process.

<table><tbody><tr><td>3D color printer</td><td>Zhuhai Sina 3D Technology Co</td><td>J300PLUS</td><td>Function support: automatic optimized placement, automatic model typesetting, automatic generation support, real-time layered edge cutting and printing, slice export, custom color thickness, custom placement / scaling, man hour evaluation, material consumption evaluation, print status monitoring, material remaining display, changing materials and colors, managing work queues, full / semi enclosed printing, automatic detection of model interference, layer preview, automatic pause of ink shortage, power failure to resume printing Automatic cleaning nozzle, automatic channel adaptation, ink change, automatic cleaning pipeline, follow-up laying. Range of optional materials: RGD series transparent molding materials, RGD series opaque molding materials, FLX series soft molding materials, ABS like series molding materials, high temperature resistant molding materials, Med series molding materials (first-class medical record certification), ordinary supporting materials, water-soluble supporting materials.</td></tr><tr><td>Mimics 21.0 software&amp;nbsp;</td><td>Materialise, Belgium</td><td></td><td>DICOM data processing</td></tr></tbody></table>

a personalized 3d-printed model for preoperative evaluation in thyroid surgery

The anatomic structure of the surgical area of thyroid cancer is complex. It is very important to comprehensively and carefully evaluate the tumor location and its relation with the capsule, trachea, esophagus, nerves, and blood vessels before operation. This paper introduces an innovative 3D-printed model establishment method based on computerized tomography (CT) DICOM images. We established a personalized 3D-printed model of the cervical thyroid surgery field for each patient who needed thyroid surgery to help clinicians evaluate the key points and difficulties of the surgery and select the operation methods of key parts as a basis. The results showed that this model is conducive to preoperative discussion and the formulation of operation strategies. In particular, as a result of the clear display of the recurrent laryngeal nerve and parathyroid gland locations in the thyroid operation field, injury to them can be avoided during surgery, the difficulty of thyroid surgery reduced, and the incidence of postoperative hypoparathyroidism and complications related to recurrent laryngeal nerve injury reduced too. Moreover, this 3D-printed model is intuitive and aids communication for the signing of informed consent by patients before surgery.

This paper presents a protocol for the construction of personalized 3D-printed models of patients&#39; thyroids. Figure 1 shows a flow chart for establishing a personalized 3D-printed model for thyroids of patients. Figure 2 shows the personalized 3D-printed model printing device for thyroids of patients. Figure 3 shows the software interface for the establishment of a personalized 3D-printed model for thyroid patients. The interfac...

Watch this Scientific Journal Video about A Personalized 3D-Printed Model for Preoperative Evaluation in Thyroid Surgery at JoVE.com

A Personalized 3D-Printed Model for Preoperative Evaluation in Thyroid Surgery

Here, a new method of establishing a personalized 3D-printed model for preoperative evaluation of thyroid surgery is proposed. It is conducive to preoperative discussion, reducing the difficulty of thyroid surgery.

The anatomic structure of the surgical area of thyroid cancer is complex. It is very important to comprehensively and carefully evaluate the tumor ...

a-personalized-3d-printed-model-for-preoperative-evaluation-thyroid

Research

JoVE Journal

Medicine

1.2K Views.  Sichuan University. Here, a new method of establishing a personalized 3D-printed model for preoperative evaluation of thyroid surgery is proposed. It is conducive to preoperative discussion, reducing the difficulty of thyroid surgery.

Video: A Personalized 3D-Printed Model for Preoperative Evaluation in Thyroid Surgery

Patient-Specific Polyvinyl Alcohol Phantom Fabrication with Ultrasound and X-Ray Contrast for Brain Tumor Surgery Planning

Phantoms are essential tools for clinical training, surgical planning and the development of novel medical devices. However, it is challenging to create anatomically accurate head phantoms with realistic brain imaging properties because standard fabrication methods are not optimized to replicate any patient-specific anatomical detail and 3D printing materials are not optimized for imaging properties. In order to test and validate a novel navigation system for use during brain tumor surgery, an anatomically accurate phantom with realistic imaging and mechanical properties was required. Therefore, a phantom was developed using real patient data as input and 3D printing of molds to fabricate a patient-specific head phantom comprising the skull, brain and tumor with both ultrasound and X-ray contrast. The phantom also had mechanical properties that allowed the phantom tissue to be manipulated in a similar manner to how human brain tissue is handled during surgery. The phantom was successfully tested during a surgical simulation in a virtual operating room.
The phantom fabrication method uses commercially available materials and is easy to reproduce. The 3D printing files can be readily shared, and the technique can be adapted to encompass many different types of tumor.

This protocol describes the fabrication of a patient specific skull, brain and tumor phantom. It uses 3D printing to create molds, and polyvinyl alcohol (PVA-c) is used as the tissue mimicking material.

Phantoms are essential tools for clinical training, surgical planning and the development of novel medical devices. However, it is challenging to create ...

Bioengineering

3D Printing of Preclinical X-ray Computed Tomographic Data Sets

Three-dimensional printing allows for the production of highly detailed objects through a process known as additive manufacturing. Traditional, mold-injection methods to create models or parts have several limitations, the most important of which is a difficulty in making highly complex products in a timely, cost-effective manner.1 However, gradual improvements in three-dimensional printing technology have resulted in both high-end and economy instruments that are now available for the facile production of customized models.2 These printers have the ability to extrude high-resolution objects with enough detail to accurately represent in vivo images generated from a preclinical X-ray CT scanner. With proper data collection, surface rendering, and stereolithographic editing, it is now possible and inexpensive to rapidly produce detailed skeletal and soft tissue structures from X-ray CT data. Even in the early stages of development, the anatomical models produced by three-dimensional printing appeal to both educators and researchers who can utilize the technology to improve visualization proficiency. 3, 4 The real benefits of this method result from the tangible experience a researcher can have with data that cannot be adequately conveyed through a computer screen. The translation of pre-clinical 3D data to a physical object that is an exact copy of the test subject is a powerful tool for visualization and communication, especially for relating imaging research to students, or those in other fields. Here, we provide a detailed method for printing plastic models of bone and organ structures derived from X-ray CT scans utilizing an Albira X-ray CT system in conjunction with PMOD, ImageJ, Meshlab, Netfabb, and ReplicatorG software packages.

Using modern plastic extrusion and printing technologies, it is now possible to quickly and inexpensively produce physical models of X-ray CT data taken in a laboratory. The three -dimensional printing of tomographic data is a powerful visualization, research, and educational tool that may now be accessed by the preclinical imaging community.

Three-dimensional printing allows for the production of highly detailed objects through a process known as additive manufacturing.  Traditional, ...

Biology

Three-Dimensional Printing of a Complex Aortic Anomaly

Complex congenital aortic anomalies include diverse types of malformations that may be clinically asymptomatic or present with respiratory or esophageal symptoms. These anomalies may be associated with other congenital heart diseases. It is hard to identify the accurate anatomic vessel location from two-dimensional imaging data, such as computed tomography. As an additive manufacturing method, three-dimensional (3-D) printing can covert the acquired imaging data into 3-D physical models. This protocol describes the procedure for modeling the volumetric DICOM imaging into 3-D data and printing it as an anatomically realistic 3-D model. Using this model, surgeons can identify the vessel location of complex aortic anomalies, which is helpful for pre-operative planning and intra-operative guidance.

Here, we present a protocol to use three dimensional printed models for pre-operative planning and intra-operative reorganization of complicated vascular locations when handling a congenital aortic anomaly.

Complex congenital aortic anomalies include diverse types of malformations that may be clinically asymptomatic or present with respiratory or esophageal ...

Multicolor 3D Printing of Complex Intracranial Tumors in Neurosurgery

Three-dimensional (3D) printing technologies offer the possibility of visualizing patient-specific pathologies in a physical model of correct dimensions. The model can be used for planning and simulating critical steps of a surgical approach. Therefore, it is important that anatomical structures such as blood vessels inside a tumor can be printed to be colored not only on their surface, but throughout their whole volume. During simulation this allows for the removal of certain parts (e.g., with a high-speed drill) and revealing internally located structures of a different color. Thus, diagnostic information from various imaging modalities (e.g., CT, MRI) can be combined in a single compact and tangible object.
However, preparation and printing of such a fully colored anatomical model remains a difficult task. Therefore, a step-by-step guide is provided, demonstrating the fusion of different cross-sectional imaging data sets, segmentation of anatomical structures, and creation of a virtual model. In a second step the virtual model is printed with volumetrically colored anatomical structures using a plaster-based color 3D binder jetting technique. This method allows highly accurate reproduction of patient-specific anatomy as shown in a series of 3D-printed petrous apex chondrosarcomas. Furthermore, the models created can be cut and drilled, revealing internal structures that allow for simulation of surgical procedures.

The protocol describes the fabrication of fully colored three-dimensional prints of patient-specific, anatomical skull models to be used for surgical simulation. The crucial steps of combining different imaging modalities, image segmentation, three-dimensional model extraction, and production of the prints are explained.

Three-dimensional (3D) printing technologies offer the possibility of visualizing patient-specific pathologies in a physical model of correct dimensions. ...

Combining Augmented Reality and 3D Printing to Display Patient Models on a Smartphone

Augmented reality (AR) has great potential in education, training, and surgical guidance in the medical field. Its combination with three-dimensional (3D) printing (3DP) opens new possibilities in clinical applications. Although these technologies have grown exponentially in recent years, their adoption by physicians is still limited, since they require extensive knowledge of engineering and software development. Therefore, the purpose of this protocol is to describe a step-by-step methodology enabling inexperienced users to create a smartphone app, which combines AR and 3DP for the visualization of anatomical 3D models of patients with a 3D-printed reference marker. The protocol describes how to create 3D virtual models of a patient&rsquo;s anatomy derived from 3D medical images. It then explains how to perform positioning of the 3D models with respect to marker references. Also provided are instructions for how to 3D print the required tools and models. Finally, steps to deploy the app are provided. The protocol is based on free and multi-platform software and can be applied to any medical imaging modality or patient. An alternative approach is described to provide automatic registration between a 3D-printed model created from a patient&rsquo;s anatomy and the projected holograms. As an example, a clinical case of a patient suffering from distal leg sarcoma is provided to illustrate the methodology. It is expected that this protocol will accelerate the adoption of AR and 3DP technologies by medical professionals.

Presented here is a method to design an augmented reality smartphone application for the visualization of anatomical three-dimensional models of patients using a 3D-printed reference marker.

Augmented reality (AR) has great potential in education, training, and surgical guidance in the medical field. Its combination with three-dimensional (3D) ...

3D Planning and Printing of Patient Specific Implants for Reconstruction of Bony Defects

We are in the midst of the 3D era in most aspects of life, and especially in medicine. The surgical discipline is one of the major players in the medical field using the constantly developing 3D planning and printing capabilities. Computer-assisted design (CAD) and computer assisted manufacturing (CAM) are used to describe the 3D planning and manufacturing of the product. The planning and manufacturing of 3D surgical guides and reconstruction implants is performed almost exclusively by engineers. As technology advances and software interfaces become more user-friendly, it raises a question regarding the possibility of transferring the planning and manufacturing to the clinician. The reasons for such a shift are clear: the surgeon has the idea of what he wants to design, and he also knows what is feasible and could be used in the operating room. It allows him to be prepared for any scenario/unexpected results during the operation and allows the surgeon to be creative and express his new ideas using the CAD software. The purpose of this method is to provide clinicians with the ability to create their own surgical guides and reconstruction implants. In this manuscript, a detailed protocol will provide a simple method for segmentation using segmentation software and implant planning using a 3D design software. Following the segmentation and stl file production using segmentation software, the clinician could create a simple patient specific reconstruction plate or a more complex plate with a cradle for bone graft positioning. Surgical guides can be created for accurate resection, hole preparation for proper reconstruction plate positioning or for bone graft harvesting and re-contouring. A case of lower jaw reconstruction following plate fracture and nonunion healing of a trauma sustained injury is detailed.

This protocol describes the use of 3D planning and printing for reconstruction of bony defects. We use segmentation tools to create 3D models followed by 3D design software to create patient specific implants for reconstruction purposes concomitant to ablative surgery or as a second stage.

We are in the midst of the 3D era in most aspects of life, and especially in medicine. The surgical discipline is one of the major players in the medical ...

Development and Evaluation of 3D-Printed Cardiovascular Phantoms for Interventional Planning and Training

Catheter-based interventions are standard treatment options for cardiovascular pathologies. Therefore, patient-specific models could help training physicians&#39; wire-skills as well as improving planning of interventional procedures. The aim of this study was to develop a manufacturing process of patient-specific 3D-printed models for cardiovascular interventions.
To create a 3D-printed elastic phantom, different 3D-printing materials were compared to porcine biological tissues (i.e., aortic tissue) in terms of mechanical characteristics. A fitting material was selected based on comparative tensile tests and specific material thicknesses were defined. Anonymized contrast-enhanced CT-datasets were collected retrospectively. Patient-specific volumetric models were extracted from these datasets and subsequently 3D-printed. A pulsatile flow loop was constructed to simulate the intraluminal blood flow during interventions. Models&#39; suitability for clinical imaging was assessed by x-ray imaging, CT, 4D-MRI and (Doppler) ultrasonography. Contrast medium was used to enhance visibility in x-ray-based imaging. Different catheterization techniques were applied to evaluate the 3D-printed phantoms in physicians&#39; training as well as for pre-interventional therapy planning.
Printed models showed a high printing resolution (~30 &#181;m) and mechanical properties of the chosen material were comparable to physiological biomechanics. Physical and digital models showed high anatomical accuracy when compared to the underlying radiological dataset. Printed models were suitable for ultrasonic imaging as well as standard x-rays. Doppler ultrasonography and 4D-MRI displayed flow patterns and landmark characteristics (i.e., turbulence, wall shear stress) matching native data. In a catheter-based laboratory setting, patient-specific phantoms were easy to catheterize. Therapy planning and training of interventional procedures on challenging anatomies (e.g., congenital heart disease (CHD)) was possible.
Flexible patient-specific cardiovascular phantoms were 3D-printed, and the application of common clinical imaging techniques was possible. This new process is ideal as a training tool for catheter-based (electrophysiological) interventions and can be used in patient-specific therapy planning.

Here we present development of a mock circulation setup for multimodal therapy evaluation, pre-interventional planning, and physician-training on cardiovascular anatomies. With the application of patient-specific tomographic scans, this setup is ideal for therapeutic approaches, training, and education in individualized medicine.

Catheter-based interventions are standard treatment options for cardiovascular pathologies. Therefore, patient-specific models could help training ...

3D Printing Model of a Patient's Specific Lumbar Vertebra

Selective dorsal rhizotomy (SDR) is a difficult, risky, and sophisticated operation, in which a laminectomy should not only expose an adequate surgical field of view but also protect the patient&#39;s spinal nerves from injury. Digital models play an important role in the pre-and intra-operation of SDR, because they can not only make doctors more familiar with the anatomical structure of the surgical site, but also provide precise surgical navigation coordinates for the manipulator. This study aims to create a 3D digital model of a patient-specific lumbar vertebra that can be used for planning, surgical navigation, and training of the SDR operation. The 3D printing model is also manufactured for more effective work during these processes.
Traditional orthopedic digital models rely almost entirely on computed tomography (CT) data, which is less sensitive to soft tissues. Fusion of the bone structure from CT and the neural structure from magnetic resonance imaging (MRI) is the key element for the model reconstruction in this study. The patient&#39;s specific 3D digital model is reconstructed for the real appearance of the surgical area and shows the accurate measurement of inter-structural distances and regional segmentation, which can effectively help in the preoperative planning and training of SDR. The transparent bone structure material of the 3D-printed model allows surgeons to clearly distinguish the relative relationship between the spinal nerve and the vertebral plate of the operated segment, enhancing their anatomical understanding and spatial sense of the structure. The advantages of the individualized 3D digital model and its accurate relationship between spinal nerve and bone structures make this method a good choice for preoperative planning of SDR surgery.

This study aims to create a 3D-printed model of a patient-specific lumbar vertebra, which contains both the vertebra and spinal nerve models fused from high-resolution computed tomography (HRCT) and MRI-Dixon data.

Selective dorsal rhizotomy (SDR) is a difficult, risky, and sophisticated operation, in which a laminectomy should not only expose an adequate surgical ...

Computer-Aided Three-Dimensional Visualization in the Treatment of Locally Advanced Thyroid Cancer

The diagnosis and treatment of locally advanced thyroid carcinoma are challenging. The challenge lies in the evaluation of the tumor scope and the formulation of an individualized treatment plan. Three-dimensional (3D) visualization has a wide range of applications in the field of medicine, although there are limited applications in thyroid cancer. We previously applied 3D visualization for the diagnosis and treatment of thyroid cancer. Through data collection, 3D modeling, and preoperative evaluation, we can obtain 3D information regarding the tumor outline, determine the extent of tumor invasion, and conduct adequate preoperative preparation and surgical risk assessment. This study aimed to demonstrate the feasibility of 3D visualization in locally advanced thyroid cancer. Computer-aided 3D visualization can be an effective method for accurate preoperative evaluation, the development of surgical methods, shortening the surgical time, and reducing the surgical risks. Furthermore, it can contribute to medical education and doctor-patient communication. We believe that the application of 3D visualization technology can improve outcomes and quality of life in patients with locally advanced thyroid cancer.

In diagnosing and treating locally advanced thyroid cancer, the application of computer-aided three-dimensional reconstruction can provide additional information regarding the tumor scope and anatomic characteristics, thereby assisting in risk assessment and surgical planning.

The diagnosis and treatment of locally advanced thyroid carcinoma are challenging. The challenge lies in the evaluation of the tumor scope and the ...

Synchronous Visualization of Thyroid Structural and Functional Information

Synchronous Triplanar Reconstruction Integrated with Color Doppler Mapping for Precise and Rapid Localization of Thyroid Lesions

This paper proposes a novel thyroid examination technique based on five-dimensional (5D) synchronous reconstruction of ultrasound data. The raw temporal sequences are reconstructed into 3D volumetric data reflecting anatomical structure. Triplanar visualization from three orthogonal planes is realized to provide a systematic inspection of the entire gland. Color Doppler imaging is integrated into each triplanar slice to map vascularity changes. This multi-modal fusion enables synchronous display of structural, functional, and blood flow information in the reconstructed 5D space. Compared to conventional scanning, this technique offers the benefits of flexible offline diagnosis, reduced dependency on scanning, enhanced intuitive interpretation, and comprehensive multi-aspect evaluation. By minimizing oversight errors, it could improve diagnostic accuracy, especially for novice practitioners. The proposed 5D fusion method allows rapid and precise localization of lesions for early detection. Future work will explore integration with biochemical markers to further improve diagnostic precision. The technique has considerable clinical value for advancing thyroid examination.

Author Spotlight: Integrating Ultrasound Imaging with Biochemical Markers for Thyroid Disease Diagnosis

Here we present a 5D ultrasound technique combining multi-planar 3D reconstruction and color Doppler fusion, which enables synchronous visualization of thyroid structural and functional information. By minimizing blind spots, this method allows rapid, precise localization of lesions to improve diagnostic accuracy, especially benefiting novice practitioners.

This paper proposes a novel thyroid examination technique based on five-dimensional (5D) synchronous reconstruction of ultrasound data. The raw temporal ...