• Journal of the Korean Society of Radiology
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• v.12 no.3
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• pp.403-407
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• 2018

Currently, the highest cancer death rate in Korea is lung cancer, which is a typical cancer that is difficult to detect early. Low-dose chest CT is being used for early detection, which has a greater lung cancer diagnosis rate of about three times than regular chest x-ray images. However, low-dose chest CT not only significantly reduces image resolution but also has a weak signal and is sensitive to noise. Also, air filled lungs are low-density organs and the presence of noise can significantly affect early diagnosis of cancer. This study used Visual C++ to set a circle inside a large circle with a density of 2.0, with a density of 1.0, which is the density of water, in which five small circle of mathematics have different densities. Gaussian noise was generated by 1%, 2%, 3%, and 4% respectively to determine the effect of noise on the mean value, the standard deviation value, and the relative noise ratio(SNR). In areas where the density difference between the large and small circles was greatest in the event of 1 % noise, the SNR in the area with the greatest variation in noise was 4.669, and in areas with the lowest density difference, the SNR was 1.183. In addition, the SNR values can be seen to be high if the same results are obtained for both positive and negative densities. Quality was also clearly visible when the density difference was large, and if the noise level was increased, the SNR was reduced to significantly affect the noise. Low-density organs or organs in areas of similar density to cancers, will have significant noise effects, and the effects of density differences on the probability of noise will affect diagnosis.

• The Journal of Korean Society for Radiation Therapy
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• v.28 no.2
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• pp.87-99
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• 2016

Purpose : This study will evaluate the clinical utility by applying clinical schematic that uses monoenergy or dual energy as according to the location of tumors to the stereotactic radiotherapy to compare the change in actual dose given to the real tumor and the dose that locates adjacent to the tumor. Materials and Methods : CT images from a total of 10 patients were obtained and the clinical planning were planned based on the volumetric modulated arc therapy on monoenergy and dual energy. To analyze the change factor in the tumor, Comformity Index(CI) and Homogeneity Index(HI) and maximum dose quantity were each calculated and comparing the dose distribution on normal tissues, $V_{10}$ and $V_5$, first ~ fourth ribs closest to the tumor ($1^{st}{\sim}4^{th}$ Rib), Spinal Cord, Esophagus and Trachea were selected. Also, in order to confirm the accuracy on which the planned dose distribution is really measured, the 2-dimensional ion chamber array was used to measure the dose distribution. Results : As of the tumor factor, CI and HI showed a number close to 1 when the two energies were used. As of the maximum dose, the front chest wall showed 2% and the dorsal tumor showed equivalent value. As of normal tissue, the front chest wall tumors were reduced by 4%, 5% when both energies were used in the adjacent rib and as of trachea, reduced by 11%, 17%. As of the dose in the lung, as of $V_{10}$, it reduced by 1.5%, $V_5$ by 1%. As of the rear chest wall, when both energies were used, the ribs adjacent to the tumors showed 6%, 1%, 4%, 12% reduction, and in the lung dose distribution, $V_{10}$ reduced by 3%, and $V_5$ reduced by 3.1%. The dose measurement in all energies were in accordance to the results of Gamma Index 3mm/3%. Conclusion : It is considered that rather than using monoenergy, utilizing double energy in the clinical setting can be more effectively applied to the superficial tumors.

• Journal of Trauma and Injury
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• v.18 no.2
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• pp.119-126
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• 2005

Background: Blunt thoracic trauma in children has a high morbidity and mortality. In this study, we assessed the significance of the injury pattern, mechanism and initial status in emergency department on severity and prognosis in pediatric blunt thoracic trauma patients. Method: We retrospectively reviewed medical records and chest X-ray and CT images of 111 pediatric blunt thoracic trauma patients from October 2000 to June 2005. Data recorded age, gender, season, injury mechanism, injury pattern, associated injury, length of hospital stay and cause of death. Result: Of all 111 patients, 68 patients were injured by motor vehicle accidents, 30 were falls, 5 were motorcycle accidents, 3 were sports accidents and 5 were miscellaneous. In thoracic trauma, single injury of lung contusion were 35 patients and 32 patients had multiple thoracic injuries. Hospital stay in school age group were longer than preschool age group. The causes of death were brain injury in 9, respiratory distress in 4, and hypovolemic shock in 2 patients. Emergently transfused and mechanically ventilated patients had higher mortality rates than other patients. Patients required emergency operation and patients with multiple thoracic injuries had higher mortality rates. Conclusion: In this study, patients with combined injury, emergency transfusion, mechanical ventilation, emergency operation, multiple injuries in chest X-ray had higher mortality rates. Therefore in these pediatric blunt thoracic trauma patients, accurate initial diagnosis and proper management is required.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.361-365
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• 2006

A spayed female, 5-year-old, weighing 2.7 kg, domestic short hair cat was referred to Veterinary Medical Teaching Hospital, Seoul National University. The clinical signs of this patient were weight loss, sneezing, respiratory distress, nasal discharge, epistaxis, ocular discharge, left exophthalmos, and left facial edema and deformity. The laboratory tests represented mild leukocytosis. On the skull radiographs, soft tissue density filled nasal cavity with loss of turbinate detail was found. Destructive and lytic changes of the left nasal bone with soft tissue swelling were identified. On the thorax radiographs, there were a tracheobronchial lymph node swelling and a soft tissue round mass in the left caudal lung field. On computed tomographic scan images, asymmetrical destruction of turbinate and nasal septum and increased soft tissue opacity in the nasal cavity were identified. Destruction of the lateral maxillary bone, invasion to the left retrobulbar region, and craniodorsal deviation of the left eye were seen. Also, there was lysis of hard palate and cribriform plate. Invasion to the brain was found. The patient was diagnosed as nasal lymphoma by cytology and histopathology.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.22 no.1
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• pp.56-59
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• 2011

Inflammatory pseudotumor is characterized by the presence of a mass that may mimic malignancy and is composed of spindle cells mixed with variable amounts of extracellular collagen, lymphocytes, and plasma cells It is benign tumor commonly involves lung and orbit and rarely that occurs in the head and neck The cause and pathogenesis of inflammatory pseudotumor still remain controversial. Some bacterial infection or chronic irritation may have prompted some speculation that an initially reactive process can change into an overt neoplastic disease. It tends to affect children and young adults than old ages. We present a case of inflammatory pseudotumor involving the tongue base, in a 73-year-old patient with repeated oral bleeding that aggravated over a few days. Clinical examination showed angiomatous polyp like findings in oropharynx that easy bleeding tendency. CT images showed well defined soft tissue mass with focal enhancement. After surgery, tumor was finally diagnosed inflammatory pseudotumor by histopathologic examinations showed plasma cells and inflammatory cells in variable fibrotic tissues.

• Journal of the Korean Society of Radiology
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• v.82 no.3
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• pp.749-755
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• 2021

Congenital defects of the pericardium, which are generally asymptomatic, are rare disorders characterized by complete or partial absence of the pericardium. Here, we report a rare case of a 19-year-old male who was incidentally diagnosed with congenital absence of the left pericardium during examination for symptoms of pneumothorax. Chest radiography and CT revealed a collapsed left lung without any evidence of trauma, no unusual findings of free air spaces along the right side of the ascending aorta, heart shifted toward the left side of the thorax, and a shallow chest. Subsequent thoracoscopy confirmed the absence of the left pericardium and displacement of the heart toward the left thoracic cavity. We further discuss the correlation between radiologic images and surgical findings of a congenital pericardial defect associated with spontaneous pneumothorax.

• Radiation Oncology Journal
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• v.21 no.1
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• pp.82-93
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• 2003

Purpose : To reduce the Irradiation dose to the lungs and heart in the case of chest wail irradiation using an oppositional electron beam, we used an Individualized custom bolus, which was precisely designed to compensate for the differences In chest wall thickness. The benefits were evaluated by comparing the normal tissue complication probablilties (NTCPS) and dose statistics both with and without boluses. Materials and Methods : Boluses were made, and their effects evaluated in ten patients treated using the reverse hockey-stick technique. The electron beam energy was determined so as to administer 80% of the irradiation prescription dose to the deepest lung-chest wall border, which was usually located at the internal mammary lymph node chain. An individualized custom bolus was prepared to compensate for a chest wall thinner than the prescription depth by meticulously measuring the chest wall thickness at 1 emf intervals on the planning CT Images. A second planning CT was obtained overlying the individuailzed custom bolus for each patient's chest wall. 3-D treatment planning was peformed using ADAC-Pinnacle$^{3}$ for all patients with and without bolus. NTCPS based on 'the Lyman-Kutcher' model were analyzed and the mean, maximum, minimum doses, V$_{50}$ and V$_{95}$ for 4he heari and lungs were computed. Results .The average NTCPS in the ipsliateral lung showed a statistically significant reduction (p<0.01), from 80.2${\pm}$3.43% to 47.7${\pm}$4.61%, with the use of the individualized custom boluses. The mean lung irradiation dose to the ipsilateral iung was also significantly reduced by about 430 cGy, Trom 2757 cGy to 2,327 cGy (p<0.01). The V$_{50}$ and V$_{95}$ in the ipsilateral lung markedly decreased from the averages of 54.5 and 17.4% to 45.3 and 11.0%, respectively. The V$_{50}$ and V$_{95}$ In the heart also decreased from the averages of 16.8 and 6.1% to 9.8% and 2.2%, respectively. The NTCP In the contralateral lung and the heart were 0%, even for the cases with no bolus because of the small effective mean radiation volume values of 4.4 and 7.1%, respectively Conclusion : The use of an Individualized custom bolus in the radiotherapy of postrnastectorny chest wall reduced the NTCP of the ipsilateral lung by about 24.5 to 40.5%, which can improve the complication free cure probability of breast cancer patients.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.27-35
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• 2017

Purpose: On the left side, breast cancer patients have more side effects than those on the right side because of unnecessary doses in normal organs such as heart and lung. DIBH is performed to reduce this. To evaluate the dose of peripheral organs in the left breast cancer including supraclavicular lymph nodes and internal mammary lymph nodes according to the treatment planning method of Conventional Radiation Therapy, Intensity Modulated Radiation Therapy and Volumetric Modulated Arc Therapy. Materials and Methods: We performed CT-simulation using free breathing and deep inspiration breath-hold technique for 8 patients including left supraclavicular lymph nodes and internal mammary lymph nodes. Based on the acquired CT images, the contour of the body is drawn and the convention is performed so that $95%{\leftarrow}PTV$, $Dmax{\leftarrow}110%$. Conventional Radiation Therapy used a one portal technique on the supraclavicular lymph node and used a field in field technique tangential beam on the breast. Intensity Modulated Radiation Therapy was composed of 7 static fields. Volumetric Modulated Arc Therapy was planned using 2 ARC with a turning radius of $290^{\circ}$ to $179^{\circ}$. The peripheral normal organs dose was analyzed by referring to the dose volume of Eclipse. Results: By applying the deep inspiration breath-hold technique, the mean interval between the heart and chest wall increased $1.6{\pm}0.6cm$. The mean dose of lung was $19.2{\pm}1.0Gy$, which was the smallest value in Intensity Modulated Radiation Therapy. The V30 (%) of the heart was $2.0{\pm}1.9$, which was the smallest value in Intensity Modulated Radiation Therapy. In the left anterior descending coronary artery, the dose was $25.4{\pm}5.4Gy$, which was the smallest in Intensity Modulated Radiation Therapy. The maximum dose value of the Right breast was $29.7{\pm}4.3Gy$ at Intensity Modulated Radiation Therapy. Conclusion: When comparing the values of surrounding normal organs, Intensity Modulated Radiation Therapy and Volumetric Modulated Arc Therapy were applicable values for treatment. Among them, Intensity Modulated Radiation Therapy is considered to be a suitable treatment planning method.

• Advances in nano research
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• v.13 no.6
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• pp.575-585
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• 2022

Due to its biofilm formation and colonization of the osteocyte-lacuno canalicular network (OLCN), Staphylococcus aureus (S.aureus) implant-associated bone infection (SIABI) is difficult to cure thoroughly, and may occur recurrently subsequently after a long period dormant. It is essential to explore an alternative therapeutic strategy that can eradicate the pathogens in the infected foci. To address this, the polymethylmethacrylate (PMMA) bone cement and Fe3O4 nanoparticles compound cylinder were developed as implants based on their size and mechanical properties for the alternative magnetic field (AMF) induced thermal ablation, The PMMA mixed with optimized 2% Fe₃O₄ nanoparticles showed an excellent antibacterial efficacy in vitro. It was evaluated by the CFU, CT scan and histopathological staining on a rabbit 1-stage transtibial screw model. The results showed that on week 7, the CFU of infected soft tissue and implants, and the white blood cells (WBCs) of the PMMA+2% Fe₃O₄+AMF group decreased significantly from their controls (p<0.05). PMMA+2% Fe₃O₄+AMF group did not observe bone resorption, periosteal reaction, and infectious reactive bone formation by CT images. Further histopathological H&E and Gram Staining confirmed there was no obvious inflammatory cell infiltration, neither pathogens residue nor noticeably burn damage around the infected screw channel in the PMMA+2% Fe₃O₄+AMF group. Further investigation of nanoparticle distributions in bone marrow medullary and vital organs of heart, liver, spleen, lung, and kidney. There were no significantly extra Fe₃O₄ nanoparticles were observed in the medullary cavity and all vital organs either. In the current study, PMMA+2% Fe₃O₄+AMF shows promising therapeutic potential for SIABI by providing excellent mechanical support, and promising efficacy of eradicating the residual pathogenic bacteria in bone infected lesions.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.86-89
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• 2002

The purpose is to develop a system to reduce the organ movement from the respiration during the 3DCRT or IMRT. This research reports the experience of utilizing personally developed system for mobile tumors. The patients clinical database was structured for 10 mobile tumors and patient setup error measurement and immobilization device effects were investigated. The RMRD system is composed of the respiratory motion reduction device utilized in prone position and abdominal strip device(ASD) utilized in the supine position, and the analysis program, which enables the analysis on patients setup reproducibility. Dose to normal tissue between patients with RMRDs and without RMRDs was analyzed by comparing the normal tissue volume, field margins and dose volume histogram(DVH) using fluoroscopy and CT images. And, reproducibility of patients setup verify by utilization of digital images. When patients breathed freely, average movement of diaphragm was 1.2 cm in prone position in contrast to 1.6 cm in supine position. In prone position, difference in diaphragm movement with and without RMRDs was 0.5 cm and 1.2 cm, respectively, showing that PTV margins could be reduced to as much as 0.7 cm. With RMRDs, volume of the irradiated normal tissue (lung, liver) reduced up to 20 % in DVH analysis. Also by obtaining the digital image, reproducibility of patients setup verify by visualization using the real-time image acquisition, leading to practical utilization of our software. Internal organ motion due to breathing can be reduced using RMRDs, which is simple and easy to use in clinical setting. It can reduce the organ motion-related PTV margin, thereby decrease volume of the irradiated normal tissue.