• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.15.1-15.6
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• 2016

Background: The utilization of a cone-beam computed tomography (CT)-assisted surgical template allows for predictable results because implant placement plans can be performed in the actual surgery. In order to assess the accuracy of the CT-guided surgery, angular errors and shoulder/apex distance errors were evaluated by data fusion from before and after the placement. Methods: Computer-guided implant surgery was performed in five patients with 19 implants. In order to analyze differences of the implant fixture body between preoperative planned implant and postoperative placed implant, angular error and distance errors were evaluated. Results: The mean angular errors between the preoperative planned and postoperative placed implant was $3.84^{\circ}{\pm}1.49^{\circ}$; the mean distance errors between the planned and placed implants were $0.45{\pm}0.48mm$ horizontally and $0.63{\pm}0.51mm$ vertically at the implant neck and $0.70{\pm}0.63mm$ horizontally and $0.64{\pm}0.57mm$ vertically at the implant apex for all 19 implants. Conclusions: It is important to be able to utilize these methods in actual clinical settings by improving the various problems, including the considerations of patient mouth opening limitations, surgical guide preparation, and fixation.

• Journal of International Society for Simulation Surgery
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• v.2 no.2
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• pp.83-86
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• 2015

Recently, computer-assisted surgery is popular for performing well-planned operations. Computer-aided navigation system is helpful in maxillofacial surgery with real time instrument positioning and clear anatomic identification. Generally, segmental mandibulectomy and reconstruction flap surgery have done by extra-oral approach such as, submandibular approach. This case report describes performing intra-oral segmental mandibulectomy and reconstruction with monocortical deep circumflex iliac artery (DCIA) flap and CT guided implant surgery by using computer-aided surgical guide and navigation for managing ameloblastoma in a 31 years old female patient.

• Journal of Computing Science and Engineering
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• v.4 no.4
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• pp.368-387
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• 2010

We propose a novel method for the registration of 3D CT scans to 2D endoscopic images during the image-guided medialization laryngoplasty. This study aims to allow the surgeon to find the precise configuration of the implant and place it into the desired location by employing accurate registration methods of the 3D CT data to intra-operative patient and interactive visualization tools for the registered images. In this study, the proposed registration methods enable the surgeon to compare the outcome of the procedure to the pre-planned shape by matching the vocal folds in the CT rendered images to the endoscopic images. The 3D image fusion provides an interactive and intuitive guidance for surgeon by visualizing a combined and correlated relationship of the multiple imaging modalities. The 3D Magic Lens helps to effectively visualize laryngeal anatomical structures by applying different transparencies and transfer functions to the region of interest. The preliminary results of the study demonstrated that the proposed method can be readily extended for image-guided surgery of real patients.

• Journal of Korean Neurosurgical Society
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• v.29 no.1
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• pp.72-77
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• 2000

The authors describe the experience with the interactive image-guided Zeiss SMN system, which has been applied to 20 patients with various intracranial lesions during one year. Preoperative radiologic evaluation was CT scan in 6 cases, MRI in 14 cases. In all except one case, average fiducial registration errors were less than 2mm. There was no statistical difference in registration error between CT and MR image. This system considered to be relatively stable with respect to soft and hardware. Also it was useful for the designing of the scalp incision and bone flap and assessing the extent of resection in tumors, especially in gliomas. Moreover, it was helpful to evaluate complex surgical anatomy in skull base surgery.

• Journal of Korean Neurosurgical Society
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• v.63 no.2
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• pp.237-247
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• 2020

Objective : Fixation of the C1-2 segment is challenging because of the complex anatomy in the region and the need for a high degree of accuracy to avoid complications. Preoperative 3D-computed tomography (CT) scans can help reduce the risk of complications in the vertebral artery, spinal cord, and nerve roots. However, the patient may be susceptible to injury if the patient's anatomy does not match the preoperative CT scans. The intraoperative 3D image-based navigation systems have reduced complications in instrument-assisted techniques due to greater accuracy. This study aimed to compare the radiologic outcomes of C1-2 fusion surgery between intraoperative CT image-guided operation and fluoroscopy-guided operation. Methods : We retrospectively reviewed the radiologic images of 34 patients who underwent C1-2 fusion spine surgery from January 2009 to November 2018 at our hospital. We assessed 17 cases each of degenerative cervical disease and trauma in a study population of 18 males and 16 females. The mean age was 54.8 years. A total of 139 screws were used and the surgical procedures included 68 screws in the C1 lateral mass, 58 screws in C2 pedicle, nine screws in C2 lamina and C2 pars screws, four lateral mass screws in sub-axial level. Of the 34 patients, 19 patients underwent screw insertion using intraoperative mobile CT. Other patients underwent atlantoaxial fusion with a standard fluoroscopy-guided device. Results : A total of 139 screws were correctly positioned. We analyzed the positions of 135 screws except for the four screws that performed the lateral mass screws in C3 vertebra. Minor screw penetration was observed in seven cases (5.2%), and major pedicle screw penetration was observed in three cases (2.2%). In one case, the malposition of a C2 pedicle screw was confirmed, which was subsequently corrected. There were no complications regarding vertebral artery injury or onset of new neurologic deficits. The screw malposition rate was lower (5.3%) in patients who underwent intraoperative CT-based navigation than that for fluoroscopy-guided cases (10.2%). And we confirmed that the operation time can be significantly reduced by surgery using intraoperative O-arm device. Conclusion : Spinal navigation using intraoperative cone-beam CT scans is reliable for posterior fixation in unstable C1-2 pathologies and can be reduced the operative time.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.28 no.1
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• pp.4-17
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• 2019

Nowadays, Cone-Beam CT is widely supplied in dental clinics, the distribution rate in south korea is highly ranked worldwidely. Recently, The number of Cone-Beam CTs reached 10 thousands according to national healthcare system report. Also, dental manufacturers released many kinds of In-house 3D digital printers, the distribution rate of which rises rapidly in dental clinics. Accordingly, using Cone-Beam CT data and Intraloral scan data, the application of implant guide surgery is widespread in a unit of private clinic. Through the previous articles, the latest methods of computer-guided implant surgery are reviewed, and also the considerations for precise and reliable guide surgery are summarized.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.269-270
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• 1998

Image-guided surgery (IGS) system has become well known in the field of neurosurgery and spine surgery. A patient's anatomy is first registered to preoperatively acquired CT/ MRI data using the point matching algorithm. A magnetic field digitizer was used to measure the physical space data and the system was based on Workstation of Unix system. To evaluate the spatial accuracy of interactive IGS system, the phantom consisting of rods varied height and known location was used. The RMS error value between CT/MR images and real location was 3-4mm. For the more convenience of the surgery, we provide various image display modules.

• Journal of the Korean Orthopaedic Association
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• v.56 no.5
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• pp.398-403
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• 2021

Purpose: A biopsy is needed to diagnose soft tissue tumors. However, it is extremely difficult to pinpoint the site of a tumor due to the heterogeneity of sarcomas. Thus, even when an open biopsy is conducted, it is difficult to diagnose a soft tissue tumor. In such cases, an ultrasound (US)-guided biopsy is used to improve the diagnostic accuracy. This study evaluated the accuracy of US-guided biopsy for a diagnosis of soft tissue tumors found initially in a magnetic resonance (MR) perfusion and assessed the availability of positron emission tomography-computed tomography (PET-CT) for a diagnosis of soft tissue tumors. Materials and Methods: From January 2014 to December 2018, the US-guided biopsy was performed on 152 patients with a suspected soft tissue tumor found in an MR perfusion and 86 cases were definitively diagnosed with a soft tissue tumor. The accuracy of the US-guided biopsy was assessed retrospectively. Among the 86 cases, only MR perfusion was used before the biopsy in 50 cases, while both MR perfusion and PET-CT was conducted on 36 cases. The accuracy was analyzed to determine if the PET-CT could improve the precision of a biopsy. Results: From 86 cases, 34 out of 50 cases, in which only MR perfusion had been conducted, matched the result of the definitive diagnosis and the US-guided biopsy. 32 out of 36 cases, in which both PET-CT and MR perfusion were conducted, matched the definitive diagnosis and the US-guided biopsy. These results show significant differences in the accuracy of US-guided biopsy. In the case of soft tissue sarcomas, 6 out of 12 cases, in which only MR perfusion had been conducted, matched the result of the definitive diagnosis and the US-guided biopsy. 17 out of 18 cases, in which both PET-CT and MR perfusion were conducted, matched the definitive diagnosis. Moreover US-guided biopsy also showed significant differences in the accuracy of US-guided biopsy. Conclusion: In diagnosing soft tissue tumors, a US-guided biopsy is a well-known tool for its high accuracy. However, the heterogeneity of sarcoma makes it difficult to locate the exact site for a biopsy using only MR perfusion. Thus, the use of PET-CT will meaningfully improve the accuracy of a diagnosis by precisely targeting the site for the US-guided biopsy.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.196-207
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• 2018

An accurate implant placement with ideal location is significant for long-term success of the implant. An exact evaluation of nearby anatomic structures such as quality of residual bone, an inferior alveolar bone and a maxillary sinus is required. For a prosthetic-driven treatment, planned surgery, precise prosthesis and communication with the patient are significant requisites especially for full-mouth rehabilitation. In this case, the patient with severe alveolar bone resorption had a CT guided surgery supported by CT data and the data from scanning diagnostic wax-up. Afterward, edentulous area was restored by full mouth implant-supported prosthesis by using monolithic zirconia and CAD/CAM technique. This paper reports the outcome of the procedure which was remarkable both esthetically and functionally.

• Journal of Chest Surgery
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• v.42 no.5
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• pp.624-629
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• 2009

Background: Making the histologic diagnosis of small pulmonary nodules and ground glass opacity (GGO) lesions is difficult. CT-guided percutaneous needle biopsies often fail to provide enough specimen for making the diagnosis. Video-assisted thoracoscopic surgery (VATS) can be inefficient for treating non-palpable lesions. Preoperative localization of small intrapulmonary lesions provides a more obvious target to facilitate performing intraoperative. resection. We evaluated the efficacy of CT-guided localization with using a hook wire and this was followed by VATS for making the histologic diagnosis of small intrapulmonary nodules and GGO lesions. Material and Method: Eighteen patients (13 males) were included in this study from August 2005 to March 2008. 18 intrapulmonary lesions underwent preoperative localization by using a CT-guided a hook wire system prior to performing VATS resection for intrapulmonary lesions and GGO lesions. The clinical data such as the accuracy of localization, the rate of conversion-to-thoracotomy, the operation time, the postoperative complications and the histology of the pulmonary lesion were retrospectively collected. Result: Eighteen VATS resections were performed in 18 patients. Preoperative CT-guided localization with a hook-wire was successful in all the patients. Dislodgement of a hook wire was observed in one case. There was no conversion to thoracotomy, The median diameter of lesions was 8 mm (range: $3{\sim}15\;mm$). The median depth of the lesions from the pleural surfaces was 5.5 mm (range: $1{\sim}30\;mm$). The median interval between preoperative CT-guided with a hook-wire and VATS was 34.5 min (range: ($10{\sim}226$ min). The median operative time was 43.5.min (range: $26{\sim}83$ min). In two patients, clinically insignificant pneumothorax developed after CT-guided localization with a hook-wire and there were no other complications. Histological examinations confirmed 8 primary lung cancers, 3 cases of metastases, 3 cases of inflammation, 2 intrapulmonary lymph nodes and 2 other benign lesions. Conclusion: CT-guided localization with a hook-wire followed by VATS for treating small intrapulmonary nodules and GGO lesions provided a low conversion thoracotomy rate, a short operation time and few localization-related or postoperative complications. This procedure was efficient to confirm intrapulmonary lesions and GGO lesions.