Three-dimensional Reconstruction of the Knee for Ligament Reconstruction

Kim, Sung-Hwan,Ha, Seung-Joo 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.1

As computer technology develops and this is applied to medical image field, three dimensional image reconstruction technology using computer simulation is utilized in various categories that include anatomical study and biomechanics study of human body. Especially orthopedic surgeons are able to investigate biomechanical function and be provided information for operations with this technology in terms of ligament reconstruction of knee. And this technology can be utilized in preparing preoperative planning and instructions and training. This review is about three dimensional image reconstruction technology which is utilized in ligament reconstruction of knee.

Automatic Liver Segmentation on Abdominal Contrast-enhanced CT Images for the Pre-surgery Planning of Living Donor Liver Transplantation

Jang, Yujin,Hong, Helen,Chung, Jin Wook 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.1

Purpose For living donor liver transplantation, liver segmentation is difficult due to the variability of its shape across patients and similarity of the density of neighbor organs such as heart, stomach, kidney, and spleen. In this paper, we propose an automatic segmentation of the liver using multi-planar anatomy and deformable surface model in portal phase of abdominal contrast-enhanced CT images. Method Our method is composed of four main steps. First, the optimal liver volume is extracted by positional information of pelvis and rib and by separating lungs and heart from CT images. Second, anisotropic diffusing filtering and adaptive thresholding are used to segment the initial liver volume. Third, morphological opening and connected component labeling are applied to multiple planes for removing neighbor organs. Finally, deformable surface model and probability summation map are performed to refine a posterior liver surface and missing left robe in previous step. Results All experimental datasets were acquired on ten living donors using a SIEMENS CT system. Each image had a matrix size of $512{\times}512$ pixels with in-plane resolutions ranging from 0.54 to 0.70 mm. The slice spacing was 2.0 mm and the number of images per scan ranged from 136 to 229. For accuracy evaluation, the average symmetric surface distance (ASD) and the volume overlap error (VE) between automatic segmentation and manual segmentation by two radiologists are calculated. The ASD was $0.26{\pm}0.12mm$ for manual1 versus automatic and $0.24{\pm}0.09mm$ for manual2 versus automatic while that of inter-radiologists was $0.23{\pm}0.05mm$. The VE was $0.86{\pm}0.45%$ for manual1 versus automatic and $0.73{\pm}0.33%$ for manaual2 versus automatic while that of inter-radiologist was $0.76{\pm}0.21%$. Conclusion Our method can be used for the liver volumetry for the pre-surgery planning of living donor liver transplantation.

Clinical Application of Three-Dimensional Reconstruction in Shoulder Surgeries

Kim, Sung-Hwan,Ha, Seung-Joo 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.2

3-D medical image reconstruction technique using computer simulation technology has been used in the knowledge of the anatomical features and the biomechanical characteristics with the advancement of computer hardware and software. Especially, the use of 3-D image reconstruction technique in orthopaedics demonstrates that this technique is useful to improve surgical technique as well as to help inform the knowledge of shoulder joint anatomy. The purpose of this article is to introduce the utilization of 3-D image technology in shoulder surgeries.

Application of 3D Simulation Surgery to Orthognathic Aurgery : A Preliminary Case Study

Lim, Jung-Hwan,Kim, Hyun-Young,Jung, Young-Soo,Jung, Hwi-Dong 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.1

The aim of this report is to evaluate accuracy using3D surgical simulationand digitally printedwafer in orthognathic surgery. 22-year-old female was diagnosed with mandibular prognathism and apertognathia based on 3D diagnosis using CT. Digital dentition images were taken by laser scanning from dental cast, and each STL images were integrated into one virtual skull using simulation software. Digitalized intermediate wafer was manufactured using CAD/CAM software and 3D printer, and used to move maxillary segment in real patient. Constructed virtual skull from 1 month postoperative CT scan was superimposedinto simulated virtual model to reveal accuracy. Almost maxillo-mandibular landmarks were placed in simulated position within 1 mm differences except right coronoid process. Thus 3D diagnosis, surgical simulation, and digitalized wafer could be useful method to orthognathic surgery in terms of accuracy.

Maxillary Reconstruction with Free Fibular Flap using 3D RP Model

Ahn, Kang-Min,Kim, Jong-Jin 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.1

Reconstruction of the maxilla is quite a difficult challenge for reconstructive surgeons. The maxilla is the most important part of the midface, which contributes to facial esthetics, mastication, swallowing, speech, supporting orbital contents and sinus function. Free fibular flap is most versatile to reconstruct jaw bone because of its adequate length, containing both soft and bony tissues and acceptance of dental implants. In this case report, a reconstruction of the maxilla using free fibular flap and dental implants is described in which rapid prototype was used before surgery to simulate the final prosthetic results.

Segmentation and 3D Visualization of Medical Image : An Overview

Kang, Jiwoo,Kim, Doyoung,Lee, Sanghoon 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.1

In this paper, an overview of segmentation and 3D visualization methods are presented. Commonly, the two kinds of methods are used to visualize organs and vessels into 3D from medical images such as CT(A) and MRI - Direct Volume Rendering (DVR) and Iso-surface Rendering (IR). DVR can be applied directly to a volume. It directly penetrates through the volume while it determines which voxels are visualizedbased on a transfer function. On the other hand, IR requires a series of processes such as segmentation, polygonization and visualization. To extract a region of interest (ROI) from the medical volume image via the segmentation, some regions of an object and a background are required, which are typically obtained from the user. To visualize the extracted regions, the boundary points of the regions should be polygonized. In other words, the boundary surface composed of polygons such as a triangle and a rectangle should be required to visualize the regions into 3D because illumination effects, which makes the object shaded and seen in 3D, cannot be applied directly to the points.

Application of 3D Simulation Surgery to Orbital Wall Fracture : A preliminary Case Study

Choi, Jong-Woo 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.1

The orbit has a very special anatomical structure. The complex anatomical structure should be restored when we encounter the patient with orbital wall fracture. Unless these specific anatomy were reconstructed well, the patient should suffer from various complications such enophthalmos, diplopia or orbital deformity. In addition, because the patient has a his own specific orbital shape, individualized approach will be necessary. The aim of this trial is to try to restore the original orbit anatomy as possible based on the mirrored three dimensional CT images based on the computer simulation. Preoperative computed tomography (CT) data were processed for the patient and a rapid prototyping (RP) model was produced. At the same time, the uninjured side was mirrored and superimposed onto the traumatized side, to create a mirror-image of the RP model. In order to restore the missing skipped images between the cuts of CT data because of the thinness of the orbital walls, we manipulated the DICOM data for imaging the original orbital contour using the preoperatively manufactured mirror-image of the RP model. And we fabricated Titanium-Medpor to reconstruct three-dimensional orbital structure intraoperatively. This prefabricated Titanium-Medpor was then inserted onto the defected orbital wall and fixed. Three dimensional approach based on the computer simulation turned out to be very successful in this patient. Individualized approach for each patient could be an ideal way to manage the traumatic patients in near future.

Measurement of Orbit using Standardized Processing of CT Scan

Kim, Yong Oock 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.1

Purpose Surgical correction of various occular problems which do not have visual problem in plastic surgical area is to normalize the appearance of the face by restoring the normal position of orbit and eyeball. With development of surgical technique, the orbit can be restored exactly in trauma patient and can be moved totally in hypertelorism, as an example of congenital disease. All these surgeries are based on the hypothesis that the position of oclular glove moves in the plane in a quantitatively predictable reationship to osseous orbit movement. However, no studies have critically evaluated between the change of periorbital soft tissue and the outcome of the surgical correction, because there is no method of objective, quantitave evaluation of the periorbital soft tissue. Method Author suggest the methodology for quantitative assessment of ocular and periocular fat changes using the manipulation of digital images of computed tomographic scan. Results The method was allowed to evaluate inter-dacryon distance, inter-centroid distance, movement of the medial orbital wall, movement of the lateral orbital wall, alteration of thickness of the lateral periorbital fat as indicator of movement of the orbital wall and orbit in the patient with congenital periorbital anomaly and postoperative periorbital surgery. The goal of surgical correction of various occular problems which do not have visual problem in plastic surgical area is to normalize the appearance of the face by restoring the normal position of orbit and eyeball. With development of surgical technique, the orbit can be restored exactly in trauma patient and can be moved totally in hypertelorism, as an example of congenital disease. All these sugeries are based on the hypothesis that the position of oclular glove moves in the plane in a quantitatively predictable relationship to osseous orbit movement. However, no studies have critically evaluated between the change of periorbital soft tissue and the outcome of the surgical correction, because there is no method of objective, quantitave evaluation of the periorbital soft tissue. In this report, author suggest the methodology for quantitative assessment of ocular and periocular fat changes using the manipulation of digital images of computed tomographic scan. Conclusion The method suggested is objective and accurate method in measurement of the orbital contents. It takes time and is not easy to do, however, this kind of measurement for fine structures will be more easily available in near future.

Application of 3D Simulation Surgery to Mandibular Asymmetry: Case Report

Lee, Sung-Hwa,Lee, Ho-Sung,Jung, Young-Soo,Park, Hyung-Sik,Jung, Hwi-Dong 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.2

Two-dimensional cephalometric analysis has been used for diagnosis and treatment of correction of mandibular asymmetry by many maxillofacial surgeons. And 2D analysis showed excellent results in many cases, however 2D has some drawbacks in diagnosis and treatment planning because of its fundamental limitation like overlapping. Today many physicians use 3D diagnosis & treatment tools to expect better results and reduce possible errors. The aim of this report is to present treatment procedures using 3D analysis and treatment modalities for mandibular asymmetry patients.

Mandibular Reconstruction with Free Fibular Flap and Dental Implant after Ablative Oral Cancer Surgery Using 3D RP Model: A Case Report

Kim, Duck-Hoon,Cha, Hyun-Suk,Ahn, Kang-Min 국제컴퓨터가상수술학회 2014 Journal of International Society for Simulation Su Vol.1 No.2

Reconstruction of the mandible after ablative oral cancer surgery requires esthetic and functional rehabilitation. Restoring facial symmetry and dentition need accurate preoperative surgical planning and meticulous surgical technique. Free fibular flap is most useful tools to reconstruct mandible because of its adequate length and height, simultaneous harvest of soft and hard tissues and placing dental implants. In this case report, recurred squamous cell carcinoma in the right mandible had been resected and free fibular flap was utilized for mandible reconstruction using 3D rapid prototype. Simulation surgery before dental implant placement has been performed for esthetic and functional prosthodontics.