Integration of Patient-Specific Paranasal Sinus Computed Tomographic Data into a Virtual Surgical Environment

2009 ◽  
Vol 23 (4) ◽  
pp. 442-447 ◽  
Author(s):  
Sachin S. Parikh ◽  
Sonny Chan ◽  
Sumit K. Agrawal ◽  
Peter H. Hwang ◽  
Curt M. Salisbury ◽  
...  
Keyword(s):  
Haptic Feedback ◽  
Three Dimensional ◽  
Sinus Surgery ◽  
Patient Specific ◽  
Imaging Data ◽  
Cross Sectional ◽  
Endoscopic Techniques ◽  
Computed Tomographic ◽  
Preoperative Ct ◽  
Ct Data

Background The advent of both high-resolution computed tomographic (CT) imaging and minimally invasive endoscopic techniques has led to revolutionary advances in sinus surgery. However, the rhinologist is left to make the conceptual jump between static cross-sectional images and the anatomy encountered intraoperatively. A three-dimensional (3D) visuo-haptic representation of the patient's anatomy may allow for enhanced preoperative planning and rehearsal, with the goal of improving outcomes, decreasing complications, and enhancing technical skills. Methods We developed a novel method of automatically constructing 3D visuo-haptic models of patients’ anatomy from preoperative CT scans for placement in a virtual surgical environment (VSE). State-of-the-art techniques were used to create a high-fidelity representation of salient bone and soft tissue anatomy and to enable manipulation of the virtual patient in a surgically meaningful manner. A modified haptic interface device drives a virtual endoscope that mimics the surgical configuration. Results The creation and manipulation of sinus anatomy from CT data appeared to provide a relevant means of exploring patient-specific anatomy. Unlike more traditional methods of interacting with multiplanar imaging data, our VSE provides the potential for a more intuitive experience that can replicate the views and access expected at surgery. The inclusion of tactile (haptic) feedback provides an additional dimension of realism. Conclusion The incorporation of patient-specific clinical CT data into a virtual surgical environment holds the potential to offer the surgeon a novel means to prepare for rhinologic procedures and offer training to residents. An automated pathway for segmentation, reconstruction, and an intuitive interface for manipulation may enable rehearsal of planned procedures.

Accuracy of Patient-Specific 3D Printed Drill Guides in the Placement of a Canine Coxofemoral Toggle Pin through a Minimally Invasive Approach

2020 ◽  
Author(s):  
Brett G. Darrow ◽  
Kyle A. Snowdon ◽  
Adrien Hespel
Keyword(s):  
Minimally Invasive ◽  
Three Dimensional ◽  
Bone Tunnel ◽  
Patient Specific ◽  
Exit Point ◽  
Minimally Invasive Approach ◽  
Invasive Approach ◽  
Post Procedure ◽  
Drill Guide ◽  
Ct Data

Abstract Objective The aim of this study was to evaluate the accuracy of patient-specific three-dimensional printed drill guides (3D-PDG) for the placement of a coxofemoral toggle via a minimally invasive approach. Materials and Methods Pre-procedure computed tomography (CT) data of 19 canine cadaveric hips were used to design a cadaver-specific 3D-PDG that conformed to the proximal femur. Femoral and acetabular bone tunnels were drilled through the 3D-PDG, and a coxofemoral toggle pin was placed. The accuracy of tunnel placement was evaluated with post-procedure CT and gross dissection. Results Coxofemoral toggle pins were successfully placed in all dogs. Mean exit point translation at the fovea capitis was 2.5 mm (0.2–7.5) when comparing pre- and post-procedure CT scans. Gross dissection revealed the bone tunnel exited the fovea capitis inside (3/19), partially inside (12/19) and outside of (4/19) the ligament of the head of the femur. Placement of the bone tunnel through the acetabulum was inside (16/19), partially inside (1/19) and outside (2/19) of the acetabular fossa. Small 1 to 2 mm articular cartilage fragments were noted in 10 of 19 specimens. Clinical Significance Three-dimensional printed drill guide designed for coxofemoral toggle pin application is feasible. Errors are attributed to surgical execution and identification of the borders of the fovea capitis on CT data. Future studies should investigate modifications to 3D-PDG design and methods. Three-dimensional printed drill guide for coxofemoral toggle pin placement warrants consideration for use in select clinical cases of traumatic coxofemoral luxation.

Considerations for Post-processing Parameters in Mixed-Method 3D Analyses

2021 ◽  
Vol 9 (4) ◽  
pp. 325-337
Author(s):  
Robert Z. Selden ◽  
Lauren N. Butaric ◽  
Kersten Bergstrom ◽  
Dennis Van Gerven
Keyword(s):  
Three Dimensional ◽  
Processing Parameters ◽  
Surface Model ◽  
Digital Repositories ◽  
Computed Tomographic ◽  
Archaeological Data ◽  
3D Data ◽  
Morphometric Analyses ◽  
Smoothing Parameters ◽  
Ct Data

ABSTRACTThe production of three-dimensional (3D) digital meshes of surface and computed tomographic (CT) data has become widespread in morphometric analyses of anthropological and archaeological data. Given that processing methods are not standardized, this leaves questions regarding the comparability of processed and digitally curated 3D datasets. The goal of this study was to identify those processing parameters that result in the most consistent fit between CT-derived meshes and a 3D surface model of the same human mandible. Eight meshes, each using unique thresholding and smoothing parameters, were compared to assess whole-object deviations, deviations along curves, and deviations between specific anatomical features on the surface model when compared with the CT scans using a suite of comparison points. Based on calculated gap distances, the mesh that thresholded at “0” with an applied smoothing technique was found to deviate least from the surface model, although it is not the most biologically accurate. Results have implications for aggregated studies that employ multimodal 3D datasets, and caution is recommended for studies that enlist 3D data from websites and digital repositories, particularly if processing parameters are unknown or derived for studies with different research foci.

scholarly journals Main Clinical Use of Additive Manufacturing (Three-Dimensional Printing) in Finland Restricted to the Head and Neck Area in 2016–2017

2019 ◽  
Vol 109 (2) ◽  
pp. 166-173 ◽  
Author(s):  
A.B.V. Pettersson ◽  
M. Salmi ◽  
P. Vallittu ◽  
W. Serlo ◽  
J. Tuomi ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Patient Specific ◽  
Future Research ◽  
Imaging Data ◽  
University Hospitals ◽  
Three Dimensional Printing ◽  
Dimensional Printing ◽  
Head Area

Background and Aims: Additive manufacturing or three-dimensional printing is a novel production methodology for producing patient-specific models, medical aids, tools, and implants. However, the clinical impact of this technology is unknown. In this study, we sought to characterize the clinical adoption of medical additive manufacturing in Finland in 2016–2017. We focused on non-dental usage at university hospitals. Materials and Methods: A questionnaire containing five questions was sent by email to all operative, radiologic, and oncologic departments of all university hospitals in Finland. Respondents who reported extensive use of medical additive manufacturing were contacted with additional, personalized questions. Results: Of the 115 questionnaires sent, 58 received answers. Of the responders, 41% identified as non-users, including all general/gastrointestinal (GI) and vascular surgeons, urologists, and gynecologists; 23% identified as experimenters or previous users; and 36% identified as heavy users. Usage was concentrated around the head area by various specialties (neurosurgical, craniomaxillofacial, ear, nose and throat diseases (ENT), plastic surgery). Applications included repair of cranial vault defects and malformations, surgical oncology, trauma, and cleft palate reconstruction. Some routine usage was also reported in orthopedics. In addition to these patient-specific uses, we identified several off-the-shelf medical components that were produced by additive manufacturing, while some important patient-specific components were produced by traditional methodologies such as milling. Conclusion: During 2016–2017, medical additive manufacturing in Finland was routinely used at university hospitals for several applications in the head area. Outside of this area, usage was much less common. Future research should include all patient-specific products created by a computer-aided design/manufacture workflow from imaging data, instead of concentrating on the production methodology.

Computer-Assisted Surgery Using 3D Printed Saw Guides for Acute Correction of Antebrachial Angular Limb Deformities in Dogs

2019 ◽  
Vol 32 (03) ◽  
pp. 241-249 ◽  
Author(s):  
Andrew Worth ◽  
Katherine Crosse ◽  
Andrew Kersley
Keyword(s):  
Computer Aided Design ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Computer Assisted Surgery ◽  
Computer Assisted ◽  
Computed Tomographic ◽  
Limb Deformities ◽  
Ct Data ◽  
Saw Blade

Objective The aim of this study was to report the use of custom saw guides produced using computed tomographic imaging (CT), computer simulation and three-dimensional (3D) printing to aid surgical correction of antebrachial deformities in six dogs. Materials and Methods Antebrachial limb deformities in four small, and two large, breed dogs (seven limbs) were surgically corrected by a radial closing wedge ostectomy and ulnar osteotomy. The location and orientation of the wedge ostectomy were determined using CT data, computer-assisted planning and production of a saw guide in plastic using a 3D printer. At surgery, the guide was clamped to the surface of the radius and used to direct the oscillating saw blade. The resultant ostectomy was closed and stabilized with a bone plate. Results Five limbs healed without complications. One limb was re-operated due to a poorly resolved rotational component of the deformity. One limb required additional stabilisation with external fixation due to screw loosening. The owners of five dogs completed a Canine Orthopedic Index survey at a follow-up period of 37 to 81 months. The median preoperative score was 3.5 and the median postoperative score was 1, representing an overall positive effect of surgery. Radiographically, 5/7 limbs were corrected in the frontal plane (2/7 were under-corrected). Similarly, 5/7 limbs were corrected in the sagittal plane, and 2/7 were over-corrected in the sagittal place. Conclusions Computer-aided design and rapid prototyping technologies can be used to create saw guides to simplify one-stage corrective osteotomies of the antebrachium using internal fixation in dogs. Despite the encouraging results, accurate correction of rotational deformity was problematic and this aspect requires further development.

Custom Patient-Specific Three-Dimensional Printed Mitral Valve Models for Pre-Operative Patient Education Enhance Patient Satisfaction and Understanding

2019 ◽  
Vol 13 (3) ◽  
Author(s):  
Kay S. Hung ◽  
Michael J. Paulsen ◽  
Hanjay Wang ◽  
Camille Hironaka ◽  
Y. Joseph Woo
Keyword(s):  
Patient Education ◽  
Mitral Valve ◽  
Three Dimensional ◽  
3D Models ◽  
Patient Specific ◽  
Imaging Data ◽  
Anatomical Models ◽  
Mitral Valves ◽  
Flexible Polymer ◽  
3D Printed

In recent years, advances in medical imaging and three-dimensional (3D) additive manufacturing techniques have increased the use of 3D-printed anatomical models for surgical planning, device design and testing, customization of prostheses, and medical education. Using 3D-printing technology, we generated patient-specific models of mitral valves from their pre-operative cardiac imaging data and utilized these custom models to educate patients about their anatomy, disease, and treatment. Clinical 3D transthoracic and transesophageal echocardiography images were acquired from patients referred for mitral valve repair surgery and segmented using 3D modeling software. Patient-specific mitral valves were 3D-printed using a flexible polymer material to mimic the precise geometry and tissue texture of the relevant anatomy. 3D models were presented to patients at their pre-operative clinic visit and patient education was performed using either the 3D model or the standard anatomic illustrations. Afterward, patients completed questionnaires assessing knowledge and satisfaction. Responses were calculated based on a 1–5 Likert scale and analyzed using a nonparametric Mann–Whitney test. Twelve patients were presented with a patient-specific 3D-printed mitral valve model in addition to standard education materials and twelve patients were presented with only standard educational materials. The mean survey scores were 64.2 (±1.7) and 60.1 (±5.9), respectively (p = 0.008). The use of patient-specific anatomical models positively impacts patient education and satisfaction, and is a feasible method to open new opportunities in precision medicine.

scholarly journals Personalized Three-Dimensional Printed Models in Congenital Heart Disease

2019 ◽  
Vol 8 (4) ◽  
pp. 522 ◽  
Author(s):  
Sun ◽  
Lau ◽  
Wong ◽  
Yeong
Keyword(s):  
Congenital Heart Disease ◽  
Heart Disease ◽  
Congenital Heart ◽  
Three Dimensional ◽  
Patient Specific ◽  
Future Research ◽  
Imaging Data ◽  
Doctor Patient Communication ◽  
Medical Education And Training ◽  
3D Printed

Patient-specific three-dimensional (3D) printed models have been increasingly used in cardiology and cardiac surgery, in particular, showing great value in the domain of congenital heart disease (CHD). CHD is characterized by complex cardiac anomalies with disease variations between individuals; thus, it is difficult to obtain comprehensive spatial conceptualization of the cardiac structures based on the current imaging visualizations. 3D printed models derived from patient’s cardiac imaging data overcome this limitation by creating personalized 3D heart models, which not only improve spatial visualization, but also assist preoperative planning and simulation of cardiac procedures, serve as a useful tool in medical education and training, and improve doctor–patient communication. This review article provides an overall view of the clinical applications and usefulness of 3D printed models in CHD. Current limitations and future research directions of 3D printed heart models are highlighted.

Does the DSA reconstruction kernel affect hemodynamic predictions in intracranial aneurysms? An analysis of geometry and blood flow variations

2017 ◽  
Vol 10 (3) ◽  
pp. 290-296 ◽  
Author(s):  
P Berg ◽  
S Saalfeld ◽  
S Voß ◽  
T Redel ◽  
B Preim ◽  
...  
Keyword(s):  
Blood Flow ◽  
Intracranial Aneurysms ◽  
Three Dimensional ◽  
Patient Specific ◽  
Parent Artery ◽  
Imaging Data ◽  
Specific Flow ◽  
Aneurysm Neck ◽  
Velocity Magnitude ◽  
Reconstruction Kernel

BackgroundComputational fluid dynamics (CFD) blood flow predictions in intracranial aneurysms promise great potential to reveal patient-specific flow structures. Since the workflow from image acquisition to the final result includes various processing steps, quantifications of the individual introduced potential error sources are required.MethodsThree-dimensional (3D) reconstruction of the acquired imaging data as input to 3D model generation was evaluated. Six different reconstruction modes for 3D digital subtraction angiography (DSA) acquisitions were applied to eight patient-specific aneurysms. Segmentations were extracted to compare the 3D luminal surfaces. Time-dependent CFD simulations were carried out in all 48 configurations to assess the velocity and wall shear stress (WSS) variability due to the choice of reconstruction kernel.ResultsAll kernels yielded good segmentation agreement in the parent artery; deviations of the luminal surface were present at the aneurysm neck (up to 34.18%) and in distal or perforating arteries. Observations included pseudostenoses as well as noisy surfaces, depending on the selected reconstruction kernel. Consequently, the hemodynamic predictions show a mean SD of 11.09% for the aneurysm neck inflow rate, 5.07% for the centerline-based velocity magnitude, and 17.83%/9.53% for the mean/max aneurysmal WSS, respectively. In particular, vessel sections distal to the aneurysms yielded stronger variations of the CFD values.ConclusionsThe choice of reconstruction kernel for DSA data influences the segmentation result, especially for small arteries. Therefore, if precise morphology measurements or blood flow descriptions are desired, a specific reconstruction setting is required. Furthermore, research groups should be encouraged to denominate the kernel types used in future hemodynamic studies.

scholarly journals In-Office Guided Implant Placement for Prosthetically Driven Implant Surgery

2017 ◽  
Vol 10 (3) ◽  
pp. 246-254 ◽  
Author(s):  
Daryoush Karami ◽  
Hamid Reza Alborzinia ◽  
Reza Amid ◽  
Mahdi Kadkhodazadeh ◽  
Navid Yousefi ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Direct Observation ◽  
Three Dimensional ◽  
Hard Tissue ◽  
Tissue Thickness ◽  
Computed Tomographic ◽  
Implant Placement ◽  
Soft Tissue Thickness ◽  
Ct Data ◽  
The Cost

Application of surgical stents for implant placement via guided flapless surgery is increasing. However, high cost, need for some professional machines, and not taking into account the soft-tissue parameters have limited their application. We sought to design and introduce a technique named in-office guided implant placement (iGIP) to decrease the cost by using available devices in office and enhance the applicability of surgical stents. A customized surgical stent was fabricated based on prosthetic, soft- and hard-tissue parameters by taking into account the amount of available bone (using the computed tomographic [CT] data), soft-tissue thickness and contour (using a composite-covered radiographic stent), and position of the final crown (by diagnostic cast wax up and marking the final crown position with composite). The efficacy of iGIP, in terms of the accuracy of the three-dimensional position of the implant placed in the study cast and in patient's mouth, was confirmed by direct observation and postoperative CT. The iGIP can enhance implant placement in the prosthetically desired position in various types of edentulism. Using this technique minimizes the risk of unwanted consequences, as the soft-tissue thickness and contour are taken into account when fabricating a surgical stent.

scholarly journals Boundary conditions of patient-specific fluid dynamics modelling of cavopulmonary connections: possible adaptation of pulmonary resistances results in a critical issue for a virtual surgical planning

2011 ◽  
Vol 1 (3) ◽  
pp. 297-307 ◽  
Author(s):  
Giancarlo Pennati ◽  
Chiara Corsini ◽  
Daria Cosentino ◽  
Tain-Yen Hsia ◽  
Vincenzo S. Luisi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Boundary Conditions ◽  
Three Dimensional ◽  
Critical Issue ◽  
Patient Specific ◽  
Imaging Data ◽  
Venae Cavae ◽  
Cavopulmonary Anastomosis ◽  
Operative Planning ◽  
The Right

Cavopulmonary connections are surgical procedures used to treat a variety of complex congenital cardiac defects. Virtual pre-operative planning based on in silico patient-specific modelling might become a powerful tool in the surgical decision-making process. For this purpose, three-dimensional models can be easily developed from medical imaging data to investigate individual haemodynamics. However, the definition of patient-specific boundary conditions is still a crucial issue. The present study describes an approach to evaluate the vascular impedance of the right and left lungs on the basis of pre-operative clinical data and numerical simulations. Computational fluid dynamics techniques are applied to a patient with a bidirectional cavopulmonary anastomosis, who later underwent a total cavopulmonary connection (TCPC). Multi-scale models describing the surgical region and the lungs are adopted, while the flow rates measured in the venae cavae are used at the model inlets. Pre-operative and post-operative conditions are investigated; namely, TCPC haemodynamics, which are predicted using patient-specific pre-operative boundary conditions, indicates that the pre-operative balanced lung resistances are not compatible with the TCPC measured flows, suggesting that the pulmonary vascular impedances changed individually after the surgery. These modifications might be the consequence of adaptation to the altered pulmonary blood flows.

CT Artifacts of the Proximal Aortic Neck: An Important Problem in Endograft Planning

2002 ◽  
Vol 9 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Boonprasit Kritpracha ◽  
Jeremy Wolfe ◽  
Hugh G. Beebe
Keyword(s):  
Statistical Significance ◽  
Three Dimensional ◽  
Vessel Diameter ◽  
Maximum Diameter ◽  
Computed Tomographic ◽  
Aortic Neck ◽  
Preoperative Ct ◽  
Axial Ct ◽  
Ct Slices ◽  
Reformatted Ct

Purpose: To describe the imaging error introduced by noncircular abdominal aortic aneurysm (AAA) necks in axial and reformatted computed tomographic (CT) images and discuss the potential implications for aortic endografting. Methods: The records of 120 endograft patients with preoperative CT axial scans and subsequent 3-dimensional (3D) computerized reconstructions were reviewed. Maximum and minimum infrarenal aortic neck diameters were measured from axial CT scans and 3D reformatted slices at the same point on the vessel. Diameter measurements were made at the largest point within the 10-mm segment of vessel below the lowest renal artery. Excluded were aneurysms with proximal neck minimum diameters >30 mm, neck lengths <15 mm, or angulation >75° measured on the axial CT slice. Results: Measuring from reformatted CT slices, 86 (71.6%) cases had ≤2-mm differences between maximal and minimal neck diameters, comprising the “round neck” group A. In 34 (28.4%) cases, the neck was not round: 26 (21.7%) had diameter differences between 2 and 4 mm (group B) and 8 (6.7%) had a >4-mm difference (group C; range 4.1–8.1 mm). Although AAA diameter, neck length, and neck angle progressively increased as the difference between neck maximum and minimum diameters grew, i.e., greater eccentricity, these trends did not reach statistical significance. Mean infrarenal neck maximum diameter was significantly larger in group C (30.2 ± 3.4 mm) compared to groups A (23.0 ± 2.9 mm, p = 0.0002) and B (23.8 ± 3.6 mm, p = 0.0003). Hence, 28.4% of AAAs had a noncircular aortic neck of varying degree, and 6.7% had an eccentricity factor that may have clinical significance. Conclusions: This study confirms the importance of selecting an endoprosthesis sized 15% to 20% larger than the infrarenal aortic neck diameter. Three-dimensional reconstruction using reformatted CT slices perpendicular to the flow lumen is an important tool that offers enhanced accuracy of infrarenal aortic neck evaluation.

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