• Journal of the Korean Society of Radiology
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• v.12 no.4
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• pp.525-532
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• 2018

This study is filmed by applying the axial angle variation of the X-ray tube instead of the patient's position change during the perimetric examination of the ribs. A Reference image with the rib oblique examination using a chest phantom and experimental images applied with a six-phase variation in the axial angle by increasing $5^{\circ}$ tube angle each from $5^{\circ}{\sim}30^{\circ}$ from the vertical incident direction of the chest phantom to the right horizontal axis were obtained. For the quantitative comparative evaluation of the images, SNR and CNR were calculated for regions of interest in the experimental images based on the reference image. Also, the left-right rib ratio in the reference image and the left-right rib ratio in the experimental images are measured and compared. As a result of the study, the experimental images with a tube angle of $25^{\circ}$ were best shown in the measurements of the SNR, CNR and left-right rib ratio compared to the reference image with a standard examination method. The modified rib examinations will consider useful, if it is difficult to maintain the patient's examination position.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.4
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• pp.619-626
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• 1998

This paper presents the features for quantitative evaluation of medical images based on the technique of image processing. In consideration of advice from medical doctor, 1 derive three features seemed to be strongly correlated with the degree of disease's advance. From comparison between each feature and evaluation value by medical doctor, our research shows that three features can be a useful aids in quantitative evaluation of lung's disease on chest X-ray images.

• Journal of Biomedical Engineering Research
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• v.9 no.2
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• pp.185-194
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• 1988

The dual-energy technique win used to separate the bone-only and tissue-only images from the conventional chest images. The equivalent thickness of the basic materials are estimated from low and high energy images of a given complex materials using the attenuation coefficient of ma serial componens. We showed that the image quality of dual-energy imaging method can be influenced by the ponlinearity and noise components of system and spectrum distributions The quantitative analysis of Calcium component was performed by dual-energy technique and it is shown that the concentration of the Calcium could be accurately estimated within 5% error range.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.661-672
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• 2022

After the outbreak of the SARS-CoV2 virus that causes COVID-19, it spreads around the world with the number of infections and deaths rising rapidly caused a shortage of medical resources. As a way to solve this problem, chest X-ray diagnosis using Artificial Intelligence(AI) received attention as a primary diagnostic method. The purpose of this study is to comprehensively analyze the detection of COVID-19 via AI. To achieve this purpose, 292 studies were collected through a series of Classification methods. Based on these data, performance measurement information including Accuracy, Precision, Area Under Cover(AUC), Sensitivity, Specificity, F1-score, Recall, K-fold, Architecture and Class were analyzed. As a result, the average Accuracy, Precision, AUC, Sensitivity and Specificity were achieved as 95.2%, 94.81%, 94.01%, 93.5%, and 93.92%, respectively. Although the performance measurement information on a year-on-year basis gradually increased, furthermore, we conducted a study on the rate of change according to the number of Class and image data, the ratio of use of Architecture and about the K-fold. Currently, diagnosis of COVID-19 using AI has several problems to be used independently, however, it is expected that it will be sufficient to be used as a doctor's assistant.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04a
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• pp.767-770
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• 2002

일반적으로 방사선 의사들(radialogists)이 폐 노쥴(pulmonary nodule)을 탐지하는 데는 실제적으로 30%의 실패율을 가진다고 알려져 있다. 만약 자동화된 시스템이 체스트 영상에서 의심스런 노쥴들의 위치들을 방사선 의사에게 알려줄 수 있다면 잘못 판단되는 노쥴들의 수를 잠재적으로 줄일 수 있다. 우리는 형태학적 필터들(morphological filters)과 두가지 특징-추출(feature-extraction) 기술들을 포함하는 컴퓨터 자동 처리 시스템을 구현하였다. 본 시스템에서는 첫째로 형태학적 필터(morphological filtering) 처리를 행한다. 이 과정은 원래의 영상에 침식(erosion)과 확장 (dilation)을 연이어서 행하는 것으로 처리가 어려운 X 선 영상을 좀 더 다루기 쉬운 상태로 바꿔주는 역할을 하게 된다. 둘째는 일차적으로 노쥴로서 컴퓨터에 선택된 의심 부분에 가해주는 특징-추출 테스트로서 이 작용은 노쥴로 감지되었으나 실제로는 노쥴이 아닌 경우인 false-positive 갑지들을 줄이기 위해서 사용된다. 그리하여 본 시스템은 노쥴의 정확한 판독이 어려운 폐의 X 선 영상에 적용되어 false-positive 들을 효과적으로 줄임으로써 보다 효율적인 폐 노쥴의 탐지를 가능하게 하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.7
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• pp.1573-1582
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• 2011

Risk of lung cancer among lung-related diseases has gradually increased during last decades. The chest digital radiography is the primary diagnosis method for lung cancer. Diagnosing lung cancer using this method requires doctors of ripe experience. Despite their experience there are often wrong diagnoses, which decrease early diagnosis and survival rates of patients. The aim of this study was intended to establish the base on the Computer Aided Diagnosis (CAD) by analyzing Image Recognition Algorithm using Principle component Analysis (PCA) and diagnosing patient's chest X-ray image. The database obtained through this approach enables a doctor to significantly reduce misdiagnosis during the early diagnosis stage, if he or she utilizes it as the preliminary reading step. Case studies were carried out using normal organ, and organs suffering from bronchogenic carcinoma and granuloma. A normal image and unique disease images were extracted after PCA analysis, and their cross-recognition efficiency were compared each other. The result revealed that the recognition rate was much high between normal and disease images, but relatively low between two disease images. In order to increase the recognition efficiency among chest diseases the related algorithms have to be developed continuously in the future study, and such effort will establish the resolute base for CAD.

• Journal of Digital Convergence
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• v.14 no.9
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• pp.331-339
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• 2016

Chronic diseases are increasing nowadays as daily habits changed due to economic growth. Among chronic diseases, heart cerebrovascular disease is one of the major causes of death in South Korea that accounts for approximately 20% of mortality. Tests to measure anomaly of the heart is ECG tests, which measures and analyzes the electrical heart activity. Any mistakes in lead attachment location critically affects ECG testings, and statistical facts showed that only 2.8% of the nurses properly located leads to patients. As a solution, this paper proposes a system based on a projection-based augmented reality technology to generate X-ray images to the patient's chest to point out exact attachment locations of ECG leads. Evaluation comparison results showed a 2.6 cm difference between the conventional system and the proposed system. ECG test results also showed significant signal differences between the systems in leads V1, V2, and V3. The ECG measured accurately by the proposed system would help greatly in patient management and clinical decisions of clinicians.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1139-1147
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• 2023

The purpose of this paper is to present and evaluate the performance of a method for controlling the dose for optimal image acquisition while minimizing patient exposure by applying a small-sized Photomultiplier(SiPM) sensor inside a portable detector. Portable detectors have the advantage of being able to quickly access the patient's location for rapid diagnosis, but this mobility comes with the challenge of dose control. This paper presents a method to identify the dose that can have the DQE and optimal image quality of the detector through image evaluation based on IEC62220-1-1, an international standard for X-ray imaging devices, and to identify the optimal dose by matching the ADU of the image and the output of the SiPM Sensor. The Skull AP image was acquired by implementing the detector manufacturer's reference dose. The optimal dose was 342.8 µGy, and the optimal controlled dose was 148.3 µGy, which is 57 % of the manufacturer's reference dose. The Chest AP image was 81.9 µGy and the optimal controlled dose was 27.9 µGy, which is a high dose reduction effect of 66 %. In addition, the two images were analyzed by five radiologists and found to have no clinically significant difference in anatomical delineation.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.634-651
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• 2021

Dynamic X-ray (DXR) is a functional imaging technique that uses sequential images obtained by a flat-panel detector (FPD). This article aims to describe the mechanism of DXR and the analysis methods used as well as review the clinical evidence for its use. DXR analyzes dynamic changes on the basis of X-ray translucency and can be used for analysis of diaphragmatic kinetics, ventilation, and lung perfusion. It offers many advantages such as a high temporal resolution and flexibility in body positioning. Many clinical studies have reported the feasibility of DXR and its characteristic findings in pulmonary diseases. DXR may serve as an alternative to pulmonary function tests in patients requiring contact inhibition, including patients with suspected or confirmed coronavirus disease 2019 or other infectious diseases. Thus, DXR has a great potential to play an important role in the clinical setting. Further investigations are needed to utilize DXR more effectively and to establish it as a valuable diagnostic tool.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1227-1233
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• 2020

Synovial sarcoma is a malignant soft tissue tumor that usually involves the extremities, particularly near the knees; a synovial sarcoma originating in the chest wall is extremely rare. We describe a 26-year-old woman diagnosed with a synovial sarcoma originating in the chest wall, based on CT and MRI findings. Contrast-enhanced CT images revealed a small, well-defined enhancing mass with calcification, in the subpleural area. This lesion was initially diagnosed as a benign tumor; however, the patient developed sudden severe pain with spontaneous bleeding and hemothorax, suggesting the possibility of malignancy. MRI revealed a multilobulated mass with a fluid-fluid level, which characterizes a synovial sarcoma.