• Title/Summary/Keyword: 3-D reconstruction

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An Analysis of Vertical Position Accuracy for the Three-Dimensional Spatial Data Object Utilizing the Public Information (공공데이터를 활용한 3차원 공간정보 객체의 수직위치 정확도 분석)

  • Kim, Jeong Taek;Yi, Su Hyun;Kim, Jong Il;Bae, Sang Won
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.3
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    • pp.137-143
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    • 2014
  • Recently, as new paradigm for government operation called government 3.0, government is actively operating policy opening and sharing public data. In addition, the Ministry of Land are operating an open platform integrated map service (the VWorld) which provides a variety of video contents such as the country's national spatial information, traffic information and three-dimensional building for the public. According to W3C Foundation's Open Data Status Report(2013), our country has the evaluated results that the part of the government's policy support and planning is good while the part of the data management is vulnerable. So our country needs the quality improvement for the data management. In addition, a digital aerial photograph image data is required to be up-to-date for the three-dimensional spatial object data. In this paper, we present the method for enhancement of the accuracy of vertical position and for maintainment of up-to-date vertical position. Our methods evaluate the data quality and analyze the cause of error of measurement utilizing the national standard quality assessment method. The result of research shows that the accuracy of vertical position is improved if the height of the building captain is adjusted by the quality assessment values and a three-dimensional model has up-to-date data if reconstruction and extension information of construction register is utilized.

Evaluation for Optimization of CT Dose Reduction Methods in PET/CT (PET/CT 검사 시 CT 피폭선량 감소 방법들의 최적화 평가)

  • Do, Yong Ho;Lee, Hong Jae;Kim, Jin Eui
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.2
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    • pp.55-62
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    • 2015
  • Purpose Various methods for reducing radiation exposure have been continuously being developed. The aim of this study is to evaluate effectiveness of dose reduction, image quality and PET SUV changes by applying combination of automatic exposure dose(AEC), automated dose-optimized selection of X-ray tube voltage(CAREkV) and sinogram affirmed iterative reconstruction(SAFIRE) which can be controled by user. Materials and Methods Torso, AAPM CT performance and IEC body phantom images were acquired using biograph mCT64, (Siemens, Germany) PET/CT scanner. Standard CT condition was 120 kV, 40 mAs. Radiation exposure and noise were evaluated by applying AEC, CAREkV(120 kV, 40 mAs) and SAFIRE(120 kV, 25 mAs) with torso phantom compare to standard CT condition. And torso, AAPM and IEC phantom images were acquired with combination of 3 methods in condition of 120 kV, 25 mAs to evaluate radiation exposure, noise, spatial resolution and SUV changes. Results When applying AEC, CTDIvol and DLP were decreased by 50.52% and 50.62% compare to images which is not applying AEC. mAs was increased by 61.5% to compensate image quality according to decreasing 20 kV when applying CAREkV. However, CTDIvol and DLP were decreased by 6.2% and 5.5%. When reference mAs was the lower and strength was the higher, reduction of radiation exposure rate was the bigger. Mean SD and DLP were decreased by 2.2% and 38% when applying SAFIRE even though mAs was decreased by 37.5%(from 40 mAs to 25 mAs). Combination of 3 methods test, SD decreased by 5.17% and there was no significant differences in spatial resolution. And mean SD and DLP were decreased by 6.7% and 36.9% compare to 120 kV, 40 mAs with AEC. For SUV test, there was no statistical differences(P>0.05). Conclusion Combination of 3 methods shows dose reduction effect without degrading image quality and SUV changes. To reduce radiation exposure in PET/CT study, continuous effort is needed by optimizing various dose reduction methods.

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A Study on the Optimum Amount of Contrast Media in Brain Angiography (뇌 혈관검사 시 적정 조영제량에 관한 연구)

  • Kim, Gyoo-Hyung;Lee, Sang-Ho
    • Journal of radiological science and technology
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    • v.41 no.2
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    • pp.123-128
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    • 2018
  • Recently, the use of contrast agents has been increasing as a broader range of tests and dynamic tests have become common due to the development of equipment and imaging techniques such as Multi-Detector CT. However, the side effects of using contrast agents have been reduced by the development of non-ionic contrast agents, but they are still occurring often. The purpose of this study was to propose a method to minimize the side effect of contrast agent by using the amount of contrast agent injected to the brain angiography test to suppress excessive use of contrast agent and analyze the amount of contrast agent. Patients who were prescribed Brain Angiography due to cerebrovascular disease, According to the results of the comparison of the results obtained by dividing into 4 groups of 10ml each according to the amount of contrast medium injected with contrast agent according to the BMI of the patient, BA and SNR were not different between groups, and even if the amount of contrast injection was reduced, there was no problem in the evaluation of CT angiography through 3D reconstruction. This result shows that even if the contrast medium is injected into the blood vessels of the patient first and then the contrast medium is used as the physiological saline solution, the contrast medium is reduced by 40% it can be expected to minimize.

Recent Advances in Nuclear Medicine Imaging Instrumentation (핵의학 영상기기의 최근 진보)

  • Jung, Jin-Ho;Choi, Yong;Hong, Key-Jo;Min, Byung-Jun;Hu, Wei;Kang, Ji-Hoon
    • Nuclear Medicine and Molecular Imaging
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    • v.42 no.2
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    • pp.98-111
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    • 2008
  • This review introduces advances in clinical and pre-clinical single photon emission computed tomography (SPECT) and positron emission tomography (PET) providing noninvasive functional images of biological processes. Development of new collimation techniques such as multi-pinhole and slit-slat collimators permits the improvement of system spatial resolution and sensitivity of SPECT. Application specific SPECT systems using smaller and compact solid-state detector have been customized for myocardial perfusion imaging with higher performance. Combined SPECT/CT providing improved diagnostic and functional capabilities has been introduced. Advances in PET and CT instrumentation have been incorporated in the PET/CT design that provide the metabolic information from PET superimposed on the anatomic information from CT. Improvements in the sensitivity of PET have achieved by the fully 3D acquisition with no septa and the extension of axial field-of-view. With the development of faster scintillation crystals and electronics, time-of-flight (TOF) PET is now commercially available allowing the increase in the signal-to-noise ratio by incorporation of TOF information into the PET reconstruction process. Hybrid PET/SPECT/CT systems has become commercially available for molecular imaging in small animal models. The pre-clinical systems have improved spatial resolution using depth-of-interaction measurement and new collimators. The recent works on solid state detector and dual modality nuclear medicine instrumentations incorporating MRI and optical imagers will also be discussed.

Evaluation of orthodontics for treating temporo-mandibular joint disorders using a stereo camera (스테레오 카메라를 이용한 측두하악관절 교정장치(NO SICK)의 성능 평가)

  • Yun, Hong-Ii;Park, Joon-Su;Chung, Koo-Yeong;Shin, Ki-Young;Park, Joon-Ki
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.8 no.5
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    • pp.359-366
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    • 2015
  • TMJ(TemporoMandibular Joint) is considered as the most important articulation in human body for maintaining the balance. Thus it is one of the main treatment areas in Chiropractic. Instead of Chiropractic treatment, NOSICK, a TMJ balancing device, can be used. As there is no such device to quantify the effect of NOSICK, a system was developed to measure the effect of NOSICK. This system is composed of stereo vision, infrared lights, and infrared through filter, etc. It requires optical markers for the measurement. 8 land markers were selected from the face which will show different displacement as NOSICK is applied. 11 test subjects were measured with the system developed with and without NOSICK applied. Quantifiable displacement of markers before and after applying NOSICK was successfully measured with the system developed.

Molecular Characterization of Echovirus 30-Associated Outbreak of Aseptic Meningitis in Korea in 2008

  • Choi, Young-Jin;Park, Kwi-Sung;Baek, Kyoung-Ah;Jung, Eun-Hye;Nam, Hae-Seon;Kim, Yong-Bae;Park, Joon-Soo
    • Journal of Microbiology and Biotechnology
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    • v.20 no.3
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    • pp.643-649
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    • 2010
  • Evaluation of the primary etiologic agents that cause aseptic meningitis outbreaks may provide valuable information regarding the prevention and management of aseptic meningitis. In Korea, an outbreak of aseptic meningitis caused by echovirus type 30 (E30) occurred from May to October in 2008. In order to determine the etiologic agent, CSF and/or stool specimens from 140 children hospitalized for aseptic meningitis at Soonchunhyang University Cheonan Hospital between June and October of 2008 were tested for virus isolation and identification. E30 accounted for 61.7% (37 cases) and echovirus 6 accounted for 21.7% (13 cases) of all the human enteroviruses (HEVs) isolates (60 cases in total). For the molecular characterization of the isolates, the VP1 gene sequence of 18 Korean E30 isolates was compared pairwise using the MegAlign with 34 reference strains from the GenBank database. The pairwise comparison of the nucleotide sequences of the VP1 genes demonstrated that the sequences of the Korean strains differed from those of lineage groups A, B, C, D, E, F, and G. Reconstruction of the phylogenetic tree based on the complete VP1 nucleotide sequences resulted in a monophyletic tree, with eight clustered lineage groups. All Korean isolates were segregated from other lineage groups, thus suggesting that the Korean strains were a distinct lineage of E30, and a probable cause of this outbreak. This manuscript is the first report, to the best of our knowledge, of the molecular characteristics of E30 strains associated with an aseptic meningitis outbreak in Korea, and their respective phylogenetic relationships.

Surgical stent for dental implant using cone beam CT images (콘빔형 전산화단층영상을 이용한 치과임플란트 식립유도장치 개발)

  • Choi, Hyung-Soo;Kim, Gyu-Tae;Choi, Yong-Suk;Hwang, Eui-Hwan
    • Imaging Science in Dentistry
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    • v.40 no.4
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    • pp.171-178
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    • 2010
  • Purpose : The purpose of this study is to develop a surgical stent for dental implant procedure that can be easily applied and affordable by using cone beam computerized tomography (CBCT). Materials and Methods : Aluminum, Teflon-PFA (perfluoroalkoxy), and acetal (polyoxymethylene plastic) were selected as materials for the surgical stent. Among these three materials, the appropriate material was chosen using the CBCT images. The surgical stent, which could be easily placed into an oral cavity, was designed with chosen material. CBCT images of the new surgical stent on mandible were obtained using Alphard-3030 dental CT system (Asahi Roentgen Co., Ltd., Kyoto, Japan). The point of insertion was prescribed on the surgical stent with the multiplanar reconstruction software of OnDemand3D (CyberMed Inc., Seoul, Korea). Guide holes were made at the point of insertion on the surgical stent using newly designed guide jig. CBCT scans was taken for the second time to verify the accuracy of the newly designed surgical stent. Results : Teflon-PFA showed radiologically excellent image characteristics for the surgical stent. High accuracy and reproducibility of implantation were confirmed with the surgical stent. Conclusion : The newly designed surgical stent can lead to the accurate implantation and achieve the clinically predictable result.

Motor Imagery based Brain-Computer Interface for Cerebellar Ataxia (소뇌 운동실조 이상 환자를 위한 운동상상 기반의 뇌-컴퓨터 인터페이스)

  • Choi, Young-Seok;Shin, Hyun-Chool;Ying, Sarah H.;Newman, Geoffrey I.;Thakor, Nitish
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.6
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    • pp.609-614
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    • 2014
  • Cerebellar ataxia is a steadily progressive neurodegenerative disease associated with loss of motor control, leaving patients unable to walk, talk, or perform activities of daily living. Direct motor instruction in cerebella ataxia patients has limited effectiveness, presumably because an inappropriate closed-loop cerebellar response to the inevitable observed error confounds motor learning mechanisms. Recent studies have validated the age-old technique of employing motor imagery training (mental rehearsal of a movement) to boost motor performance in athletes, much as a champion downhill skier visualizes the course prior to embarking on a run. Could the use of EEG based BCI provide advanced biofeedback to improve motor imagery and provide a "backdoor" to improving motor performance in ataxia patients? In order to determine the feasibility of using EEG-based BCI control in this population, we compare the ability to modulate mu-band power (8-12 Hz) by performing a cued motor imagery task in an ataxia patient and healthy control.

Free Tissue Transfer in Sickle Cell Disease: A Case Report and Systematic Review

  • Anne Huang;Ronak A. Patel;Lawrence J. Gottlieb
    • Archives of Plastic Surgery
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    • v.50 no.3
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    • pp.315-324
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    • 2023
  • Hemoglobinopathies such as sickle cell disease (SCD) are traditionally considered a relative contraindication to free tissue transfer, due to concerns that erythrocyte sickling will increase the risk of microvascular thrombosis and flap failure. This article describes a case report with the successful use of free tissue transfer in a patient with SCD and provides a systematic literature review on free tissue transfer in SCD. A retrospective chart review was performed of a patient with SCD who underwent free tissue transfer at the authors' institution. A systematic literature review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed using the keywords "free tissue transfer," "free flap," or "microsurgery" and "sickle cell" on PubMed, Ovid/Medline, and Scopus. A 29-year-old male with delayed presentation of an electrical burn to the face and scalp underwent wound closure with a free anterolateral thigh flap. Key management principles included red blood cell transfusion to keep hemoglobin S under 30% and hemoglobin greater than 10 g/dL, maintenance of hydration, normothermia, adequate analgesia, and postoperative anticoagulation. Systematic literature review identified 7 articles describing 13 cases of free tissue transfer in 10 patients with SCD, with combined complete free flap success in 10 of the 13 flaps. Free tissue transfer can be successfully performed in patients with SCD. However, evidence on the optimal management of this unique patient population in the perioperative period after free tissue transfer is limited to case reports in the literature.

Cone-beam computed tomographic evaluation of the root canal anatomy of the lower premolars and molars in a Brazilian sub-population

  • Jessica Cecilia Almeida;Amanda Pelegrin Candemil;Gunther Ricardo Bertolini;Aline Evangelista Souza-Gabriel;Antonio Miranda Cruz-Filho;Manoel Damiao Sousa-Neto;Ricardo Gariba Silva
    • Imaging Science in Dentistry
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    • v.53 no.1
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    • pp.77-82
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    • 2023
  • Purpose: This study evaluated anatomical variations in the root canals of the lower premolars and molars in a Brazilian sub-population using cone-beam computed tomography (CBCT). Materials and Methods: In total, 121 CBCT images of patients were selected from a database. All images contained lower first and second premolars and molars on both sides of the arch, fully developed roots, and no treatment, resorption, or calcifications. In each image, the root canals of the lower premolars and molars were evaluated according to the Vertucci classification in On-Demand 3D software in the multiplanar reconstruction with dynamic navigation. Twenty-five percent of the images were re-assessed to analyze intraobserver confidence with the kappa test. Data were statistically evaluated with linear regression to evaluate the correlations of anatomic variations with age and sex, and the Wilcoxon test to analyze the laterality of variations, with a significance level of 5%. Results: The intraobserver agreement (0.94) was excellent. In general, the root canals of lower premolars and molars showed a higher prevalence of type I than other Vertucci classification types, followed by type V in premolars and type II in molars. When the molar roots were evaluated separately, type II was more frequent in mesial roots and type I in distal roots. Although age showed no correlations with the results, sex and laterality showed correlations with tooth 45 and the lower second premolars, respectively. Conclusion: The lower premolars and molars of a Brazilian sub-population showed a wide range of root canal anatomic variations.