This publication was supported by the Beijing Municipal Natural Science Foundation (L192059).

All data come from the clinical patient, whose SDR operation was carried out at BJ Dongzhimen Hospital. The protocol follows the guidelines of and was approved by the Dongzhimen Hospital research ethics committee.
NOTE: The whole map of the model reconstruction protocol is shown in Figure 1. The high-resolution computed tomography (HRCT) data and Dixon data are raw materials for modeling; then, the 3D model creation consists of image registration and fusion. The final 3D digital model is printed by PolyJet technology which is a high-precision 3D printing process that produces smooth and accurate parts using a wide range of materials. In order to describe the spatial relationship between the vertebra and spinal nerve exactly, HRCT data and Dixon image series are used. The Dixon scanning can identify water and fat separation images, in which the Dixon water phase image series can be used to extract the structure of the spinal nerves, and the Dixon-in phase image series can be used to check the registration of the bone structure.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/65093/65093fig01.jpg" /> 
Figure 1: The whole map of the protocol. The research methodology of this study involves the fusion of CT and magnetic resonance Dixon sequences. Specifically, the CT vertebrae structure is registered with the identical vertebrae structure contained in the Dixon-in sequence, followed by fusion with the Dixon-w sequence for the spinal nerve. <a href="https://www.jove.com/files/ftp_upload/65093/65093fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
1. Data collection and preparation
<ol>
	<li>High-resolution CT for vertebrae 
	NOTE: The parameter difference is not sensitive to the research method.
	<ol>
		<li>Set the data resources from the CT machine station. 
		NOTE: Here, the SIEMENS-CTAWP73396 CT machine is used.</li>
		<li>Open the Syngo CT 2012B software to receive data from the scanning protocol SpineRoutine_1. Select the Pixel Size and Slice Thickness (ST) of the dataset to adapt to the size of the vertebrae intended to be represented in the 3D digital model.</li>
		<li>Use an ST of 1 mm with a matrix size of 512 pixels x 512 pixels, in which the pixel spacing is 0.3320 mm. The actual size of the 3D volume achieved is 512 x 512 x 204 voxels.</li>
	</ol>
	</li>
	<li>Dixon sequence for spinal nerve 
	&#8203;NOTE: A 1.5 T MRI machine is used in this study.
	<ol>
		<li>Set the Dixon image Resolution as 290 pixels x 320 pixels, Pixel Spacing as 0.9375 mm, and Slice Thickness as 3 mm to obtain accurate data.</li>
		<li>Set the Repetition Time as 5,160 ms and the Echo Time as 94 ms.</li>
		<li>Ensure every scanned layer consists of four-phase images, which are Dixon-in, Dixon-opp, Dixon-F, and Dixon-w.</li>
	</ol>
	</li>
	<li>Prepare data-storing files for model reconstruction. 
	NOTE: A well-defined data-storing structure is more convenient for follow-up work.
	<ol>
		<li>Make a project folder to contain all the data belonging to the patient.</li>
		<li>Prepare different file paths for HRCT and MRI-Dixon data by making different folders for the digital imaging and communications in medicine (DICOM) data.</li>
		<li>Make a separate folder under the project for all analysis results.</li>
	</ol>
	</li>
</ol>
2. The 3D digital vertebrae model
NOTE: All subprocess functions come from software tools, whose property belongs to Beijing Intelligent Entropy Science &#38; Technology Co Ltd.
<ol>
	<li>Call the Dicom2Mat subprocess in the MATLAB workplace to obtain the 3D volume from the DICOM files stored in the HRCT data folder.</li>
	<li>After undergoing the Dicom2Mat subprocess, view each slice within the 3D volume through the graphical user interface (GUI), as depicted in Figure 2.</li>
	<li>Then, visualize the intensity distribution of the vertebrae HRCT data by the hist function (Figure 3).</li>
	<li>Call the NoiseClean subprocess to delete signal noise formed by the device under the HRCT data file paths.</li>
	<li>Use the Vertebrae function subprocess under the same path to gain the vertebrae model, which is also a 3D volume but only with the bone structure (Figure 4). The high-pass filter parameters, the intensity ranging from 190 to 1,656.</li>
</ol>
3. The 3D digital spinal nerve model
NOTE: Dixon-in contains bone structure, while Dixon-w describes neural structure.
<ol>
	<li>Use the Dicom2Mat subprocess in both paths of the Dixon-in and Dixon-w sequences and get their 3D volume.</li>
	<li>Furthermore, visualize each individual slice that constitutes a 3D volume using the GUI presented in Figure 5. Access this visualization once the Dicom2Mat subprocess has been completed.</li>
	<li>Use the Spinal_Nerve function to reconstruct the spinal nerve model with high-pass filter parameters, the intensity ranging from 180 to 643. Because the signals of the nerve in the Dixon-w sequence are very high, extract the spinal nerve 3D volume by filtering out points with low intensity.</li>
	<li>When the Spinal_Nerve subprocess is finished, check the model generated in the GUI shown in Figure 6.</li>
</ol>
4. Registration and fusion
NOTE: The key insight is that bone architecture is present in both HRCT and Dixon-in imaging sequence.
<ol>
	<li>Copy the three 3D volumes obtained so far to the file path of the project made in step 3.1. The models from HRCT and Dixon-in include the same vertebrae structure, and the models from Dixon-in and Dixon-w have the same coordinates.</li>
	<li>Then, put the three models&#39; filenames into the vertebra_fusion subprocess as an input to generate the fusion model. This can be visualized in Figure 7.</li>
	<li>The fusion is usually well done. If fine-tuning is necessary from the doctor&#39;s perspective, add coordinate parameters in all directions to the same function to correct the fusion model. If slight errors are observed in fusion from a clinical perspective, use the vertebra_fusion function to fine-tune the fusion coordinates. This process involves parameter adjustments to the six dimensions of coordinate direction (XYZ coordinates and their rotation).</li>
	<li>Make a separate folder in the project directory for outputting the result of the fusion model.</li>
</ol>
5. Digital model files for 3D printing
NOTE: A fully-developed 3D printing apparatus is utilized for the manufacturing of the aforementioned digital model, with the implementation of Delaunay triangulations. Here, the Stratasys J55 Prime 3D printer was used.
<ol>
	<li>Export the fusion models to be used for 3D printing in the DICOM format sequences under the file path of the fusion directory. Utilize the Mat2Dicom algorithm to execute the export operation by inputting the fusion model.</li>
	<li>Open the DICOM file sequence exported previously using Materialise Mimics V20. To perform the export operation, navigate to the Export menu under the File tab and select the VRML format. The file path for the export can be freely customized according to the user&#39;s requirements.</li>
	<li>As transparent colorful 3D printing is a professional service, compress and pack the VRML files and send them to the service provider. The 3D printing result is shown in Figure 8.</li>
</ol>

<ol>
	<li>Rosenbaum, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+report:+the+definition+and+classification+of+cerebral+palsy+April+2006.">A report: the definition and classification of cerebral palsy April 2006.</a> Developmental Medicine and Child Neurology. Supplement. 109, 8-14 (2007).</li><li>Krigger, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+palsy:+an+overview.">Cerebral palsy: an overview.</a> American Family Physician. 73 (1), 91-100 (2006).</li><li>Davidson, B., Fehlings, D., Milo-Manson, G., Ibrahim, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improving+access+to+selective+dorsal+rhizotomy+for+children+with+cerebral+palsy.">Improving access to selective dorsal rhizotomy for children with cerebral palsy.</a> Canadian Medical Association Journal. 191 (44), E1205-E1206 (2019).</li><li>Buizer, A. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+dorsal+rhizotomy+in+children+with+cerebral+palsy.">Selective dorsal rhizotomy in children with cerebral palsy.</a> The Lancet. Child &amp; Adolescent Health. 3 (7), 438-439 (2019).</li><li>Wong, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D-printed+patient-specific+applications+in+orthopedics.">3D-printed patient-specific applications in orthopedics.</a> Orthopedic Research and Reviews. 8, 57-66 (2016).</li><li>Wong, K. C., Kumta, S. M., Geel, N. V., Demol, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-step+reconstruction+with+a+3D-printed,+biomechanically+evaluated+custom+implant+after+complex+pelvic+tumor+resection.">One-step reconstruction with a 3D-printed, biomechanically evaluated custom implant after complex pelvic tumor resection.</a> Computer Aided Surgery. 20 (1), 14-23 (2015).</li><li>Zhu, R., Li, X., Zhang, X., Ma, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MRI+and+CT+medical+image+fusion+based+on+synchronized-anisotropic+diffusion+model.">MRI and CT medical image fusion based on synchronized-anisotropic diffusion model.</a> IEEE Access. 8, 91336-91350 (2020).</li><li>Park, T. S., Gaffney, P. E., Kaufman, B. A., Molleston, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+lumbosacral+dorsal+rhizotomy+immediately+caudal+to+the+conus+medullaris+for+cerebral+palsy+spasticity.">Selective lumbosacral dorsal rhizotomy immediately caudal to the conus medullaris for cerebral palsy spasticity.</a> Neurosurgery. 33 (5), 929-934 (1993).</li><li>Sindou, M., Georgoulis, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Keyhole+interlaminar+dorsal+rhizotomy+for+spastic+diplegia+in+cerebral+palsy.">Keyhole interlaminar dorsal rhizotomy for spastic diplegia in cerebral palsy.</a> Acta Neurochirurgica. 157 (7), 1187-1196 (2015).</li><li>Peacock, W. J., Staudt, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+posterior+rhizotomy:+evolution+of+theory+and+practice.">Selective posterior rhizotomy: evolution of theory and practice.</a> Pediatric Neurosurgery. 17 (3), 128-134 (1991).</li><li>Vitrikas, K., Dalton, H., Breish, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cerebral+palsy:+an+overview.">Cerebral palsy: an overview.</a> American Family Physician. 101 (4), 213-220 (2020).</li><li>Niikura, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tactile+surgical+navigation+system+for+complex+acetabular+fracture+surgery.">Tactile surgical navigation system for complex acetabular fracture surgery.</a> Orthopedics. 37 (4), 237-242 (2014).</li><li>Lepisto, J., Armand, M., Armiger, R. 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The digital models in this study are reconstructed by co-author Fangliang Xing.

This study provides a workflow for establishing a preoperative 3D printing model of the lumbar spine in patients with cerebral palsy, with the aim of facilitating preoperative planning for SDR surgery and enhancing anatomical training based on the patient's specific model. The study aims to establish a highly reliable 3D-printed model that accurately demonstrates the patient's lumbar vertebral and nerve structures. By measuring the position of the lamina and spinal nerve in the model before surgery, precise planning of t...

Spastic cerebral palsy affects over half of all children with cerebral palsy1, leading to tendon contractures, abnormal skeletal development, and decreased mobility, greatly impacting the quality of life of affected children2. As the main surgical method for the treatment of spastic cerebral palsy, selective dorsal rhizotomy (SDR) has been fully validated and recommended by many countries3,4. However, the intricate and high-risk nature of SDR surgery, including the precise cutting of the lamina, positioning and dissociation of nerve roots, and severing of nerve fibers, presents a significant challenge for young doctors who are just beginning to engage with SDR in clinical practice; further, the learning curve of SDR is very steep.
In traditional orthopedic surgery, surgeons must mentally integrate all preoperative two-dimensional (2D) images and create a 3D surgical plan5. This approach is particularly difficult for preoperative planning involving complex anatomical structures and surgical manipulations, such as SDR. With advances in medical imaging and computer technology, 2D axial images, such as computed tomography (CT) and magnetic resonance imaging (MRI) can be processed to create 3D virtual models with patient-specific anatomy6. With improved visualization, surgeons can analyze this processed information to make more detailed diagnoses, planning, and surgical interventions tailored to the patient&#39;s condition. In recent years, the application of multimodal image fusion technology in orthopedics has gradually attracted attention7. This technology could fuse CT and MRI images, greatly improving the accuracy of the digital3D analog model. However, the application of this technique in preoperative models of SDR has not been researched yet.
Accurate positioning of the lamina and spinal nerve and precise cutting during SDR surgery are crucial for successful outcomes. Typically, these tasks rely on experts&#39; experience and are confirmed repeatedly by a C-arm during the operation, resulting in a complex and time-consuming surgical process. The 3D digital model serves as the foundation for future SDR surgical navigation and can also be utilized for preoperative planning of laminectomy procedures.&#160;This model fuses the bone structure from CT and the spinal nerve structure from MRI, and assigns different colors to the lumbar vertebra sections marked for cutting according to the surgical plan. Such holographic 3D printing models for SDR not only facilitate preoperative planning and simulation, but also output accurate 3D navigation coordinates to the intraoperative robotic arm for precise cutting.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>J55 Prime 3D-Printer</td>
			<td>Stratasys</td>
			<td>J55 Prime</td>
			<td>Manufacturing the model</td>
		</tr>
		<tr>
			<td>MATLAB</td>
			<td>MathWorks&#160;</td>
			<td>2022B</td>
			<td>Computing and visualization&#160;</td>
		</tr>
		<tr>
			<td>Mimics</td>
			<td>Materialise</td>
			<td>Mimics Research V20</td>
			<td>Model format transformation</td>
		</tr>
		<tr>
			<td>Tools for volum fusion</td>
			<td>Intelligent Entropy</td>
			<td>VolumeFusion V1.0</td>
			<td>Beijing Intelligent Entropy Science &#38; Technology Co Ltd. 
			Modeling for CT/MRI fusion</td>
		</tr>
	</tbody>
</table>

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.

Based on lumbar CT/MRI image fusion data in children with cerebal palsy, we created a representative model of the lumbar spine combined with spinal nerves. High-pass filtering was used to extract the high signal in the CT value range of 190-1,656 from HRCT, so as to achieve the reconstruction of the bone structure of the lumbar spine in the operation area. Spinal nerve structures were reconstructed by the high-pass filtering of Dixon-w sequences in MRI. The digital model and point cloud data coordinates of the lumbar ver...

Watch this Scientific Journal Video about 3D Printing Model of a Patient's Specific Lumbar Vertebra at JoVE.com

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

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 ...

3d-printing-model-of-a-patient-s-specific-lumbar-vertebra

Research

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Medicine

1.7K Views.  Beijing University of Chinese Medicine. 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.

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

3D-Neuronavigation In Vivo Through a Patient's Brain During a Spontaneous Migraine Headache

A growing body of research, generated primarily from MRI-based studies, shows that migraine appears to occur, and possibly endure, due to the alteration of specific neural processes in the central nervous system. However, information is lacking on the molecular impact of these changes, especially on the endogenous opioid system during migraine headaches, and neuronavigation through these changes has never been done. This study aimed to investigate, using a novel 3D immersive and interactive neuronavigation (3D-IIN) approach, the endogenous &#181;-opioid transmission in the brain during a migraine headache attack in vivo. This is arguably one of the most central neuromechanisms associated with pain regulation, affecting multiple elements of the pain experience and analgesia. A 36 year-old female, who has been suffering with migraine for 10 years, was scanned in the typical headache (ictal) and nonheadache (interictal) migraine phases using Positron Emission Tomography (PET) with the selective radiotracer [11C]carfentanil, which allowed us to measure &#181;-opioid receptor availability in the brain (non-displaceable binding potential - &#181;OR BPND). The short-life radiotracer was produced by a cyclotron and chemical synthesis apparatus on campus located in close proximity to the imaging facility. Both PET scans, interictal and ictal, were scheduled during separate mid-late follicular phases of the patient's menstrual cycle. During the ictal PET session her spontaneous headache attack reached severe intensity levels; progressing to nausea and vomiting at the end of the scan session. There were reductions in &#181;OR BPND in the pain-modulatory regions of the endogenous &#181;-opioid system during the ictal phase, including the cingulate cortex, nucleus accumbens (NAcc), thalamus (Thal), and periaqueductal gray matter (PAG); indicating that &#181;ORs were already occupied by endogenous opioids released in response to the ongoing pain. To our knowledge, this is the first time that changes in &#181;OR BPND during a migraine headache attack have been neuronavigated using a novel 3D approach. This method allows for interactive research and educational exploration of a migraine attack in an actual patient's neuroimaging dataset.

3D-Neuronavigation In Vivo Through a Patient&#039;s Brain During a Spontaneous Migraine Headache

In this study, the authors report for the first time a novel 3D-Immersive &#38; Interactive Neuronavigation (3D-IIN) through the impact of a spontaneous migraine headache attack in the &#956;-opioid system of a patient's brain in vivo.

A growing body of research, generated primarily from MRI-based studies, shows that migraine appears to occur, and possibly endure, due to the alteration ...

Ovine Lumbar Intervertebral Disc Degeneration Model Utilizing a Lateral Retroperitoneal Drill Bit Injury

Intervertebral disc degeneration is a significant contributor to the development of back pain and the leading cause of disability worldwide. Numerous animal models of intervertebral disc degeneration have been developed. The ideal animal model should closely mimic the human intervertebral disc with regard to morphology, biomechanical properties and the absence of notochordal cells. The sheep lumbar intervertebral disc model fulfils these criteria. We present an ovine model of intervertebral disc degeneration utilizing a drill bit injury through a lateral retroperitoneal approach. The lateral approach significantly reduces the incision and potential morbidity associated with the traditional anterior approach to the ovine spine. Utilization of a drill-bit method of injury affords the ability to produce a consistent and reproducible injury, of precise dimensions, that initiates a consistent degree of intervertebral disc degeneration. The focal nature of the annular and nucleus pulposus defect more closely mimics the clinical condition of focal intervertebral disc herniation. Sheep recover rapidly following this procedure and are typically mobile and eating within the hour. Intervertebral disc degeneration ensues and sheep undergo necropsy and subsequent analysis at periods from eight weeks. We believe that the drill bit injury model of intervertebral disc degeneration offers advantages over more conventional annular injury models.

Intervertebral disc degeneration is a significant contributor to back pain and a leading cause of disability worldwide. Numerous animal models of intervertebral disc degeneration exist. We demonstrate an ovine model of intervertebral disc degeneration, utilizing a drill bit, which achieves a consistent disc injury and reproducible level of disc degeneration.

Intervertebral disc degeneration is a significant contributor to the development of back pain and the leading cause of disability worldwide. Numerous ...

A Mobile Outside-in Technique of Transforaminal Lumbar Endoscopy for Lumbar Disc Herniations

Percutaneous endoscopic transforaminal lumbar discectomy (PETLD) has now become a standard of care for the management of lumbar disc disease. There are two techniques for the introduction of a working cannula with respect to disc&#8212;outside-in and inside-out. The aim of this prospective study is to describe the technical aspects of a novel mobile outside-in method in dealing with different types of disc prolapse. A total of 184 consecutive patients with unilateral lower limb radiculopathy due to lumbar disc prolapse were operated on with the mobile outside-in technique of PETLD. Their clinical outcomes were evaluated based on the type of disc prolapse they had, a visual analog scale (VAS) leg pain score, the Oswestry Disability Index (ODI), and the Macnab criteria. The completeness of the decompression was documented with a postoperative magnetic resonance imaging. The mean age of the patients was 50 &#177; 16 years and the male/female ratio was 2:1. The mean follow-up was 19 &#177; 6 months. A total of 190 lumbar levels were operated on (L1&#8211;L2: n = 4, L2&#8211;L3: n = 17, L3&#8211;L4: n = 27, L4&#8211;5: n = 123, and L5&#8211;S1: n = 19). Divided into types, the patient distribution was central: n = 14, paracentral: n = 74, foraminal: n = 28, far lateral: n = 13, superior-migrated: n = 8, inferior migrated: n = 38, and high canal compromise: n = 9. The mean operative time was 35 &#177; 12 (25 - 56) min and the mean hospital stay was 1.2 &#177; 0.5 (1&#8211;3) days. The VAS score for leg pain improved from 7.5 &#177; 1 to 1.7 &#177; 0.9. The ODI improved from 70 &#177; 8.3 to 23 &#177; 5. According to the Macnab criteria, 75 patients (40.8%) had excellent results, 104 patients (56.5%) had good results, and 5 patients (2.7%) had fair results. Recurrence (including early and late) was seen in 15 out of the 190 levels that were operated on (7.89%). This article presents a novel outside-in approach that relies on a precise landing within the foramen in a mobile manner and does not solely depend upon the enlargement of the foramen. It is more versatile in application and useful in the management of all types of disc prolapse, even in severe canal compromise and high migration.

Here we present a protocol of a novel outside-in technique of transforaminal endoscopic discectomy for lumbar disc herniations. The technical aspects of the technique, the wide indications of use, and the results of the treatment in 184 patients are described in detail.

Percutaneous endoscopic transforaminal lumbar discectomy (PETLD) has now become a standard of care for the management of lumbar disc disease. There are ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

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 ...

Treatment of Facial Deformities using 3D Planning and Printing of Patient-Specific Implants

Technological advancements in surgical planning and patient-specific implants are constantly evolving. One can either adopt the technology to achieve better results, even in the less experienced hand, or continue without it. As technology develops and becomes more user-friendly, we believe it is time to allow the surgeon the option to plan his/her operations and create his/her own patient-specific surgical guides and fixation plates allowing him full control over the process. We present here a protocol for 3D planning of the operation followed by 3D planning and printing of surgical guides and patient-specific fixation implants. During this process we use two commercial computer-assisted design (CAD) software. We also use a fused deposition&#160;modeling printer for the surgical guides and a selective laser sintering printer for the titanium patient-specific fixation implants. The process includes computed tomography (CT) imaging acquisition, 3D segmentation of the skull and facial bones from the CT, 3D planning of the operations, 3D planning of patient-specific fixation implant according to the final position of the bones, 3D planning of surgical guides for performing an accurate osteotomy and preparing the bone for the fixation plates, and 3D printing of the surgical guides and the patient-specific fixation plates. The advantages of the method include full control over the surgery, planned osteotomies and fixation plates, significant reduction in price, reduction in operation duration, superior performance and highly accurate results. Limitations include the need to master the CAD programs.

As technology develops and becomes more user-friendly, planning of operations and patient-specific surgical guides and fixation plates should be performed by the surgeon. We present a protocol for 3D planning of orthognathic skeletal movements and 3D planning and printing of patient-specific fixation plates and surgical guides.

Technological advancements in surgical planning and patient-specific implants are constantly evolving. One can either adopt the technology to achieve ...

Creation of a High-Fidelity, Low-Cost, Intraosseous Line Placement Task Trainer via 3D Printing

The description of procedural task trainers includes their use as a training tool to hone technical skills through repetition and rehearsal of procedures in a safe environment before ultimately performing the procedure on a patient. Many procedural task trainers available to date suffer from several drawbacks, including unrealistic anatomy and the tendency to develop user-created &#39;landmarks&#39; after the trainer tissue undergoes repeated manipulations, potentially leading to inappropriate psychomotor skill development. To ameliorate these drawbacks, a process was created to produce a high-fidelity procedural task trainer, created from anatomy obtained from computed tomography (CT) scans, that utilize ubiquitous three-dimensional (3D) printing technology and off-the-shelf commodity supplies.
This method includes creating a 3D printed tissue mold capturing the tissue structure surrounding the skeletal element of interest to encase the bony skeletal structure suspended within the tissue, which is also 3D printed. A tissue medium mixture, which approximates tissue in both high-fidelity geometry and tissue density, is then poured into a mold and allowed to set. After a task trainer has been used to practice a procedure, such as intraosseous line placement, the tissue media, molds, and bones are reclaimable and may be reused to create a fresh task trainer, free of puncture sites and manipulation defects, for use in subsequent training sessions.

We describe a procedure to process computed tomography (CT) scans into high-fidelity, reclaimable, and low-cost procedural task trainers. The CT scan identification processes, export, segmentation, modeling, and 3D printing are all described, along with the issues and lessons learned in the process.

The description of procedural task trainers includes their use as a training tool to hone technical skills through repetition and rehearsal of procedures ...