• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.443-446
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• 2011

본 연구는 컴퓨터 단층촬영 영상 (CT, Computed Tomography Image)에서 치열궁 (Dental Arch)을 자동으로 검출하는 기법을 제안한다. 제안된 기법에서는 3차원 컴퓨터 단층촬영 영상을 입력 받고 영역 확장법을 이용하여 하악을 분할 한 후 하악의 단면에서 전체적인 치아의 영역을 분할을 한다. 치아의 영역에서 세선화 작업을 거친 후 곡선 정합법을 이용하여 최종 치열궁을 검출한다. 실험 데이터로 두개골 컴퓨터 단층 촬영 데이터를 사용하였다. 본 연구는 치과 영상 데이터로부터 파노라마 영상을 얻는데 이용 될 수 있고 치과 분야의 질병 진단 및 진찰에 이용될 것으로 기대된다.

• Progress in Medical Physics
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• v.9 no.1
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• pp.47-53
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• 1998

Nuclear Medicine Images have comparatively poor spatial resolution, making it difficult to relate the functional information which they contain to precise anatomical structures. Anatomical structures useful in the interpretation of SPECT /PET Images were radiolabelled. PET/SPECT Images Provide functional information, whereas MRI mainly demonstrate morphology and anatomical. Fusion or Image Registration improves the information obtained by correlating images from various modalities. Brain Scan were studied on one or more occations using MRI and SPECT. The data were aligned using a point pair methods and surface matching. SPECT and MR Images was tested using a three dimensional water fillable Hoffman Brain Phantom with small marker and PET and MR Image was tested using a patient data. Registration of SPECT and MR Images is feasible and allows more accurate anatomic assessment of sites of abnormal uptake in radiolabeled studies. Point based registration was accurate and easily implemented three dimensional registration of multimodality data set for fusion of clinical anatomic and functional imaging modalities. Accuracy of a surface matching algorithm and homologous feature pair matching for three dimensional image registration of Single Photon Emission Computed Tomography Emission Computed Tomography (SPECT), Positron Emission Tomography (PET) and Magnetic Resonance Images(MRD was tested using a three dimensional water fill able brain phantom and Patients data. Transformation parameter for translation and scaling were determined by homologous feature point pair to match each SPECT and PET scan with MR images.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.123-129
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• 2023

The purpose of this study was to analyze differences in imaging quality and dose difference between intra-venous (IV) and intra-arterial (IA) liver dynamic computed tomography (CT). Herein, retrospective, blinded analysis was conducted to analyze signal-to-noise and contrast-to-noise ratios in cases of patients who underwent IV or IA liver dynamic CT for transarterial chemoembolization (TACE), an interventional procedure for hepatocellular carcinoma. The dose length product (DLP) value stored in Picture Archive and Communication System (PACS) was used to calculate the effective dose and thereby compare differences in the dose between the two methods. The mean liver and spleen signal to noise ratio (SNR) was greater in IV-liver dynamic CT than in IA-liver dynamic CT; however, contrast to noise ratio (CNR) was higher in IA-liver dynamic CT than in IV-liver dynamic CT. However, there were no differences in DLP and effective dose between the two methods. In conclusion, our findings showed that IA-liver dynamic CT showed a similar effective dose and superior CNR compared with IV-liver dynamic CT. Further studies must analyze 3D angiography CT of the hepatic artery to clearly distinguish the feeding artery, which is the essential step in interventional procedures for hepatocellular carcinoma.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.2163-2170
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• 2009

We present an automated, energy minimized-based method for Lung parenchyma segmenting Chest Computed Tomography(CT) datasets. Deformable model is used for energy minimized segmentation. Quantitative knowledge including expected volume, shape of Chest CT provides more feature constrain to diagnosis or surgery operation planning. Segmentation subdivides an lung image into its consistent regions or objects. Depends on energy-minimizing, the level detail image of subdivision is carried. Segmentation should stop when the objects or region of interest in an application have been detected. The deformable model that has attracted the most attention to date is popularly known as snakes. Snakes or deformable contour models represent a special case of the general multidimensional deformable model theory. This is used extensively in computer vision and image processing applications, particularly to locate object boundaries, in the mean time a new type of external force for deformable models, called gradient vector flow(GVF) was introduced by Xu. Our proposed algorithm of deformable model is new external energy of GVF for exact segmentation. In this paper, Clinical material for experiments shows better results of proposal algorithm in Lung parenchyma segmentation on Chest CT.

• Progress in Medical Physics
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• v.27 no.2
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• pp.72-78
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• 2016

A CCD camera and an LED light source were combined to fabricate a compact optical CT scanner for the therapeutic radiation dose evaluation of a polymer gel dosimeter. After the collimated beam emitted by the LED passed through aquarium, gel phantom, and telecentric lens, an image was collected by the CCD camera and reconstructed using MATLAB. By using a stepping motor and LabVIEW, the gel dosimeter was rotated at every $0.72^{\circ}$, and the time for collecting 500 slice images per a revolution was within 20 min. At a spatial frequency of 4.5 lp/mm of the optical CT scanner, the modulation transfer function value was 72%. The linear correlation coefficient of the optical CT scanner for the polymer gel dosimeter was 0.987.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.23-24
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• 2009

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.376-381
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• 2014

In this study, we analyzed the computed tomography (CT) measurements of lung volume and density in dogs with relation to body weight, age, sex, and breed. The multi-detector CT examination of the thorax was performed on dogs without respiratory or cardiovascular diseases. Three-dimensional reconstruction of CT images facilitated measurement of lung volume and density. There was a statistical significant correlation between body weight and lung volume (p < 0.0001). Lung density significantly decreased with an increase in body weight (p = 0.0078). However, no correlation was seen between these lung parameters and either sex or age of the dogs. In conclusion, this study shows that body weight is an important factor to consider when interpreting total lung volume and density values measured by quantitative CT. We highlight the need for further study using quantitative CT in identifying the potential effects of sex, age, and disease status on these parameters.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.612-614
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• 1998

뇌정위 수술(Stereotactic Surgery)은 컴퓨터 단층영상과 자기공명 영상 같은 3차원 영상을 이용하여 뇌병변의 위치를 입체적으로 정확히 파악하여 정상 뇌에 대한 손상을 최소화하며 병변을 수술하는 기법이다. 본 논문에서는 수술 받을 환자의 컴퓨터 단층영상과 자기공명 영상 등 다양한 종류의 3차원 볼륨 데이터를 전처리한 다음 동일한 3차원 공간 내에서 정렬시켜 선택적 또는 동시적으로 3차원 영상을 가시화 하는 기법을 제안한다. 또한 3차원 영상에서 뇌정위 수술의 삽입점과 목표점을 지정할 수 있는 기능을 지원하며 수술 경로에 따른 가상 수술의 시뮬레이션을 통하여 수술 경로의 안전성을 검증할 수 있게 하였다.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.589-594
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• 2017

The objective of this study was to evaluate the enhancement effects of the quantum denoising system (QDS) on brain CT images. This retrospective study was conducted with 45 adults who visited G Radiology located in Gyungbuk for having brain CT tests between Jul 2017 and Oct 2017 after receiving consents. Subjects were divided into a control group (A group; no QDS(-) application during the brain CT test) and a treatment group (B Group; QDS(+) application during the brain CT test). The following conclusions were obtained from the study. The noise values at the Pons part and the Vermis part were significantly (p<0.05) lower in B Group ($Pons=5.41{\pm}1.05HU$; $Vermis=5.28{\pm}0.73HU$) than A Group ($Pons=6.92{\pm}0.98HU$; Vermis=6.72). The SNR values at the Pons part and the Vermis part were significantly (p<0.05) higher in B Group ($Pons=7.28{\pm}2.56$; $Vermis=8.63{\pm}3.04$) than A Group ($Pons=5.21{\pm}1.28$; $Vermis=6.23{\pm}1.49$). In conclusion, the results of this study suggested that the application of QDS to the brain CT test would enhance the signal to noise ratio (SNR) and the contrast to noise ratio (CNR) to provide an image more appropriate for diagnosis.

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.6
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• pp.22-30
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• 1979

A new circular ring position camera tomographic system termed "Oscillatory Dichotomic Ring" system is proposed and its performance is simulated. It is basically a circular ring system, composed of two half rings, which has the capability of scanning so that any sampling intervals can be obtained. Since finer sampling means poorer photon statistcs, simulations with varous signal dependent statistical noise effects, ray sampling and arrangement as well as related artifacts peculiar to the proposed Dichotomic Ring system are made.