• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.911-917
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• 2023

The method of observing nodular changes on the liver surface using clinical ultrasonography is useful for diagnosing cirrhosis. However, the speckle noise that inevitably occurs in ultrasound images makes it difficult to identify changes in the liver surface and echo patterns, which has a negative impact on the diagnosis of cirrhosis. The purpose of this study is to model the median modified Wiener filter (MMWF), which can efficiently reduce noise in cirrhotic ultrasound images, and confirm its applicability. Ultrasound images were acquired using an ACR phantom and an actual cirrhotic patient, and the proposed MMWF algorithm and conventional noise reduction algorithm were applied to each image. Coefficient of variation (COV) and edge rise distance (ERD) were used as quantitative image quality evaluation factors for the acquired ultrasound images. We confirmed that the MMWF algorithm improved both COV and ERD values compared to the conventional noise reduction algorithm in both ACR phantom and real ultrasound images of cirrhotic patients. In conclusion, the proposed MMWF algorithm is expected to contribute to improving the diagnosis rate of cirrhosis patients by reducing the noise level and improving spatial resolution at the same time.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.389-396
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• 2015

The liver fibrosis is a disease we often see in clinical medicine, and the persistence and repeatition of inflammation and necrosis of liver cells continue for several years, and it is proceeded to cirrhosis. So decrease of death rate and prevalence rate by complications of cirrhosis and hepatocellular carcinoma is main task of clinical medicine by protection of chronic liver ailment patients from proceeding to cirrhosis and hepatocellular carcinoma. So this study tried to represent the ultrasonic image, blood test, the relationship with liver stiffness of diffuse liver ailment patients as numbers. This study was performed with patients from whom the image was taken by ultrasonic and 141 people who were treated by fibroscan, the basic data for blood test was obtained from the test results at the time when ultrasonic image and liver fibroscan was performed. The statistical analysis was performed by One-way analysis of variance(ANOVA) to verify difference between groups. The value of liver stiffness was increased in the order of normal, chronic liver disease and cirrhosis. As a results, ALT and Albumin have no statistical difference between object groups, and there are statistical differences in the results of ultrasonic decoding at age, AST, ALP, Bilirubin, PLT, PT, and kPa, and they are statistically meaningful(p<0.005). And the value of liver stiffness of chronic liver ailment was presented only as over 12.5kPa in other study, but it was represented as numbers for quantitative diagnosis by presenting average kPa threshold value according to disease in this study. And by presenting relationship of diagnosed results, it is considered that it could be used as first tool to diagnose chronic liver ailment patients according to their disease.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.433-434
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• 2014

최근 간질환 검사의 비침습적인 방법으로 탄성초음파가 각광받고 있는 추세이다. 그러나 진단결과와 탄성초음파 결과 값에 따른 표준 진단 매뉴얼이 없는 실정이다. 따라서 본 연구에서는 탄성초음파 수치에 따른 간질환의 종류와 B-mode 영상 간의 경향을 알아보고자 하였다. 그리고 환자의 우측 늑간 초음파 B-mode 영상평가 파라미터인 평균, 신호 대 잡음비, 최대신호 대 잡음비, 엔트로피로 분석하고, 동일 부위에 시행한 탄성초음파 수치와의 비교를 통해 경향을 연구하였고, 그 기준을 제시하고자 하였다.

• Journal of Sensor Science and Technology
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• v.8 no.1
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• pp.16-23
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• 1999

When a moving piezoelectric transducer detects an object in water, its receiving sensitivity is attenuated by Doppler effect. In this paper, a method for compensating the effect is suggested by using a newly designed condenser of which capacitance is varied according to the moving speed of the transducer. Using the method, the receiving resonant frequency of the transducer can be changed automatically. As a result, there is good agreement between the results of experiment and those of calculation. It is confirmed that the response sensitivity degradation of transducers due to Doppler effect can be compensated in the range of $1{\sim}10^m/_s$ moving speed.

• The Journal of the Acoustical Society of Korea
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• v.23 no.4E
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• pp.120-124
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• 2004

A new type of high frequency wideband ultrasonic transducer with a separation between a transmitter and a receiver was proposed and its characteristics were simulated using a PSpice model. The piezoelectric ceramic $PbTiO_{3}$ as a transmitter and the piezoelectric copolymer P(VDF- TrFE) as a receiver were used for high sensitivity and wide bandwidth, respectively. The characteristics of the focusing transducer with center frequency of approximately 35MHz fabricated in this study showed very wide bandwidth, which could give an axial spatial resolution better than $30{\mu}m$ in B-mode image for biological tissues.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1057-1065
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• 2023

Non-invasive liver fibrosis diagnosis is crucial for patients with chronic liver diseases. Many patients cannot undergo liver tissue biopsy, so predicting the degree of liver fibrosis early through meaningful methods can reduce complications related to chronic liver diseases, such as liver cell carcinoma and cirrhosis. This study compared and analyzed the quantitative measurement of liver fibrosis using shear wave elastography in conjunction with liver ultrasound findings and their associations with serum biomarkers (p<0.05). The results showed that the shear wave elastography measurement in the normal group was 4.55 ± 0.69 kPa, while the abnormal contrast group with echogenic patterns had a measurement of 8.27 ± 1.83 kPa. The hepatitis B carrier group exhibited higher shear wave elastography measurements, and among serum biomarkers, AST, ALT, GGT, and PT showed statistically significant positive correlations with fibrosis severity according to SWE categories (p<0.05), while ALP and TB did not demonstrate statistically significant differences (p=0.163, p=0.567). Conversely, Albumin and PLT showed significant negative correlations (p<0.05). Clinically, utilizing shear wave elastography measurements through liver ultrasound in the tracking and repeat testing of liver fibrosis in chronic hepatitis B patients without cirrhosis can assist in achieving more objective diagnoses among healthcare providers.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.2 no.1
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• pp.18-23
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• 2009

Purpose: To evaluate the relationship between the real pathology & abnormal finding found by ultrasonography. Without an MRI test being done beforehand, an arthroscopy is done after an ultrasonography to show abnormal lesions during a knee abnormality. Materials and Methods: The subjects were 42 patients out of 49 cases, excluding those with rheumatoid arthritis, septic arthritis and patients suspected with a ligament tear, which were examined by ultrasonography alone before receiving a knee arthroscopy in our hospital from July 2007 to July 2008. In every case, a physical examination, simple X-ray and knee ultrasonography was done. An arthroscopy was performed when there was ultrasonographic abnormal finding. Before the procedure, a MRI test was not performed and when abnormal findings were found by an arthroscopy, an appropriate surgery was done. Results: During the ultrasonographic examination, there were various sized effusions in the suprapatellar pouch. Also, in addition there were eleven cases of medial meniscus abnormalities, sixteen cases of lateral meniscus abnormalities, and two cases of cystic lesions. Throughout the arthroscopic examination, there were 14 cases of medial meniscus abnormalities, 20 cases of lateral meniscus abnormalities, 15 cases of cartilage damages, 9 cases of medial pathologic plica, 2 cases of intra-articular loose bodies, 5 cases of chondromalacia, 2 cases of cyst, and 2 cases of synovitis. When an effusion abnormality was found by the ultrasonography in a suprapatellar pouch, there was a 100% probability of knee pathology. When a medial meniscus abnormality was found with an ultrasonography, there was a 90.9% probability of a real pathology. When a lateral meniscus abnormality was found there was 81.2% probability of a real pathology. Ultrasonography was 100% accurate when it came to cystic lesions. Conclusion: Knee ultrasonography performed before an arthroscopy seems to be a very useful examination method when suspecting intra-articular lesions.

• Journal of Chest Surgery
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• v.43 no.4
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• pp.399-403
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• 2010

Background: Video-Assisted Thoracic Surgery can be performed with the lung collapsed. During the procedure, pleural adhesion may result in lung injury, bleeding, and thoracotomy conversion. Identifying the presence of pleural adhesion before surgery can make it easy to plan trocar introduction and perform the procedure. Material and Method: Between June 2009 and November 2009, we performed ultrasound in 24 patients to detect pleural adhesion before surgery and compared the results with the operative findings. We primarily examined the lateral chest, where the trocar would be inserted, and, occasionally, the anterior or posterior chest. Result: Patient diseases were: 6 hyperhidroses, 8 interstitial lung diseases, 5 lung cancers, 2 mediastinal tumors, 1 peripheral pulmonary embolism, 1 metastatic lung cancer, and 1 sarcoidosis. Of the 22 patients who did not have pleural adhesions on ultrasound, four revealed mild adhesions not related to the trocar insertion sites. However, ultrasound showed pleural adhesions in two patients, consistent with the operative findings. There was no air leak or thoracotomy conversion related with trocar insertion. Conclusion: Ultrasound requires only a few minutes to detect the presence of the pleural adhesion and was very useful in identifying the pleural adhesion before VATS.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.310-314
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• 2013

A 12-year-old, female mixed breed dog presented with a vaginal mass protruding outside the vulva. The patient was non-gravid, with normal defecation and urination. Serum chemistry revealed azotemia and increased alkaline phosphatase. Hematology findings were normal. Blood electrolytes showed mild hypernatremia. Ultrasonography demonstrated severely enlarged uterine horns, a uterine body with anechoic to hypoechoic fluids, and a focal hypoechoic area within the mass of the right uterine tube. On computed tomography, metastasis was not confirmed. Other computed tomography findings suggested a right ovarian cyst, an enlarged, fluid-filled uterus, and an enlarged vagina with a mass. Ovariohysterectomy, episiotomy, and vaginectomy were performed. The case was diagnosed as uterine tube adenocarcinoma, vaginal fibroma, and pyometra. This case is the first reported concurrent occurrence in dogs.

• Journal of the Korean Society for Nondestructive Testing
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• v.22 no.4
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• pp.354-360
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• 2002

The piezoelectric composites had many advantages in comparison with conventional piezoelectric ceramics and piezopolymers for ultrasonic transducers used in NDT and in medical ultrasionic imaging. The electromechanical coupling coefficient should be high and the acoustic impedance should be low in these applications. However, the cross-coupling with spurious oscillations caused by laterally running plate waves exhibited complex motions in the surface of piezoelectric composites with coarse lateral spatial scale. The thickness mode electromechanical coupling coefficient of 1-3type of piezoelectric compoistes were 0.36 to 0.64, and the acoustic impedance of them were 9.8 to 22.7 MRayl. The lateral resonance frequency of 1-3 type piezoelectric composites shifted to high frequency region with decreasing lateral spatial scale.