• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.903-906
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• 1995

In this paper,human body models have been manufactured by the use of rapid prototyping techniques, which are to be used for surgery planning in clinical practice. In this manufactacturing process, CT or MRI data of human bodies are prepared and the images are processed to obtain sectional contours. With these contours, three-dimensional surface triangulated models are constructed, which finally transformed to STL file for rapid prototyping. For this purpose, total service system for manufacturing of human body models is constructed by employing commercial softwares, and the related problems and process parameters are investigated

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2003년도 추계학술대회 및 정기총회
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• pp.201-206
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• 2003

In clinical practice, CT Angiography is a powerful technique for the visualziation of blood flow in arterial vessels throughout the body. However CT Angiography images of blood vessels anywhere in the body may be fuzzy if the patient moves during the exam. In this paper, we propose a novel technique for removing global motion artifacts in the 3D space. The proposed methods are based on the two key ideas as follows. First, the method involves the extraction of a set of feature points by using a 3D edge detection technique based on image gradient of the mask volume where enhanced vessels cannot be expected to appear, Second, the corresponding set of feature points in the contrast volume are determined by correlation-based registration. The proposed method has been successfully applied to pre- and post-contrast CTA brain dataset. Since the registration for motion correction estimates correlation between feature points extracted from skull area in mask and contrast volume, it offers an accelerated technique to accurately visualize blood vessels of the brain.

• 정보처리학회논문지:컴퓨터 및 통신 시스템
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• 제12권3호
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• pp.119-126
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• 2023

근감소증은 국내는 2021년 질병으로 분류되었을 만큼 잘 알려져 있지 않지만 고령화사회에 진입한 선진국에서는 사회적 문제로 인식하고 있다. 근감소증 진단은 유럽노인근감소증 진단그룹(EWGSOP)과 아시아근감소증진단그룹(AWGS)에서 제시하는 국제표준지침을 따른다. 최근 진단방법으로 절대적 근육량 이외에 신체수행평가로 보행속도 측정과 일어서기 검사 등을 통하여 근육 기능을 함께 측정할 것을 권고하고 있다. 근육량을 측정하기 위한 대표적인 방법으로 DEXA를 이용한 체성분 분석 방법이 임상에서 정식으로 실시하고 있다. 또한 MRI 또는 CT의 복부 영상을 이용하여 근육량을 측정하는 다양한 연구가 활발하게 진행되고 있다. 따라서 본 논문에서는 근감소증 진단을 위해서 비교적 짧은 촬영시간을 갖는 CT의 복부영상기반으로 AI 영상 분할 모델을 개발하고 다기관 검증한 내용을 기술한다. 우리는 CT 영상 중에 요추의 L3 영역을 분류하여 피하지방, 내장지방, 근육을 자동으로 분할할 수 있는 인공지능 모델을 U-Net 모델을 사용하여 개발하였다. 또한 모델의 성능평가를 위해서 분할영역의 IOU(Intersection over Union)를 계산하여 내부검증을 진행했으며, 타 병원의 데이터를 활용하여 동일한 IOU 방법으로 외부검증을 진행한 결과를 보인다. 검증 결과를 토대로 문제점과 해결방안에 대해서 검증하고 보완하고자 했다.

• Nutrition Research and Practice
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• 제4권2호
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• pp.128-135
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• 2010

Obesity was characterized in Korean elementary students using different obesity assessment tests on 103 overweight elementary students from three schools of Jeonbuk Province. The body mass index (BMI) and obesity index (OI) were compared, and the data using DEXA and CT were compared with the data using BIA and a tape measure. The results of this study are as follows: first, 27 students who were classified as obese by OI were classified as overweight by BMI, and 3 students who were classified as standard weight by BMI were classified as overweight by OI. Secondly, by DEXA and BIA measurements, there was 1.51% difference in body fat percentage (boys 1.66%, girls 1.17%) and the difference in body fat mass between boys and girls was 0.77 kg (boys 0.85 kg, girls 0.59 kg), but those differences in body fat percentage and mass were not statistically significant. Thirdly, the average total abdominal fat (TAF) measured by CT scans of obese children was more significantly related with subcutaneous fat (r = 0.983, P < 0.01) than visceral fat (r = 0.640, P < 0.01). Also, TAF were highest significant with waist circumference by a tape measure (r = 0.744, P < 0.01). In summary, as there are some differences of assessment results between two obesity test methods (BMI, OI), we need more definite standards to determine the degree of obesity. The BIA seems to be the most simple and effective way to measure body fat mass, whereas waist/hip ratio (WHR) using a tape measurer is considered to be the most effective method for assessing abdominal fat in elementary students.

• 여성건강간호학회지
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• 제19권1호
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• pp.1-12
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• 2013

Purpose: This study was performed to propose an ontology methodology based on standardized nursing process as framework in obstetric and gynecologic nursing practice. Methods: The instrument used in this study was based on the nursing diagnosis classification established by North American Nursing Diagnosis Association (NANDA) (2009-2011), fifth edition of the Nursing Interventions Classification (NIC) (2008), forth edition of the Nursing Outcomes Classification (NOC) (2008) developed by Iowa State University and systematized nomenclature of medicine clinical terms (SNOMED CT). The nursing records data were collected from electronic medical records of one hospital from August to October 2010. Results: One hundred and forty-one nursing diagnosis statements used in obstetric and gynecologic nursing unit were linked standardized nursing classifications and constructed nursing diagnosis ontology including interoperability. Conclusion: Not only will this result be helpful to complete nurse's lack of knowledge and experience, it will also help to determine nursing diagnosis logically by using standardized nursing process. It will be utilized as the method to construct ontology including interoperability in other nursing units. It will be presented nursing interventions according to nursing diagnosis and thus will be easier to establish nursing planning. This can provide immediate feedback of the nursing process application.

• Nutrition Research and Practice
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• 제11권5호
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• pp.388-395
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• 2017

BACKGROUND/OBJECTIVES: Although Korean fermented foods contain large amounts of salt, which is known to exacerbate health problems, these foods still have beneficial effects such as anti-hypertension, anti-cancer, and anti-colitis properties. We hypothesized that ganjang may have different effects on blood pressure compared to same concentrations of salt. MATERIALS/METHODS: Sprague-Dawley rats were divided into control (CT), NaCl (NC), and ganjang (GJ) groups and orally administered with 8% NaCl concentration for 9 weeks. The systolic blood pressure (SBP), serum chemistry, $Na^+$ and $K^+$ concentrations and renal gene expressions were measured. RESULTS: The SBP was significantly increased in the NC group compared to the GJ and CT groups. In addition, the $Na^+$ concentration in urine was higher in the GJ and NC groups than the CT group, but the urine volume was increased in the GJ group compared to the other groups. The serum renin levels were decreased in the GJ group compared to the CT group, while the serum aldosterone level was decreased in the GJ group relative to the NC group. The mRNA expression of the renin, angiotensin II type I receptor, and mineralocorticoid receptor were significantly lower in the GJ group compared to other groups. Furthermore, GJ group showed the lowest levels of genes for $Na^+$ transporter in kidney cortex such as $Na^+/K^+$ $ATPase{\alpha}1$ ($NKA{\alpha}1$), $Na^+/H^+$ exchanger 3 (NHE3), $Na^+/HCO_3{^-}$ co-exchanger (NBC), and carbonic anhydrases II (CAII). CONCLUSIONS: The decreased SBP in the GJ could be due to decreased renin and aldosterone levels in serum and increased urinary volume and excretion of $Na^+$ with its transporter gene alteration. Therefore, ganjang may have antihypertensive effect despite its high contents of salt.

• Journal of Microbiology and Biotechnology
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• 제30권11호
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• pp.1688-1696
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• 2020

Soil physical and chemical characteristics, soil potential denitrification rates (PDR), community composition and nirK-, nirS- and nosZ-encoding denitrifiers were studied by using MiSeq sequencing, quantitative polymerase chain reaction (qPCR), and terminal restriction fragment polymorphism (T-RFLP) technologies base on short-term (5-year) tillage field experiment. The experiment included four tillage treatments: conventional tillage with crop residue incorporation (CT), rotary tillage with crop residue incorporation (RT), no-tillage with crop residue retention (NT), and rotary tillage with crop residue removed as control (RTO). The results indicated that soil organic carbon, total nitrogen and NH₄⁺-N contents were increased with CT, RT and NT treatments. Compared with RTO treatment, the copies number of nirK, nirS and nosZ in paddy soil with CT, RT and NT treatments were significantly increased. The principal coordinate analysis indicated that tillage management and crop residue returning management were the most and the second important factors for the change of denitrifying bacteria community, respectively. Meanwhile, this study indicated that activity and community composition of denitrifiers with CT, RT and NT treatments were increased, compared with RTO treatment. This result showed that nirK, nirS and nosZ-type denitrifiers communities in crop residue applied soil had higher species diversity compared with crop residue removed soil, and denitrifying bacteria community composition were dominated by Gammaproteobacteria, Deltaproteobacteria, and Betaproteobacteria. Therefore, it is a beneficial practice to increase soil PDR level, abundance and community composition of nitrogen-functional soil microorganism by combined application of tillage with crop residue management.

• Journal of Gastric Cancer
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• 제4권2호
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• pp.95-108
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• 2004

This nationwide survey was conducted to evaluate the current status of clinical practice for gastric cancer patients in Korea. The Information Committee of the Korean Gastric Cancer Association (KGCA) sent questionnaires containing 45 items about the preoperative diagnosis, medical and surgical treatment, and postoperative follow-up for gastric cancer patients to all 298 KGCA members in 108 institutes. Response rates were $32.6\%$ (97/298) for individuals and $59.3\%$ (64/108) for institutes. Most university hospitals responded (response rate of university hospitals: $71.6\%$, 48/67). The preoperative staging work up was performed primarily by abdominal CT, followed by bone scans, abdominal ultrasound, endoscopic ultrasound, and so on. Gastric cancer patients with stages II, III, and IV usually received adjuvant chemotherapy after a curative operation. About half of the surgeons regarded 2 cm as a safe resection margin in early gastric cancer and 5 cm in advanced gastric cancer. More than half of surgeons usually performed a D2 lymph node dissection in early gastric cancer and D2+$\alpha$ lymph node dissection in advanced gastric cancer. About $20\%$ of surgeons performed less invasive surgery and/or function-preserving surgery, such as a pylorus-preserving gastrectomy, a laparoscopic wedge resection, or a laparoscopy-assisted distal gastrectomy.

• Korean Journal of Radiology
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• 제21권8호
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• pp.987-997
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• 2020

Objective: Measurement of the liver and spleen volumes has clinical implications. Although computed tomography (CT) volumetry is considered to be the most reliable noninvasive method for liver and spleen volume measurement, it has limited application in clinical practice due to its time-consuming segmentation process. We aimed to develop and validate a deep learning algorithm (DLA) for fully automated liver and spleen segmentation using portal venous phase CT images in various liver conditions. Materials and Methods: A DLA for liver and spleen segmentation was trained using a development dataset of portal venous CT images from 813 patients. Performance of the DLA was evaluated in two separate test datasets: dataset-1 which included 150 CT examinations in patients with various liver conditions (i.e., healthy liver, fatty liver, chronic liver disease, cirrhosis, and post-hepatectomy) and dataset-2 which included 50 pairs of CT examinations performed at ours and other institutions. The performance of the DLA was evaluated using the dice similarity score (DSS) for segmentation and Bland-Altman 95% limits of agreement (LOA) for measurement of the volumetric indices, which was compared with that of ground truth manual segmentation. Results: In test dataset-1, the DLA achieved a mean DSS of 0.973 and 0.974 for liver and spleen segmentation, respectively, with no significant difference in DSS across different liver conditions (p = 0.60 and 0.26 for the liver and spleen, respectively). For the measurement of volumetric indices, the Bland-Altman 95% LOA was -0.17 ± 3.07% for liver volume and -0.56 ± 3.78% for spleen volume. In test dataset-2, DLA performance using CT images obtained at outside institutions and our institution was comparable for liver (DSS, 0.982 vs. 0.983; p = 0.28) and spleen (DSS, 0.969 vs. 0.968; p = 0.41) segmentation. Conclusion: The DLA enabled highly accurate segmentation and volume measurement of the liver and spleen using portal venous phase CT images of patients with various liver conditions.

• 대한방사선기술학회지:방사선기술과학
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• 제34권2호
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• pp.105-116
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• 2011

두경부(Head & Neck) CT(Computed Tomography)검사에서 환자가 받는 피폭선량 측정을 위하여 인체등가물질로 만든 Rando phantom과 유리선량계를 이용하여 두경부 검사에 따른 환자의 흡수선량의 변화를 실험을 통하여 연구하였다. 인체두부모형을 안와신경(optic nerve), 교뇌(pons), 소뇌(cerebellum), 갑상선(thyroid)으로 나누어, 두경부(Head & Neck) 부위의 검사를 단독검사(Brain, 3D Facial, Temporal, Brain Angiography, 3D Cervical Spine)와 복합검사(Brain+Brain Angiography, Brain+3D Facial, Brain+Temporal, Brain+3D Cervical spine, Brain+3D Facial+Temporal, Brain+3D Cervical Spin+Angiography)로 구분하여 유효선량의 변화를 실험한 후 결과를 측정하였다. 단순 Brain검사와 Brain Angio검사에는 optic nerve에 유효 선량이 높게 분석되었으며, 또한 Temporal검사에는 Pons에, 3D facial 검사와 3D Cervical Spin검사에는 thyroid의 유효선량 값이 높게 나타났다. 복합적으로 이루어는 검사 중 두경부의 Brain+Brain Angio의 검사는 cerebellum의 부위, Brain+3D facial 검사와 Brain+3D Cervical Spin의 복합검사는 thyroid의 부위, Brain+Temporal의 검사에는 pon's 부위 유효 선량 값이 높게 나타났다. Brain +3D facial +Temporal의 복합검사와 Brain+3D Cervical Spin+Angio의 복합검사는 thyroid의 부위에 유효 선량 값이 높게 분석 되었다. 본 연구 결과 Brain+3D Cervical Spin+Brain Angio 복합검사인 경우의 유효 선량은 2.51858 mSv로 일반인의 연간 유효선량한도 1 mSv의 피폭을 초과하는 결과가 나왔다. 또한, Brain 단순 검사 시 optic nerve는 0.31312 mSv의 유효선량으로 향후 방사선학 검사가 이루어질 경우, 두경부의 일반인의 연간 유효선량을 훨씬 초과할 것이라 사료된다. 따라서 진료의 필요성에 의해서 시행되는 CT검사일지라도 질환 병변의 특성에 맞게 CT촬영조건 변화를 주면서 환자의 피폭선량을 최소한으로 할 수 있는 다양한 검사방법의 연구가 필요하다고 사료된다.