• Journal of Korean Neurosurgical Society
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• v.47 no.6
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• pp.415-419
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• 2010

Objective : It is usually difficult to perform the neuroendoscopic procedure in patients without hydrocephalus due to difficulties with ventricular cannulation. The purpose of this study was to find out the value of navigation guided neuroendoscopic biopsy in patients with peri- or intraventricular tumors without hydrocephalus. Methods : Six patients with brain tumors without hydrocephalus underwent navigation-guided neuroendoscopic biopsy. The procedure was indicated for verification of the histological diagnosis of the neoplasm, which was planned to be treated by chemotherapy and/or radiotherapy as the first line treatment, or establishment of the pathological diagnosis for further choice of the most appropriate treatment strategy. Results : Under the guidance of navigation, targeted lesion was successfully approached in all patients. Navigational tracking was especially helpful in entering small ventricles and in approaching the third ventricle through narrow foramen Monro. The histopathologic diagnosis was established in all of 6 patients : 2 germinomas, 2 astrocytomas, 1 dysembryoplastic neuroepithelial tumor and 1 pineocytoma. The tumor biopsy sites were pineal gland (n = 2), suprasellar area (n = 2), subcallosal area (n = 1) and thalamus (n = 1). There were no operative complications related to the endoscopic procedure. Conclusion : Endoscopic biopsy or resection of peri- or intraventricular tumors in patients without hydrocephalus is feasible. Image-guided neuroendoscopic procedure improved the accuracy of the endoscopic approach and minimized brain trauma. The absence of ventriculomegaly in patients with brain tumor may not be served as a contraindication to endoscopic tumor biopsy.

• Proceedings of the KIEE Conference
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• 1999.11c
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• pp.836-838
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• 1999

This paper describes stereo image compression algorithm using disparity and JPEG. because similar images are images with common features, similiar pixel distributions, and similar edge distributions. Fields such as medical imaging or satellite imaging often need to store large collections of similar images. that is, a conventional stereo system with a single left-right pair needs twice data as a monoscopic imaging system. as a result we need compression method compatible stereo image, in this paper after we use JPEG in basic compression method and stereo matching using adaptiv window, we get disparity information, we restored right image using by restored left image and disparity.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.545-550
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• 2004

An Image processing algorithm was developed and tested to detect abnormal parts, such as esophagitis, with the information on the color and the texture in a digital clinic endoscopic image by using discriminal analysis. In order to develope the algorithm, the critical parameters from many parameters were found to distinguish between normal and abnormal part in the various images. The Inflammation and ulceration which are very important diagnostic indexes were detected by the algorithm. The algorithm proved to a reliable program for detecting abnormal parts with 20 images. A success rate was 92.8% and 92.4% in the calibration stage and the validation stage by using the algorithm with discriminal analysis.

• Korean Journal of Optics and Photonics
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• v.30 no.6
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• pp.243-248
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• 2019

The respiratory tract is an essential part of the respiratory system involved in the process of respiration. However, if stenosis occurs, it interferes with breathing and can even lead to death. Asthma is a typical example of a reversible cause of airway narrowing, and the number of patients suffering from acute exacerbation is steadily increasing. Therefore, it is important to detect airway narrowing early and prevent the patient's condition from worsening. Optical coherence tomography (OCT), which has high resolution, is suitable for observing the microstructure of tissues. In this study we developed an endoscopic OCT system. We combined a 1300-nm OCT system with a servo motor, which can rotate at a high speed. A catheter was pulled back using a linear stage while imaging with 360° rotation by the motor. The motor was selected considering various requirements, such as torque, rotational speed, and gear ratio of pulleys. An ex vivo rabbit tracheal model was used as a sample, and the sample and catheter were immobilized by acrylic structures. The OCT images provided information about the structures of the mucosa and submucosa. The difference between normal and stenosed parts in the trachea was confirmed by OCT. Furthermore, through a three-dimensional (3-D) reconstruction process, it was possible to identify and diagnose the stenosis in the 3-D image of the airway, as well as the cross-sectional image. This study would be useful not only for diagnosing airway stenosis, but also for realizing 3-D imaging.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.414-421
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• 2019

Objective : To evaluate 3-dimensional magnetic resonance imaging (MRI) of Kambin's safe zone to calculate maximum cannula diameter permissible for safe percutaneous endoscopic lumbar discectomy. Methods : Fifty 3D MRIs of 19 males and 31 females (mean, 47 years) were analysed. Oblique, axial and sagittal views were used for image analysis. Three authors calculated the inscribed circle (cannula diameter) individually, within the neural (original) and bony Kambin's triangle in oblique views, disc heights on sagittal views and root to facet distances at upper and lower end plate levels on axial views and their averages were taken. Results : The mean root to facet distances at upper end plate level measured on axial sections increased from $3.42{\pm}3.01mm$ at L12 level to $4.57{\pm}2.49mm$ at L5S1 level. The mean root to facet distances at lower end plate level measured on axial sections also increased from $6.07{\pm}1.13mm$ at L12 level to $12.9{\pm}2.83mm$ at L5S1 level. Mean maximum cannula diameter permissible through the neural Kambin's triangle increased from $5.67{\pm}1.38mm$ at L12 level to $9.7{\pm}3.82mm$ at L5S1 level. The mean maximum cannula diameter permissible through the bony Kambin's triangle also increased from $4.03{\pm}1.08mm$ at L12 level to $6.11{\pm}1mm$ at L5S1 level. Only 2% of the 427 bony Kambin's triangles could accommodate a cannula diameter of 8mm. The base of the bony Kambin's triangle taken in oblique view (3D MRI) was significantly higher than the root to facet distance at lower end plate level taken in axial view. Conclusion : The largest mean diameter of endoscopic cannula passable through "bony" Kambin's triangle was distinctively smaller than the largest mean diameter of endoscopic cannula passable through "neural" Kambin's triangle at all levels. Although proximity of exiting root to the facet joint is always taken into consideration before PELD procedure, our 3D MRI based anatomical study is the first to provide actual maximum cannula dimensions permissible in this region.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.181.5-181
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• 2001

This paper presents the method of 3D reconstruction of the depth information from the endoscopic stereo scopic images. After camera modeling to find camera parameters, we performed feature-point based stereo matching to find depth information. Acquired some depth information is finally 3D reconstructed using the NURBS(Non Uniform Rational B-Spline) algorithm. The final result image is helpful for the understanding of depth information visually.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.541-541
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• 2000

This paper Presents the method of 3D reconstruction of the depth information from the endoscopic stereo scopic images. After camera modeling to find camera parameters, we peformed feature-point based stereo matching to find depth information. Acquired some depth information is finally 3D reconstructed using the NURBS(Non Uniform Rational B-Spline) algorithm. The final result image is helpful for the understanding of depth information visually.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1019-1023
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• 2000

Objective : Endoscopic third ventriculostomy is gaining popularity as a minimally invasive surgical option for certain types of hydrocephalus as an alternative to shunting. The authors have tried to fenestrate down to the subdural space passing through the prepontine cistern to lessen or avoid the chance of redoing due to healing. Materials and Method : A 48-year-old male patient with several years of intractable headache was presented. Magnetic Resonance Image(MRI) of the brain revealed marked ventricular dilatation with stenotic cerebral aqueduct. A 2.3mm flexible steerable endoscope($Neuroview^{(R)}$) was introduced via precoronal route and accessed to the third ventricular floor. Using 3-French Fogarty balloon catheter, thin third ventricular floor and the arachnoid membrane of the prepontine cistern were fenestrated, so called "double fenestration". To confirm the fenestration, subdural compa-rtment of the left abducens nerve was identified during the procedure. Forceful pulsating flow through the orifice convinced the patency of the opening. Results : The patient was discharged on the third postoperative day without any postoperative complications. The postoperative follow-up MRI of the brain, at second and sixth months, clearly demonstrated the flow void through the third ventricular floor. Conclusions : Endoscopic third ventriculostomy was successfully performed on an adult hydrocephalus patient with aqueduct stenosis. The third ventricular floor and arachnoid membrane of the prepontine cistern were fenestrated to achieve double fenestration to minimize the chance for failure. The details of this procedure and results are described.

• Journal of Digestive Cancer Research
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• v.5 no.2
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• pp.120-124
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• 2017

A-49-year-old male patient with no specific medical history was admitted to the clinic because of persistent epigastric pain radiating to back for 4 months. He had multiple parenchymal tumors in body and tail of pancreas, para-spinal muscle, and mediastinum on abdomen CT image. Cytologic examination of the pancreas which was done by endoscopic ultrasound guided fine needle aspiration (EUS-FNA) showed adenocarcinoma, whereas histological examination of the para-spinal mass showed undifferentiated sarcoma. Histologic examination of the pancreatic mass was made through endoscopic ultrasound guided fine needle biopsy (EUS-FNB) for accurate diagnosis, and the histologic examination of both the pancreas and posterior mediastinal mass showed the same undifferentiated sarcoma. Therefore, we reviewed the cytopathic tissue obtained from the pancreas for the first time, and it was confirmed to be similar to histologic findings in the mediastinal mass.

• Journal of Digestive Cancer Research
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• v.8 no.1
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• pp.1-50
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• 2020

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.