• Journal of Biomedical Engineering Research
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• v.32 no.2
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• pp.158-164
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• 2011

Breast cancer is the most frequently appearing cancer in women, these days. To reduce mortality of breast cancer, periodic check-up is strongly recommended. X-ray mammography is one of powerful diagnostic imaging systems to detect 50~100 um micro-calcification which is the early sign of breast cancer. Although x-ray mammography has very high spatial resolution, it is not easy yet to distinguish cancerous tissue from normal tissues in mammograms and new tissue characterizing methods are required. Recently ultrasound elastography technique has been developed, which uses the phenomenon that cancerous tissue is harder than normal tissues. However its spatial resolution is not enough to detect breast cancer. In order to develop a new elastography system with high resolution we are developing x-ray elasticity imaging technique. It uses the small differences of tissue positions with and without external breast compression and requires an algorithm to detect tissue displacement. In this paper, computer simulation is done for preliminary study of x-ray elasticity imaging. First, 3D x-ray breast phantom for modeling woman's breast is created and its elastic model for FEM (finite element method) is generated. After then, FEM experiment is performed under the compression of the breast phantom. Using the obtained displacement data, 3D x-ray phantom is deformed and the final mammogram under the compression is generated. The simulation result shows the feasibility of x-ray elasticity imaging. We think that this preliminary study is helpful for developing and verifying a new algorithm of x-ray elasticity imaging.

• Physical Therapy Korea
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• v.29 no.2
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• pp.131-139
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• 2022

Background: Shoulder impingement syndrome, a major cause of shoulder pain, involves weakness of the scapular retractor muscles. The major scapular retractor muscles are the middle trapezius and rhomboid major muscles; however, the latter is excluded in most studies. Objects: We aimed to measure the thickness of the middle trapezius and rhomboid major muscles using an ultrasonic diagnostic imaging system while performing four different shoulder retraction exercises and comparing the thicknesses and ratio of the thicknesses of these muscles. Methods: The thickness of the middle trapezius and rhomboid major muscles was measured in 24 healthy adults using ultrasound. Muscle thickness was measured three times in the Reference posture and four times while performing four different exercises that involved scapular retraction. The averages and standard deviations of the measured muscle thicknesses were obtained and compared. The ratio of muscle thickness and rate of changes in muscle thickness between the reference posture and the four exercises were compared. Results: For both, male (n = 10) and female (n = 14), there was a significant difference in the thickness of the middle trapezius muscle between the reference posture and the four exercises (p < 0.05) and in the thickness of the middle trapezius and rhomboid major muscles between male and female (p < 0.05); however, there was no significant difference in the ratio of the thicknesses of these muscles. Although a significant difference in the rate of change in muscle thickness during the four exercises was noted, there was no significant difference in the ratio of change in muscle thickness. Conclusion: This study demonstrates the ratio of the thicknesses of the middle trapezius and rhomboid major muscles and the rate of change in their thickness during exercises involving scapular retraction in healthy people in their 20s-30s.

• Korean Journal of Radiology
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• v.24 no.11
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• pp.1102-1113
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• 2023

Objective: To elucidate the use of radiological studies, including nuclear medicine, and biopsy for the diagnosis and staging of prostate cancer (PCA) in clinical practice and understand the current status of PCA in Asian countries via an international survey. Materials and Methods: The Asian Prostate Imaging Working Group designed a survey questionnaire with four domains focused on prostate magnetic resonance imaging (MRI), other prostate imaging, prostate biopsy, and PCA backgrounds. The questionnaire was sent to 111 members of professional affiliations in Korea, Japan, Singapore, and Taiwan who were representatives of their working hospitals, and their responses were analyzed. Results: This survey had a response rate of 97.3% (108/111). The rates of using 3T scanners, antispasmodic agents, laxative drugs, and prostate imaging-reporting and data system reporting for prostate MRI were 21.6%-78.9%, 22.2%-84.2%, 2.3%-26.3%, and 59.5%-100%, respectively. Respondents reported using the highest b-values of 800-2000 sec/mm² and fields of view of 9-30 cm. The prostate MRI examinations per month ranged from 1 to 600, and they were most commonly indicated for biopsy-naïve patients suspected of PCA in Japan and Singapore and staging of proven PCA in Korea and Taiwan. The most commonly used radiotracers for prostate positron emission tomography are prostate-specific membrane antigen in Singapore and fluorodeoxyglucose in three other countries. The most common timing for prostate MRI was before biopsy (29.9%). Prostate-targeted biopsies were performed in 63.8% of hospitals, usually by MRI-ultrasound fusion approach. The most common presentation was localized PCA in all four countries, and it was usually treated with radical prostatectomy. Conclusion: This survey showed the diverse technical details and the availability of imaging and biopsy in the evaluation of PCA. This suggests the need for an educational program for Asian radiologists to promote standardized evidence-based imaging approaches for the diagnosis and staging of PCA.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.9
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• pp.722-727
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• 2013

Medical treatment for animals is very difficult as the opinions of pets' masters take priority over treatment regardless of the seriousness of pets' disease or the needs of medical treatment. In case that a pet has heart disease, especially, it is difficult to get the direct answer from the pet's master on the decision or confirmation of treatment. For those reasons, it is almost impossible to predict and treat the pet before an emergency like the heart failure or an unexpected death happens. Using stethoscope can be the first diagnosis method to check the heart or any kinds of disease inside the body. High-tech equipments like CT, X-ray or Ultrasound can be used, but they can only be used as a second choice of diagnosis method since it requires professional skills and its high price. That's why stethoscope is still the best diagnostic tool when one makes the first diagnosis. In this study, we give a detailed account of digital diagnosis system in which veterinarians can analyze the sound from stethoscope without bringing it to their ears and make a diagnosis wherever they are. And we suggest a new concept of diagnosis system surrounding, which shows the relativeness of disease through Level Crossing Rate(LCR) and energy level from the stethoscope sound made in this system.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.466-471
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• 2011

Optical coherence tomography(OCT) is an emerging medical diagnostic tool that draws great attention in medical and biological fields. It has a 10-100 times higher spatial resolution than that of the clinical ultrasound but lower imaging depth such as 1-2 mm. In order to image internal organs, OCT needs an endoscopic probe. In this paper, the principle of Fourier-domain optical coherence tomography with high-speed imaging capability was introduced. An OCT endoscope based on MEMS technology was developed. It was attached to the Fourier-domain OCT system to acquire three-dimensional tomographic images of gastrointestinal tract of New Zealand white rabbit. The endoscope had a two-axis scanning mirror that was driven by electrostatic force. The mirror stirred an incident light to sweep two-dimensional plane by scanning. The outer diameter of the endoscope was 6 mm and the mirror diameter was 1.2 mm. A three-dimensional image rendered by 200 two-dimensional tomographs with $200{\times}500$ pixels was displayed within 3.5 seconds. The spatial resolution of the OCT system was 8 ${\mu}m$ in air.

• Korean Journal of Head & Neck Oncology
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• v.16 no.1
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• pp.64-68
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• 2000

Objectives: With the recent advances and increasing use of imaging techniques in examination of the neck, the incidence of incidentally discovered thyroid carcinoma has been increasing. This study was carried out to evaluate the clinicopathologic characteristics of incidental thyroid carcinomas and to find optimal therapeutic strategies for these lesions. Materials & Methods: From Jan. 1988 to Aug. 1998, 1,053 patients were operated on for thyroid cancer, of whom 127(12.1%) had incidentally discovered thyroid cancers which were identified during routine health checkups(n=40), diagnostic procedures for unrelated medical conditions(n=39) and mass screening for thyroid cancer(n=48). The preoperative diagnosis was obtained by ultrasound-guided FNAB and the extent of surgery was determined based on frozen section examinations, as well as prognostic factors and gross findings at the time of surgery. Results: There were 6 men and 121 women with a mean age of 45.9 years. Histopathological diagnosis included papillary carcinomas(n=1l9), follicular carcinomas(n=6), poorly differentiated carcinoma(n=l) and medullary carcinoma(n=1). Thirty patients(23.6%) had multifocallesions. The mean diameter of the tumors was 1.1 cm(0.2-3.4 cm). Capsular invasions were found in 53 patients(41.7%) and nodal metastases in 41(32.3%). The surgical procedures used were: 90 less-than total thyroidectomies and 37 total thyroidectomies with central neck node dissection. Lateral neck dissection was added in 5 patients. According to TNM staging, 79 patients(63.2%) were at stage I, 15(12.0%) at stage II, 31(24.8%) at stage III and 0(0.0%) at stage IV. By AMES scoring system, 102 patients(81.6%) were in the low-risk group and 23(18.4%) in the high-risk group. And by MACIS scoring system, 103(86.6%) of 119 papillary thyroid cancer patients were less than 6. Conclusions: The clinicopathological characteristics of incidentally discovered thyroid carcinomas are similar to ordinary thyroid carcinomas. The treatment of choice should be individualized based on the particular clinical situation encountered, as in ordinary thyroid carcinomas.

• Journal of the Korean Society of Radiology
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• v.13 no.1
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• pp.9-14
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• 2019

This study aimed to investigate the performance of the S-detect method in breast ultrasonography and to determine how to reduce unnecessary biopsy by comparing the results of the S-detect method and biopsy. Thirty patients who had undergone breast ultrasonography between August and October 2018 and were scheduled to undergo biopsy because of the presence of breast nodules were retrospectively analyzed. The McNemar test was performed to determine whether detection of a malignant breast mass significantly differed between the S-detect method and biopsy. The following results were obtained from the analysis of the S-detect method: sensitivity, 90.9%; specificity, 84.21%; validity, 86.66%; positive predictive value, 76.92%; and negative predictive value, 94.11%. Analysis of the degree of agreement between the S-detect method and biopsy revealed a kappa value as high as 0.724 (p < 0.05), exhibiting good agreement between the two methods. The S-detect method in breast ultrasonography is diagnostically valuable in terms of distinguishing between malignant and benign breast masses, and if used properly before breast biopsy, unnecessary biopsy can be reduced.

• Journal of radiological science and technology
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• v.38 no.2
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• pp.127-134
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• 2015

This study was designed to determine the prevalence of gallstones in the last three years and evaluate the associated risk factors in the population who underwent health screening. Although there are many studies reporting the prevalence and risk factors of GB polyp, the results varied among each report. The aims of this study were to evaluate the prevalence rate and risk factors of GB polyp, colon polyp and fatty liver in the population who underwent health screening. The study population consisted of 4,877 visited the health promotion center in Dalseogu, Daegu in Korea from January 2011 to December 2013. Each participant in the study had their biliary system gallbladder examined using ultrasonography. The prevalence of GB polyp was evaluated along with age, gender, metabolic syndrom, body mass index (BMI), Fatty liver, Colon polyp. A showed of total 383 (7.9%) people were found to have GB polyps. The prevalence of sex among 256 (9.8%) patients men and 127 (5.6%) women which showed significantly higher in male than in female subjects(p=0.001). The mean size of the GB polyps 4.92 mm (1.6-17 mm). The sizes of most GB polyps (73.6%) were less than 10 mm in diameter. 122 subjects (31.28%) had multiple GB polyps which 2 or more polyps and 261 subjects (68.2%) had single polyp. Independent risk factors related with GB polyp were male gender (OR 0.551, p<0.001), overweight that BMI above $23kg/m^2$ (OR 0.713, p=0.002) triglyceride (OR 0.571, P<0.001), metabolic syndrome (OR 0.049, p=0.033) and colon polyp (OR 1.409, p=0.002). In spite of the conclusion, the prevalence GB polyp was higher than previous Korea and other country reports. The GB polyp in a healthy population was results as 7.9%. The risk factors of GB polyps were found to be male, being overweight, triglyceride, metabolic syndrome and colon polyp. Not only the subject of a health examination is needed but, a further study of the general public when possible.

• Journal of Veterinary Clinics
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• v.32 no.6
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• pp.486-490
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• 2015

Two-demensional echocardiography is routinely used for evaluation of cardiac function. Visualization of the endocardial border is essential for the assessment of global and regional left ventricular with cardiac disease. SonoVue$^{TM}$ is a microbubble contrast agent that consists of sulfur hexafluoride-filled microbubbles in a phospholipid shell. There were many studies about contrast echocardiographic examination using SonoVue$^{TM}$ contrast agent, and various doses of SonoVue$^{TM}$ were used. To our knowledge, in published veterinary medicine, there was not reported for diagnostic efficient dose of SonoVue$^{TM}$ to evaluate contrast enhanced left ventricular endocardial border delineation (LVEBD). The purpose of this study is to compare the visualization time of LVEBD and find efficient dose of SonoVue$^{TM}$ for using various doses in dogs. Ten healthy Beagles were recruited to the study. Three different doses (0.03 ml/kg, 0.05 ml/kg and 0.1 ml/kg) of SonoVue$^{TM}$ were injected. Endocardial segments were assigned based on previously established methodology, where by the four-chamber views of the LV were divided into 6 segments. In this study, Contrast enhancement of the LVEBD after each injection was evaluated visually at the time point of overall contrast enhancement (Segmental scoring 5+) in the LV by three investigators in a blind manner. Statistical analysis was performed with SPSS version 14.0. All data were analyzed using one-way ANOVA, the multiple comparison Scheffe test. When data for the three offsite readers were combined, mean durations of useful contrast were $3.54({\pm}2.14)$, $6.15({\pm}2.61)$, and $24.39({\pm}11.10)$ seconds for the 0.03 ml/kg, 0.05 ml/kg, and 0.1 ml/kg SonoVue$^{TM}$ doses, respectively. After injection of contrast agent, there were no significant change in side effects such as urticaria, angioedema, hypersensitivity reactions, and digestive system disorders. This study suggests that efficient dose of SonoVue$^{TM}$ contrast agent for improvement of the left ventricle visualization is 0.1 ml/kg. The duration of useful enhancement of LVEBD and the reproducibility were also the highest at the 0.1 ml/kg dosage.