• Archives of Plastic Surgery
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• v.35 no.2
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• pp.201-204
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• 2008

Purpose: Now the CT scanner and PACS program proved to be an excellent instrument for detection and localization of most facial foreign bodies above certain minimum levels of detectability. The severity of injury in penetrating trauma on the face is often underestimated in physical examination. Wood, with its porous consistency and organic nature, provides a good medium for microbial agents. This is a report of our recent experience with wooden foreign bodies in the parotid gland imaged with CT. Methods: A 9-year-old boy was referred for evaluation of possible retained foreign body within his face. One day earlier, he had fallen, face down approximately 1 miter onto ground. He had subsequently undergone an exploration of his right parotido-masseteric area at an outside hospital with repair of a right facial laceration. Enhanced 2 mm axial and coronal CT scans were obtained through the face. Axial and coronal CT images were obtained with a General Electric(Milwaukee, Wis) 9800 CT scanner at 130 kV, 90 mA, with a 2 mm section thickness. Results: We finally decided the linear "gas" attenuation was a foreign body because of its linear configuration, which did not conform to that of an anatomic structure, and on the basis of articles that described a wood foreign body in the orbit as having the appearance of air. We found that wood was hypoattenuating($-464{\pm}27HU$). Conclusion: We recommend this type of software program for CT scanning for any patient with an injury on the face in which a foreign body is suspected.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.1
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• pp.1-5
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• 2009

The Platelet Function Analyzer (PFA)$^{(R)}$-100 measures the ability of platelets activated in a high-shear environment to occlude an aperture in a membrane treated with collagen and epinephrine (CEPI) or collagen and ADP (CADP). The time taken for the flow across the membrane to stop (closure time, CT) is recorded. The aim of this study was to assess the potential of the PFA$^{(R)}$-100 as a primary clinical screening tool using the wide spectrum of clinical samples assessed for platelet function as well as to perform the optimal algorithm for the use of PFA$^{(R)}$-100. We established the reference interval in 460 hospital inpatients defined as having normal platelet function based on classical laboratory tests. The reference interval by using the range $5^{th}$ and $95^{th}$ percentile was 84~251 seconds for males CEPI-CT and 85~249 seconds for females CEPI-CT. A total of 1,200 inpatients were enrolled to identify impaired hemostasis before surgical interventions. The abnormal group showing prolonged CEPI-CT was 303 cases (18.9%). Only 3 cases had both abnormal CEPI-CT and CADP-CT. Several factors including sample errors, drugs, hematologic abnoralities were contributed to unexpected prolonged CEPI-CT for screening test. The von Willebrand factor (vWF:Ag) assay was performed only in one patient to verify the algorithm for the use of PFA$^{(R)}$-100. The PFA$^{(R)}$-100 was sensitive and rapid method for primary screening test of platelet dysfunction, so we can substitute it for the bleeding time in routine clinical practice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4418-4424
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• 2011

This study is aimed to assess the effect of the gamma ray of 511keV energy which is emitted from phantom where the positron emission radionuclide was injected on X-ray CT image. As a scanning method, the CT number and pixel value of the reference image where water was injected(0 mCi), and those acquired by changing the capacity of 18F(Fluorine), positron emission radionuclide, into 1 mCi, 2 mCi, 5 mCi, and 10 mCi were measured. As a result of measuring the CT number(HU) of the phantom image where the positron emission radionuclide($^{18}F$) was injected, there were reference water ($-7.58{\pm}0.66$ HU), 1 mCi($-9.85{\pm}0.50$ HU), 2 mCi($-10.27{\pm}0.21$ HU), 5 mCi($-11.31{\pm}0.66$ HU), and 10 mCi($-13.47{\pm}0.38$ HU). Compared with the image where it was filled with water, there was a reduction of 5.89 Hu in 10 mCi, 3.73 in 5 mCi, 2.69 HU in 2 mCi, and 2 HU in 1 mCi. As for the pixel value of the phantom image, there were reference water ($-2.70{\pm}0.75$), 1 mCi($-4.72{\pm}0.58$), 2 mCi($-6.01{\pm}0.78$), 5 mCi($-6.10{\pm}0.84$), and 10 mCi($-8.20{\pm}0.60$). Compared with the reference image, there was a reduction of 5.50 in 10 mCi, 3.40 in 5 mCi, 3.10 in 2 mCi, and 2.02 in 1 mCi. Through this experiment, it was indicated that, with the increase in the dose of the positron emission radionuclide($^{18}F$), the CT number and the pixel value of the image reduced proportionally, and the width of reduction showed a similar value, too. Accordingly, according to the degree of change in X-ray CT image due to the positron emission radionuclide in the quality control item of PET/CT, the proper standard should be established and it should be periodically managed.

• Proceedings of the KIEE Conference
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• summer
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• pp.524-526
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• 2004

We perform intelligent substation construction of 154kV class with KEPRI. The intelligent substation is build in Gochang 765kV testing facility and consists of electronic instruments, digital control panel, remote monitoring and diagnosis system, and digital relay system. Rogowski coil type CT(RCT) and capacitive voltage divider(CVD) are applicable for instrument transformer of conventional type. Digital control panel(UP) replaces local panel which is drived by mechanical operation. For monitoring condition of GIS and TR, various sensors are used. In this paper, we report the synopsis and the progress state of project.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.101-102
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• 2006

345kV 변전소는 국내 전력계통의 근간으로서 고장 시계통 안정도에 미치는 영향이 크기 때문에 고장 제거가 착신하고 신속해야 한다. 따라서 345kV 변전소의 보호 장치들은 CT, PT, 차단기(trip coil), 보호계전기, DC전원 등이 모두 2계열화되어 있으며 보호 계전기는 각 계열마다 주보호와 후비보호가 따로 구비되어 있다. 본 논문에서는 34skv 변압기 보호용 보호계전기에 내장된 계전요소들의 유기적인 성능 검증을 할 수 있는 동특성 시험에 관한 기반 구축 과정 및 결과에 대해서 기술한다.

• Journal of Korean Neurosurgical Society
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• v.50 no.1
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• pp.6-10
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• 2011

Objective : Spontaneous acute subdural hematomas (aSDH) secondary to ruptured intracranial aneurysms are rarely reported. This report reviews the clinical features, diagnostic modalities, treatments, and outcomes of this unusual and often fatal condition. Methods : We performed a database search for all cases of intracranial aneurysms treated at our hospital between 2005 and 2010. Patients with ruptured intracranial aneurysms who presented with aSDH on initial computed tomography (CT) were selected for inclusion. The clinical conditions, radiologic findings, treatments, and outcomes were assessed. Results : A total of 551 patients were treated for ruptured intracranial aneurysms during the review period. We selected 23 patients (4.2%) who presented with spontaneous aSDH on initial CT. Ruptured aneurysms were detected on initial 3D-CT angiography in all cases. All ruptured aneurysms were located in the anterior portion of the circle of Willis. The World Federation of Neurosurgical Societies grade on admission was V in 17 cases (73.9%). Immediate decompressive craniotomy was performed 22 cases (95.7%). Obliteration of the ruptured aneurysm was achieved in all cases. The Glasgow outcome scales for the cases were good recovery in 5 cases (21.7%), moderate disability to vegetative in 7 cases (30.4%), and death in 11 cases (47.8%). Conclusion : Spontaneous aSDH caused by a ruptured intracranial aneurysm is rare pattern of aneurysmal subarachnoid hemorrhage. For early detection of aneurysm, 3D-CT angiography is useful. Early decompression with obliteration of the aneurysm is recommended. Outcomes were correlated with the clinical grade and CT findings on admission.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.379-381
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• 2002

A single CdZnTe detector is tested for suitability in a prototype CT/ SPECT system designed to acquire both emission and transmission data. The detector has the size of 1${\times}$l-cm$^2$ with 4${\times}$4 1.5${\times}$l.5mm$^2$ pixellated anodes. Since the detector is smaller than imaged object, we translated it in an arc centered at the x-ray tube to image larger objects. Pulse counting electronics with very short shaping time (50 ns) are used to satisfy high photon rates in x-ray imaging, and response linearity up to 3${\times}$10$\^$5/ counts per second per detector element is achieved. The energy resolution of 122-keV gamma-ray is measured to be 14%. We have characterized the system performance by scanning a radiographic resolution phantom .and the Hoffman brain phantom. The spatial resolution of CT and SPECT are about 1 mm and 7 mm, respectively.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.661-666
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• 2009

Purpose : To determine the prevalence and clinical features of codetected respiratory etiological agents for acute respiratory infection in hospitalized children. Methods : Nasopharyngeal aspirates were obtained from hospitalized children with acute respiratory infection at Dankook University Hospital from September 2003 through June 2005. Immunofluorescent staining and culture were used for the detection of respiratory viruses (influenza virus [IFV] types A, B; parainfluenza virus [PIV] types 1, 2, 3; respiratory syncytial virus [RSV]; adenovirus [AdV]). Polymerase chain reaction (PCR) assays were used for Mycoplasma pneumoniae (MP) and Chlamydia trachomatis (CT) detection, and PCR and culture were performed for enterovirus detection. Acid-fast staining and culture were performed for tuberculosis detection. The demographic and clinical characteristics were reviewed retrospectively from the patients medical records. Results : Evidence of two or more microbes was found in 28 children: RSV was detected in 14, PIV 3 in 10, AdV in 10, MP in 8, PIV 2 in 8, CT in 4, and PIV 1 in 3. Codetected agents were found as follows: RSV＋PIV 2, 6 patients; AdV＋MP, 4 patients; AdV＋PIV, 3 patients; RSV＋MP, 3 patients; PIV 1＋PIV 3, 3 patients. Distinct peaks of codetected agents were found in epidemics of MP and each respiratory virus. Conclusion : The codetected infectious agents were RSV, PIV, AdV, and MP, with distinct peaks found in epidemics of MP and each respiratory virus. Although advances in diagnostic methods have increased the prevalence of codetection, its clinical significance should be interpreted cautiously.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.537-543
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• 2022

The purpose of this simulation study was to evaluate the possibility of pancreas detection through effective atomic number information using dual-energy computed tomography(CT). The effective atomic number of 10 tissue-equivalent materials were estimated through stoichiometric calibration. For stoichiometric calibration, HU values at low-energy (80 kV) and high-energy (140 kV) for 10 tissue-equivalent materials were used. Based on this method, the effective atomic number image of the tissue-equivalent material was extracted through an iterative algorithm. According to the results, the attenuation ratio in accordance with the effective atomic number was estimated to have an R² value of 0.9999, and the effective atomic number of Pancreas, Water, Liver, Blood, Spongiosa, and Cortical bone was overall within 1% accuracy compared to the theoretical value. Conventional pancreatic cancer examination uses a contrast medium, so there is a possibility of potential side effects of the contrast medium. In order to solve this problem, it is thought that it will be possible to contribute to an accurate and safe examination by extracting the effective atomic number using dual-energy CT without contrast enhancement. Based on this study, future research will be conducted on the detection of pancreatic cancer using the HU value of pancreatic cancer based on clinical images.

• Imaging Science in Dentistry
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• v.34 no.1
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• pp.13-18
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• 2004

Purpose : This study was to evaluate the influence of slice thickness of computed tomography (CT) and rapid protyping (RP) type on the accuracy of 3-dimensional medical model. Materials and Methods: Transaxial CT data of human dry skull were taken from multi-detector spiral CT. Slice thickness were 1, 2, 3 and 4 mm respectively. Three-dimensional image model reconstruction using 3-D visualization medical software (V-works /sup TM/ 3.0) and RP model fabrications were followed. 2-RP models were 3D printing (Z402, Z Corp., Burlington, USA) and Stereolithographic Apparatus model. Linear measurements of anatomical landmarks on dry skull, 3-D image model, and 2-RP models were done and compared according to slice thickness and RP model type. Results: There were relative error percentage in absolute value of 0.97, 1.98,3.83 between linear measurements of dry skull and image models of 1, 2, 3 mm slice thickness respectively. There was relative error percentage in absolute value of 0.79 between linear measurements of dry skull and SLA model. There was relative error difference in absolute value of 2.52 between linear measurements of dry skull and 3D printing model. Conclusion: These results indicated that 3-dimensional image model of thin slice thickness and stereolithographic RP model showed relative high accuracy.