• Korean Journal of Radiology
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• 제20권1호
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• pp.50-57
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• 2019

In pediatric thoracic CT, respiratory motion is generally treated as a motion artifact degrading the image quality. Conversely, respiratory motion in the thorax can be used to answer important clinical questions, that cannot be assessed adequately via conventional static thoracic CT, by utilizing four-dimensional (4D) CT. However, clinical experiences of 4D thoracic CT are quite limited. In order to use 4D thoracic CT properly, imagers should understand imaging techniques, radiation dose optimization methods, and normal as well as typical abnormal imaging appearances. In this article, the imaging techniques of pediatric thoracic 4D CT are reviewed with an emphasis on radiation dose. In addition, several clinical applications of pediatric 4D thoracic CT are addressed in various thoracic functional abnormalities, including upper airway obstruction, tracheobronchomalacia, pulmonary air trapping, abnormal diaphragmatic motion, and tumor invasion. One may further explore the clinical usefulness of 4D thoracic CT in free-breathing children, which can enrich one's clinical practice.

• 한국정보통신학회논문지
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• 제18권11호
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• pp.2691-2696
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• 2014

SNOMED CT는 전자의무기록(EMR) 및 전자건강기록(EHR) 시스템에서 표준화된 용어를 사용하여 진로기록을 작성하고 관리하기 위한 표준 의학용어 체계이다. 이 용어체계는 용어의 방대함 및 설계 구조로 인해 용어 체계가 매우 복잡한 특징이 있다. SNOMED CT에서 제공하는 의학 용어를 검색하기 위해 진료 과정에서 사용하는 기존의 브라우저들은 용어체계의 복잡성을 반영하지 못하여 진료기록의 작성 단계에서 그 효용성이 떨어지는 문제가 있다. 본 연구에서는 SNOMED CT 브라우저에 내재된 문제점을 제시하고 용어체계의 분석을 통해 의학 용어를 빠르고 효율적으로 검색하기 위한 검색 브라우저의 요건을 분석하고 개선안을 제시한다.

• 한국간호교육학회지
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• 제22권3호
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• pp.304-315
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• 2016

Purpose: The purpose of this study was to explore the relationships of critical thinking disposition (CT), nursing work environment (NWE), and clinical decision making ability among nurses. Methods: A cross-sectional, descriptive study design was conducted on 192 nurses who had worked for more than six months in five general hospitals. A self-reported questionnaire was used to collect data, which included demographics, CT, NWE, and clinical decision making ability. Results: The mean score of CT was 3.5. The highest score was on the objectivity of CT and the lowest on systematicity. The mean score of NWE was 2.3. The highest score was on the collegial nurse-physician relations of NWE and the lowest on the staffing and resource adequacy. The mean score of clinical decision making ability was 3.3. In hierarchical multiple regression, affecting factors on clinical decision making ability were CT and NWE. Conclusion: The findings showed that clinical decision making ability is associated with CT and NWE. To improve clinical decision making ability, it is important to improve CT. In addition, it should be considered to improve NWE where the nurses can make a decision with their job through critical thinking.

• Korean Journal of Radiology
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• 제22권11호
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• pp.1749-1763
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• 2021

Coronary computed tomography angiography (CCTA) is routinely used for anatomical assessment of coronary artery disease (CAD). However, invasive measurement of fractional flow reserve (FFR) is the current gold standard for the diagnosis of hemodynamically significant CAD. CT-derived FFRCT and CT perfusion are two emerging techniques that can provide a functional assessment of CAD for risk stratification and clinical decision making. Several clinical studies have shown that the diagnostic performance of concomitant CCTA and functional CT assessment for detecting hemodynamically significant CAD is at least non-inferior to that of other routinely used imaging modalities. This article aims to review the current clinical evidence and recent developments in functional CT techniques.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 추계학술대회
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• pp.416-417
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• 2014

SNOMED CT는 전자의무기록(EMR) 시스템에서 진료기록을 표준화된 방법으로 기록 및 관리하기 위한 표준 의학용어 체계이다. 하지만, SNOMED CT는 그 표현의 다양성으로 인해 진단, 수술 등의 환자의 상태를 일관성 있게 작성하기가 매우 어려운 문제가 있다. 이는 동일한 임상적 의미가 다양한 용어 및 그 조합으로 표현되고 또한 동일한 용어임에도 다양한 임상적 의미가 내포될 수 있기 때문이다. 본 연구에서는 SNOMED CT에서 발생하는 용어의 중복성 문제를 분석하고 의학용어를 빠르고 효율적으로 검색하기 위한 검색 브라우저의 요구 조건을 제시한다.

• 대한임상검사과학회지
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• 제36권2호
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• pp.193-198
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• 2004

PET/CT combines the functional information from a positron emission tomography (PET) exam with the anatomical information from a computed tomography (CT) exam into one single exam. A CT scan uses a combination of x-rays and computers to give the radiologist a non-invasive way to see inside your body. One advantage of CT is its ability to rapidly acquire two-dimensional pictures of your anatomy. Using a computer these 2-D images can be presented in 3-D for in-depth clinical evaluation. A PET scan detects changes in the cellular function - how your cells are utilizing nutrients like sugar and oxygen. Since these functional changes take place before physical changes occur, PET can provide information that enables your physician to make an early diagnosis. The PET exam pinpoints metabolic activity in cells and the CT exam provides an anatomical reference. When these two scans are fused together, your physician can view metabolic changes in the proper anatomical context of your body. PET/CT offers significant advantages including more accurate localization of functional abnormalities, and the distinction of pathological from normal physiological uptake, and improvements in monitoring treatment. A PET/CT scan allows physicians to measure the body's abnormal molecular cell activity to detect cancer (such as breast cancer, lung cancer, colorectal cancer, lymphoma, melanoma and other skin cancers), brain disorders (such as Alzheimer's disease, Parkinson's disease, and epilepsy), and heart disease (such as coronary artery disease).

• 한국의학물리학회지:의학물리
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• 제32권1호
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• pp.1-17
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• 2021

The evolution of X-ray computed tomography (CT) has been based on the discovery of X-rays, the inception of the Radon transform, and the development of X-ray digital data acquisition systems and computer technology. Unlike conventional X-ray imaging (general radiography), CT reconstructs cross-sectional anatomical images of the internal structures according to X-ray attenuation coefficients (approximate tissue density) for almost every region in the body. This article reviews the essential physical principles and technical aspects of the CT scanner, including several notable evolutions in CT technology that resulted in the emergence of helical, multidetector, cone beam, portable, dual-energy, and phase-contrast CT, in integrated imaging modalities, such as positron-emission-tomography-CT and single-photon-emission-computed-tomography-CT, and in clinical applications, including image acquisition parameters, CT angiography, image adjustment, versatile image visualizations, volumetric/surface rendering on a computer workstation, radiation treatment planning, and target localization in radiotherapy. The understanding of CT characteristics will provide more effective and accurate patient care in the fields of diagnostics and radiotherapy, and can lead to the improvement of image quality and the optimization of exposure doses.

• Korean Journal of Radiology
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• 제22권7호
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• pp.1213-1224
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• 2021

Objective: To develop a machine learning (ML) pipeline based on radiomics to predict Coronavirus Disease 2019 (COVID-19) severity and the future deterioration to critical illness using CT and clinical variables. Materials and Methods: Clinical data were collected from 981 patients from a multi-institutional international cohort with real-time polymerase chain reaction-confirmed COVID-19. Radiomics features were extracted from chest CT of the patients. The data of the cohort were randomly divided into training, validation, and test sets using a 7:1:2 ratio. A ML pipeline consisting of a model to predict severity and time-to-event model to predict progression to critical illness were trained on radiomics features and clinical variables. The receiver operating characteristic area under the curve (ROC-AUC), concordance index (C-index), and time-dependent ROC-AUC were calculated to determine model performance, which was compared with consensus CT severity scores obtained by visual interpretation by radiologists. Results: Among 981 patients with confirmed COVID-19, 274 patients developed critical illness. Radiomics features and clinical variables resulted in the best performance for the prediction of disease severity with a highest test ROC-AUC of 0.76 compared with 0.70 (0.76 vs. 0.70, p = 0.023) for visual CT severity score and clinical variables. The progression prediction model achieved a test C-index of 0.868 when it was based on the combination of CT radiomics and clinical variables compared with 0.767 when based on CT radiomics features alone (p < 0.001), 0.847 when based on clinical variables alone (p = 0.110), and 0.860 when based on the combination of visual CT severity scores and clinical variables (p = 0.549). Furthermore, the model based on the combination of CT radiomics and clinical variables achieved time-dependent ROC-AUCs of 0.897, 0.933, and 0.927 for the prediction of progression risks at 3, 5 and 7 days, respectively. Conclusion: CT radiomics features combined with clinical variables were predictive of COVID-19 severity and progression to critical illness with fairly high accuracy.

• Nuclear Medicine and Molecular Imaging
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• 제42권3호
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• pp.253-255
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• 2008

A 61-year-old man had a F-18 FDG PET/CT scan for evaluation of a common bile duct cancer identified on CT. The PET/CT image showed a hypermetabolic mass in the common bile duct, and a focal area of increased F-18 FDG uptake in segment IV of the liver, which corresponded to a hypoattenuated lesion on non-enhanced CT, and was consistent with hepatic metastasis. The patient underwent choledochojejunostomy with hepatic resection, and pathologic findings were compatible with an eosinophilic abscess in the liver. This case demonstrates that F-18 FDG uptake by an eosinophilic abscess can mimic hepatic metastasis in a patient with a malignancy.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.323-325
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• 2014

SNOMED CT는 임상 과정에서의 진료 기록을 전산화하고 이를 효율적으로 관리 및 활용하기 위한 종합적 표준 임상 의학용어 체계이다. 그러나 이는 표현 가능한 용어의 종류가 지나치게 많음에 따라 환자 상태를 표현하는 가장 적합한 용어를 짧은 진료 시간 내에 선택하여 기록하기가 어렵고, 또한 한가지 임상적 의미가 다양한 용어 및 그 조합으로 표현될 수 있음에 따라 의무기록의 작성시 그 의미가 왜곡되거나 잘못 해석될 여지가 발생한다. 본 연구에서는 이러한 문제점들을 분석하고 이를 해결하기 위한 중복 용어 선택 기법을 제시한다.