• Journal of radiological science and technology
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• v.43 no.5
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• pp.397-404
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• 2020

Coronavirus disease(COVID-19) is highly infectious disease that directly affects the lungs. To observe the clinical findings from these lungs, the Chest Radiography(CXR) can be used in a fast manner. However, the diagnostic performance via CXR needs to be improved, since the identifying these findings are highly time-consuming and prone to human error. Therefore, Artificial Intelligence(AI) based tool may be useful to aid the diagnosis of COVID-19 via CXR. In this study, we explored various Deep learning(DL) approach to classify COVID-19, other viral pneumonia and normal. For the original dataset and lung-segmented dataset, the pre-trained AlexNet, SqueezeNet, ResNet18, DenseNet201 were transfer-trained and validated for 3 class - COVID-19, viral pneumonia, normal. In the results, AlexNet showed the highest mean accuracy of 99.15±2.69% and fastest training time of 1.61±0.56 min among 4 pre-trained neural networks. In this study, we demonstrated the performance of 4 pre-trained neural networks in COVID-19 diagnosis with CXR images. Further, we plotted the class activation map(CAM) of each network and demonstrated that the lung-segmentation pre-processing improve the performance of COVID-19 classifier with CXR images by excluding background features.

• Journal of Radiation Industry
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• v.12 no.4
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• pp.365-372
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• 2018

The use of CT examinations is increasing rapidly and radiation dose from CT examinations is much higher than other diagnostic radiography examinations including general radiography and mammography. DRLs used to optimize the radiation dose of patients by diagnostic radiology in each country. The objective of this study was to investigate and to analyze the status of DRLs from CT examinations in domestic and other countries. In other countries, DRLs were set for each age group and each examination considering the medical situation of each country. In Korea, DRLs were set for adults and children in 2017. For adults, DRLs were set for 13 examinations. Reported DLP values were 1119, 297, $472mGy{\cdot}cm$ for head, chest and abdomen pelvis examination, respectively. For children, DRLs were set for head examinations. Reported DLP values were 298 (0~1 years), 404 (2~5 years), 494 (6~10 years), 1,088 (11~15 years) $mGy{\cdot}cm$. DRLs of Korea were similar to other countries for head examinations. For chest examinations and abdomen pelvis examinations were relatively lower than other countries. As a major reason for relatively low radiation dose, it is considered to contribute the activity and management of medical radiation safety at national level.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.276-283
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• 2019

The purpose of this study is to evaluate the usefulness of automatic exposure control (AEC) by analyzing entrance surface dose (ESD) and entropy on using automatic exposure and manual exposure. The experimental method was to measure the dose by placing a semiconductor dosimeter on the Rando Phantom for the Pelvis, Abdomen, Skull, and Chest regions. The DICOM file was simultaneously acquired and then entropy was analyzed by using Matlab. As a result, when using the automatic exposure control, dose of all sites was lower than manual exposure's dose and entropy was high. In addition, paired t-test was performed for each item and p<0.05 was found in each item. In conclusion, the use of automatic exposure control can be a useful method to contribute to the optimization of the exposure dose and the image quality by reducing the amount of unnecessary radiation amount and information loss that can occur in X-ray examination.

• Korean Journal of Radiology
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• v.1 no.3
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• pp.135-141
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• 2000

Objective: To compare the clinical utility of the different imaging techniques used for the evaluation of tracheobronchial diseases. Materials and Methods: Forty-one patients with tracheobronchial diseases [tuberculosis (n = 18), bronchogenic carcinoma (n = 10), congenital abnormality (n = 3), post-operative stenosis (n = 2), and others (n = 8)] underwent chest radiography and spiral CT. Two sets of scan data were obtained: one from routine thick-section axial images and the other from thin-section axial images. Multiplanar reconstruction (MPR) and shaded surface display (SSD) images were obtained from thin-section data. Applying a 5-point scale, two observers compared chest radiography, routine CT, thin-section spiral CT, MPR and SSD imaging with regard to the detection, localization, extent, and characterization of a lesion, information on its relationship with adjacent structures, and overall information. Results: SSD images were the most informative with regard to the detection (3.95±0.31), localization (3.95±0.22) and extent of a lesion (3.85±0.42), and overall information (3.83±0.44), while thin-section spiral CT scans provided most information regarding its relationship with adjacent structures (3.56±0.50) and characterization of the lesion (3.51±0.61). Conclusion: SSD images and thin-section spiral CT scans can provide valuable information for the evaluation of tracheobronchial disease.

• 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.

• Korean Journal of Microbiology
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• v.19 no.3
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• pp.142-152
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• 1981

One hundred and thirteen healed pulmonary tuberculosis patients and 11 patients with other underlying diseases were studied for evidence of pulmonary fungal infection because of persisting hemoptysis or chronic cough. Rediological, mycological and serological investigations revealed that 54 out of 124 patients were evidently infected with one or more species of fungi. A. fumigatus was isolated from 4 out of 70 patients whose sera did not react with antigens from this fungus, while it was isolated from 43 out of 47 serological reactors to this fungus. Chest radiography showed a distinct fungus ball in a cyst of one patient and in a preformed cavity in the lung of 17 healed tuberculosis patients and two other patients. The latter two patients were infected with A.flavus. Two patients, who were under the long period of immunosuppressive therapy, apparently succumbed to invasive aspergillosia due to A.fumigatus. A single or dual infection with A. flavus, A. nidulans, A.nidulans var. latus, C. albicans, and P. boydii were noticed in some patients without mycetomal shadow on chest radiographs. Young mycelial extract (ME) of A.fumigatus detected antibody in 95.8 percent of the sera from patients infected with this fungus, while it was isolated from 43 out of 47 serological reactors to this fungus. Chest radiography showed a distinct fungus ball in a cyst of one patient and in a performed cavity in the lung of 17 healed tuberculosis patients and two other patients. The latter two patients were infected with A. flavus. Two patients, who were under the long period of immunosuppressive therapy, apparently succumbed to invasive aspergillosis due to A.fumigatus. A single or dual infection with A. flavus, A. nidulans, A. niduans var. latus, C. albicans, and P. boydii were noticed in some patients without mycetomal shadow on chest radiographs. Young mycelial extract (ME) of A.fumigatus detected antibody in 95.8 percent of the sera from patients infected with this fungus, while the commercial culture filtrate antigen (GL) yielded 78.7 per cent positive result. Culture filtrate antigen, however, was comparable with ME. There was no single antigen with which all the serum specimens reacted. Fractionation of ME resulted in a loss of some activity although it excluded substances that reacted with C-reactive protein in a loss of some activity although it excluded substances that reacted with C-reactive protein. Most reactive and specific precipitinogens distributed in the fraction (FB) which was precipitable at 75 percent saturation with ammonium sulfate and eluted in a second peak in order from gel-filtration and which contained mostly proteinic components. Glycoproteins or polysaccharides rich fractions (FA and ASI) were relatively less effective in detecting antibody. Demonstration of antibody in the serum from patients using a battery of fungal antigens and of etiologically related fungi from clinical specimens are very useful laboratory procedures for the diagnosis of pulmonary fungal infection which is a common complication of tuberculosis.

• The Korean Journal of Nuclear Medicine
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• v.25 no.1
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• pp.46-52
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• 1991

Radioaerosol inhalation imaging (RII) has been used in radionuclide pulmonary studies for the past 20 years. The method is well accepted for assessing regional ventilation because of its usefulness, easy fabrication and simple application system. To evaluate its clinical utility in the study of impaired regional ventilation in bronchial asthma, we obtained and analysed RIIs in 31 patients (16 women and 15 men; age ranging 21-76 years) with typical bronchial asthma at the Department of Radiology, Kangnam St. Mary's Hospital, Catholic University Medical college, from January, 1988 to August, 1989. Scintiscans were obtained with radioaerosol produced by a BARC(Bhabha Atomic Reserch Center, India) nebulizer with 15 mCi of $^{99m}Tc-phytate$. The scanning was peformed in anterior, posterior and lateral projections following 5-minute inhalation of radioaerosol on sitting position. The scans were analyzed and correlated with the results of pulmonary function study and the findings of chest radiography. Fifteen patients had concomitant lung perfusion image with $^{99m}Tc-MAA$. Follow-up scans were obtained in 5 patients after bronchodilator therapy. The patients were divided into (1) attack type (4 patients), (2) resistant type (5 patients), (3) remittent type (10 patients) and (4) bronchitic type (12 patients). Chest radiography showed hyperinflation, altered pulmonary vascularity, thickening of the bronchial wall and accentuation of basal interstitial markings in 26 of the 31 patients. Chest radiographs were norma! in the remaining 5 patients. Regardless of type, the findings of RII were basically the same, and characterized by the deposition of radioaerosol in the central parts or in the main respiratory air ways along with mottled nonsegmental ventilation defects in the periphery. Peripheral parenchymal defects were more extensive than that of expected findings from clinical symptoms, pulmonary function test and chest radiograph. Broomstick sign was present in 17 patients. The abnormality of RII was poorly correlated with perfusion scans. In all 5 patients treated with bronchodilators, follow-up study demonstrated a decrease in the degree of radioaerosol deposition in the central air way with improved ventilation defects. This study indicates that RII is a useful technique for the evaluation of regional ventilation abnormality and the effect of treatment with bronchodilators in patients with bronchial asthma.

• Journal of the Korean Society of Radiology
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• v.12 no.4
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• pp.519-524
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• 2018

Chest examinations and mass chest examinations using the CR(computed radiography) System are frequently used clinically. a factor that degrades image quality in the acquisition process is the use of unused IPs long times. this paper addresses the estimation of winer filter and improved wiener filter to restoration of Chest CR images Experimental results show that the proposed method can reduce noise. in low noise variation image wiener method was excellent than improved method and the result was the opposite at high noise varience. the application of algorithms to chest CR images effectively eliminates noise. the classic Wiener filter was better than the improved method. Multiple patients examined during the process without any erase IP(image plate) process, The proposed algorithm determines that the images can be restored to a good quality and will help to read the images.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1243-1246
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• 1998

Tracheobronchial injuries are uncommon. Except for the cervical region, most tracheobronchial injuries are due to blunt chest trauma in Korea. The depth of the tracheobronchial trees renders these structures relatively safe from stab wound. We experienced a case of left main bronchial laceration with azygos vein tear following stab wound in the back of right chest firstly in Korea. The patient was a 24 years old male. A routine chest radiography showed a knife in chest at emergency room. We didn't remove the knife at emergency room. This patient was carried to operation room in 30 minutes after arrival of our hospital without computed tomography and bronchoscopy. The operation was performed through standard right posterolateral thoracotomy and then the knife was removed. The left main bronchus and azyos vein were lacerated obliquely. The penetrated azygos vein was ligated and the laceration of the left main bronchus was repaired. Postoperative course was uneventful.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.249-255
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• 2016

This study, Seoul City shelter, you are trying to seek medical cooperation and cure rate increase proposal Yu findings's current situation and tuberculosis of homeless tuberculosis. Inspector, and has a total 591 people is targeted to implement an interview after acquiring utilization agreement in studies conducted chest X-ray photography. Of the interview questions, three or more protons, it is determined that the TB symptomatic conducted sputum examination, chest X-ray examination confirms the physician radiology, when sputum examination primarily chromatic findings the double implemented and conducted by requesting the ship inspection also said inspection sputum acid-fast bacteria if it is true one, respectively. confirmed case result of checking whether there is a difference due to risk factors(Jb) at the chi square black, it was found that there is no statistically significant difference at 95% confidence level. (${\chi}^2=0.276$, p>0.05), suspected case (Ac, Ae) results of examining whether there is a difference due to risk factors in chi square black, that there is a statistically significant difference at 99% confidence level is I found (${\chi}^2=9.414$, p<0.01). The nature of the homeless tuberculosis screening and directed to the distance homeless specific location are likely to evaluate the actual incidence low and aggressive or management needs, the rationale is allowed insufficient reality is. Through this research, future, for tuberculosis high risk tuberculosis patient, such as homeless to expand the tuberculosis screening of infectious tuberculosis patients in private medical institutions, and one-stop service that chest X-ray examination and sputum examination is carried out at the same time introduced immediately to prevent the inspection and examination, cure, and should establish a foundation that can be up to post administration.