• Tuberculosis and Respiratory Diseases
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• v.40 no.4
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• pp.449-453
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• 1993

A 64-year-old male was admitted due to abruptly developed, severe dyspnea via local clinic. He had been a heavy smoker and alcoholic for a long time. Chest PA showed huge haziness in right upper lung field. Sputum culture for bacteriology was positive for Klebsiella pneumoniae. Immediately, appropriate antibiotics were administered and artificial ventilation was started. On 40th hospital day, simple chest roentgenogram taken due to sudden aggravated dyspnea showed marked hyperlucency in right upper lung field, suggestive of rupture of abscess cavity and resultant pneumothorax. At that time, chest tube was inserted but air leakage from the chest tube persisted. Chest CT scan taken after chest tube insertion showed the tube inserted into a thin-walled cavity in the above lesion. on 84th hospital day, right upper lobectomy with decortication was performed. Pathologically, cavittary lung abscess was diagnosed on the findings of partial re-epithelialization of ciliated columnar epithelium with severe pulmonary vascular occlusion and extensive fibrous pleural adhesions.

• Tuberculosis and Respiratory Diseases
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• v.44 no.3
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• pp.649-654
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• 1997

Benign solitary schwannoma of the chest wall is a rare disease of nerve sheath origin A 43-year-old female patient was admitted to our hospital for right upper quandrant pain Chest X-ray shows nonspecific finding, ultrasonography & CT scan revealed a solid tumor on the right lateral chest wall. On aspiration needle biopsy, this mass was turned out to be a schwannoma of the right lateral chest wall. This mass was excised surgically in an encapsulated state by right lateral thoracotomy. Histological section revealed a typical schwannoma, which is characterized by Antoni A and Antoni B tissues of high & low cellularity.

• Journal of radiological science and technology
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• v.43 no.6
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• pp.503-509
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• 2020

This study aims to develop a patient-specific radiation exposure dose prediction model based on anthropometric data that can be easily measurable during CT examination, and to be used as basic data for DRL setting and radiation dose management system in the future. In addition, among the machine learning algorithms, the most suitable model for predicting exposure doses is presented. The data used in this study were chest CT scan data, and a data set was constructed based on the data including the patient's anthropometric data. In the pre-processing and sample selection of the data, out of the total number of samples of 250 samples, only chest CT scans were performed without using a contrast agent, and 110 samples including height and weight variables were extracted. Of the 110 samples extracted, 66% was used as a training set, and the remaining 44% were used as a test set for verification. The exposure dose was predicted through random forest, linear regression analysis, and SVM algorithm using Orange version 3.26.0, an open software as a machine learning algorithm. Results Algorithm model prediction accuracy was R^2 0.840 for random forest, R^2 0.969 for linear regression analysis, and R^2 0.189 for SVM. As a result of verifying the prediction rate of the algorithm model, the random forest is the highest with R^2 0.986 of the random forest, R^2 0.973 of the linear regression analysis, and R^2 of 0.204 of the SVM, indicating that the model has the best predictive power.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.29-34
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• 2012

Purpose : Presently, hardwares and softwares for reducing radiation exposure are continually developed for PET/CT examination. Purpose of this study is to evaluate effectiveness of reducing radiation exposure dose of CT and SUV changes of PET when applied each kernel to ACCT (Attenuation Correction Computed Tomography) according to adopted IRIS (Iterative Reconstruction in Image Space) software. Materials and Methods : Biograph mCT (Siemens, Germany) was used as a PET/CT scanner. Using AAPM CT performance phantom, from standard (120 kVp, 100 mAs), 7 scans were conducted by reducing 15 mAs each. After image reconstruction by FBP (Filtered Back Projection) and IRIS, noise and spatial resolution were evaluated. The same method was applied to anthropomorphic chest phantom and acquired images were compared. NEMA IEC body phantom was used for SUV evaluation. Injected dose rate for hot sphere (hot) and background cylinder (BKG) were 1:8. CT dose condition (120 kVp, 50 mAs) was the same for each scan and PET scan durations were 1, 2, 3 and 4min. After scanning, each kernel of IRIS was applied to ACCT. And PET images were reconstructed by ACCT adopted IRIS for comparing SUV changes. Results : AAPM phantom test for noise evaluation, SD for FBP 100 mAs, IRIS 55 mAs were 8.8 and 8.9. FBP 85 mAs, IRIS 40 mAs were 9.5 and 9.7. FBP 70 mAs, IRIS 25 mAs were 11.9 and 11.1. Above mAs condition for FBP and IRIS, SD showed similar values. And for spatial resolution test, there was no significant difference. For chest phantom test, when applied the same mAs and kernel to both of FBP and IRIS, every applied kernels showed reduced noise. Lower mAs and higher kernel value showed higher noise reduction. There was no considerable difference only except for I70 very sharp kernel for SUV comparison using NEMA IEC body phantom. Conclusion : In this study, low mAs (55 mAs) applied IRIS and standard mAs (100 mAs) applied FBP showed similar noise. And only except for I70 kernel, there was no significant SUV changes. It is possible to reduce needless radiation exposure and acquire better image quality than FBP's through applying appropriate kernel of IRIS to PET/CT.

• Tuberculosis and Respiratory Diseases
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• v.55 no.6
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• pp.551-559
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• 2003

Background : Emergency management in hemoptysis is bronchial artery angiography and embolization. This study was designed to investigate the accuracy of localization of bleeding site by simple roentgenogram, computed tomography(CT) and bronchoscopy prior to embolization and to evaluate the outcome of embolotherapy. Method : We retrospectively evaluated 50 patients performed bronchial artery embolization(BAE), admitted to tertiary university hospital due to hemoptysis. Results : The most common causes were pulmonary tuberculosis, old tuberculous related parenchymal damage, aspergilloma, and bronchiectasis. The success rate of BAE within one month was 90%; within 3 months was 88%; during follow up period of mean 11.6 months was 76%. The concordant rate of simple roentgenogram with angiographic outcome in terms of bleeding site is 70%; in chest CT 80%; in bronchoscopy 81%; in combined information of simple roentgenogram and CT 83%; in combined information of simple roentgenogram and bronchoscopy 78%. Conclusion : The diagnostic accuracy for the bleeding site was similar between chest CT and bronchoscopy, showing high diagnostic yield. The success rate of BAE was comparative to prior studies. Further study will be needed in a large scale in near future.

• Journal of Chest Surgery
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• v.29 no.5
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• pp.569-572
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• 1996

A sixty nine-year-old mate patient was admitted with a chief complaint of exertional dyspnea. Lung perfusion scan revealed total perfusion defect of the of left lung and CT anglography showed the ab- rupt cutoff left pulmonary artery. He denied of trauma history, previous lower leg symptom and sign, or any embolic history. With the impression of chronic pulmonary thromboembolism of unknown etiology, operation was done under the cardiopulmonary bypass through a median sternotomy. After main pulmonary artery clamping and pulmonary arteriotomy, thromboembolectomy was done. Postoperative lung perfusion scan and CT angiography showed near normal left pulmonary blood flow. The patient was discharged on the postoperative 9th day without any postoperative complication.

• Korean Journal of Bronchoesophagology
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• v.4 no.1
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• pp.59-63
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• 1998

Background： Unilateral vocal cord paralysis(UVCP) by recurrent laryngeal nerve injury is one of the common laryngological diseases. Objectives : We attempted to study the clinical feature and the causes of UVCP and also tried to investigate what is to be the initial approach for determining the causes of unknown-origin UVCP Materials and methods The charts of 82 patients with the diagnosis of UVCP were reviewed. The records were analyzed for patient's gender and age, the status of paralysed vocal cord, the crucial tests for the diagnosis, and the etiologies. Results : forty-nine(59.8%) male and 33(40.2%) female patients were included in this study. The age group of sixth decade was most commonly involved. Most of the cases showed paramedian position of palsy, and the left side(59.8%) was more frequently attacked. The most common cause of UVCP in this series was the unknown origin, followed by the surgical trauma and neoplasms. The etiologies of the six(12.5%) unknown-cause cases were found with the further evaluation, with the most useful test being a CT scan. Conclusion： Chest X-ray, esophagography, and CT scan should be included in the mandatory initial investigation of patients with unknown-origin UVCP

• The Journal of Korean Society for Radiation Therapy
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• v.33
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• pp.47-54
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• 2021

Purpose : In order to evaluate the usefulness of clinical application of the Pause & Resume methods by comparing and analyzing the data stability and dose reduction effect when repeat scan assuming irregular breathing and using the Pause & Resume method during chest 4D CT using Quasar^TM Phantom. Materials and Methods : Using the Quasar^TM Phantom, set the breathing rate per minute to 15 BPM and 7.5 BPM, and set the S15 point as an irregular breathing section, and then placed OSLD to this point and use the Pause & Resume method to measure the dose of S15. CTDIvol, DLP, and ALARA-CT were used for comparative analysis of radiation dose between Pause & Resume method and Repeat-scan. In order to evaluate the stability and usability of the data applying the Pause & Resume method, the captured images were sorted by Advanced Workstation Volume Share7 and then sent to Eclipse^TM, the diameter and volume were analyzed by forming a contour on the iron ball in the Quasar^TM Phantom Results : When using Pause & Resume, the dose of OSLD measurement increased by 1.97 times in the section of S15. As a result of image evaluation, the average value of all volumes measured with and without the Pause & Resume method at 15 BPM and 7.5 BPM was 15.2 cm3±0.5%.Allthemeasuredvaluesfor the radius of iron ball were 3.1 cm regardless of whether Pause & Resume method was used or not. In the case of using Pause & Resume, 33% decreased from the lowest DLP value and 38% decreased from the highest DLP value of repeat scan, and the effective dose also decreased 32.1% from the minimum value and 37.6% from the maximum value. Conclusion: Irradiation dose was increased by Pause & Resume method because of the repeat scan on the S15 site where assuming irregular breathing occurred, However Pause & Resume method led to a significant reduction in dose on overall scan range. It also proved the usefulness of clinical application of the Pause & Resume method as a result of similar diameters and volumes of iron ball measurement.

• Journal of Chest Surgery
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• v.31 no.1
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• pp.89-91
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• 1998

Tuberculosis infection is wide spread disease and makes troublesome complications in some cases. A 50 - year old male visited Andong Hospital with coughing and sputum, dyspnea on exertion, bulging left anterior chest wall mass. Chest X-ray showed right pleural effusion, both side streaky infiltraion, and pleural thickness in apex. Chest CT scan showed bone destruction of left clavicle head, manubrium and large abscess pocket in pectoralis muscle. In May 1996 he underwent en bloc resection of left upper anterior chest wall including pectoralis major and minor muscle, left clavicle head, manubrium and covering infected skin, then contralateral pectoralis major muscle flap and skin graft was done. Patient shows no evidence of recurrence during follow up.

• Journal of Intelligence and Information Systems
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• v.13 no.1
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• pp.15-27
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• 2007

In Korea, hepatoma is the thirdly frequent cause of death from cancer occupying 17.2% among the whole deaths from cancer and the rate of death from hepatoma comes to about 21's persons per one-hundred thousand ones. This paper proposes an automatic method for the extraction of areas being suspicious as hepatoma from a CT scan and evaluates the availability as an auxiliary tool for the diagnosis of hepatoma. For detecting tumors in the internal of the liver from CT scans, first, an area of the liver is extracted from about $45{\sim}50's$ CT scans obtained by scanning in 2.5-mm intervals starting from the lower part of the chest. In the extraction of an area of the liver, after unconcerned areas outside of the ribs being removed, areas of the internal organs are separated and enlarged by using intensity information of the CT scan. The area of the liver is extracted among separated areas by using information on position and morphology of the liver. Since hepatoma is a hypervascular turner, the area corresponding to hepatoma appears more brightly than the surroundings in contrast-enhancement CT scans, and when hepatoma shows expansile growth, the area has a spherical shape. So, for the extraction of areas of hepatoma, areas being brighter than the surroundings and globe-shaped are selected as candidate ones in an area of the liver, and then, areas appearing at the same position in successive CT scans among the candidates are discriminated as hepatoma. For the performance evaluation of the proposed method, experiment results obtained by applying the proposed method to CT scans were compared with the diagnoses by radiologists. The evaluation results showed that all areas of the liver and liver tumors were extracted exactly and the proposed method has a high availability as an auxiliary diagnosis tools for the discrimination of liver tumors.