• Journal of the Korean Society of Radiology
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• v.81 no.2
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• pp.448-452
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• 2020

Clear cell hidradenoma is a tumor that originates from a sweat gland and typically involves the dermis and subcutaneous tissue. Malignant clear cell hidradenoma is very rare, and surgical excision is usually performed without imaging. There are few reports of the ultrasonographic findings of malignant clear cell hidradenomas. Herein, we present the ultrasonographic characteristics of a malignant clear cell hidradenoma.

• Radiation Oncology Journal
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• v.26 no.4
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• pp.237-246
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• 2008

Purpose: Three-dimensional conformal radiation therapy (3DCRT) and intensity-modulated radiation therapy (IMRT) were found to reduce the incidence of acute and late rectal toxicity compared with conventional radiation therapy (RT), although acute and late urinary toxicities were not reduced significantly. Acute urinary toxicity, even at a low-grade, not only has an impact on a patient's quality of life, but also can be used as a predictor for chronic urinary toxicity. With bladder filling, part of the bladder moves away from the radiation field, resulting in a small irradiated bladder volume; hence, urinary toxicity can be decreased. The purpose of this study is to evaluate the impact of bladder volume on acute urinary toxicity during RT in patients with prostate cancer. Materials and Methods: Forty two patients diagnosed with prostate cancer were treated by 3DCRT and of these, 21 patients made up a control group treated without any instruction to control the bladder volume. The remaining 21 patients in the experimental group were treated with a full bladder after drinking 450 mL of water an hour before treatment. We measured the bladder volume by CT and ultrasound at simulation to validate the accuracy of ultrasound. During the treatment period, we measured bladder volume weekly by ultrasound, for the experimental group, to evaluate the variation of the bladder volume. Results: A significant correlation between the bladder volume measured by CT and ultrasound was observed. The bladder volume in the experimental group varied with each patient despite drinking the same amount of water. Although weekly variations of the bladder volume were very high, larger initial CT volumes were associated with larger mean weekly bladder volumes. The mean bladder volume was $299{\pm}155\;mL$ in the experimental group, as opposed to $187{\pm}155\;mL$ in the control group. Patients in experimental group experienced less acute urinary toxicities than in control group, but the difference was not statistically significant. A trend of reduced toxicity was observed with the increase of CT bladder volume. In patients with bladder volumes greater than 150 mL at simulation, toxicity rates of all grades were significantly lower than in patients with bladder volume less than 150 mL. Also, patients with a mean bladder volume larger than 100 mL during treatment showed a slightly reduced Grade 1 urinary toxicity rate compared to patients with a mean bladder volume smaller than 100 mL. Conclusion: Despite the large variability in bladder volume during the treatment period, treating patients with a full bladder reduced acute urinary toxicities in patients with prostate cancer. We recommend that patients with prostate cancer undergo treatment with a full bladder.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.2
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• pp.70-77
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• 2019

Breast ultrasound readings are very important to diagnose early breast cancer. In Ultrasonic inspection, it shows a significant difference in image quality depending on the ultrasonic equipment, and there is a large difference in diagnosis depending on the experience and skill of the inspector. Therefore, objective criteria are needed for accurate diagnosis and treatment. In this study, we analyzed texture characteristics by applying GLCM (Gray Level Co-occurrence Matrix) algorithm and extracted characteristic parameters and diagnosed breast cancer using neural network classifier. Breast ultrasound images were classified into normal, benign and malignant tumors and six texture parameters were extracted. Fourteen cases of normal, malignant and benign tumor diagnosed by mammography were studied by using the extracted six parameters and learning by multi - layer perceptron neural network back propagation learning method. As a result of classification using 51 normal images, 62 benign tumor images, and 74 malignant tumor images of the learned model, the classification rate was 95.2%.

• Journal of Biomedical Engineering Research
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• v.25 no.3
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• pp.201-206
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• 2004

The bone formation and re-formation are regulated by two factors that are the synthesis of bone matrix by osteoblast and reabsorption by osteoclast. Recently, there are many studies about regeneration and healing of bone tissue by activation of osteoblast. In general, it is known that the activation of osteoblast is influenced by not only biological stimulus but physical stimulus. In this study, we verified that ostoeblast activation was influenced by low intensity ultrasound. Various ultrasonic properties were used to find out the most appropriate condition on cell activation. From this study, we could confirm that 0.3W/$\textrm{cm}^2$ intensity of ultrasound was the most appropriate to tell activation over whole duty cycles and the increasing rate of tell was the highest at 50％ duty cycle. Thus, it is expected that optimal ultrasonic characteristics on regeneration of bone matrix may be applied to fracture and osteoporosis healing.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.655-656
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• 2008

• Proceedings of the Korean Information Science Society Conference
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• 2011.06b
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• pp.290-293
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• 2011

치아 스케일링은 치아에 단단하게 결착된 치석을 제거하는 치과 시술로서 치아 우식 및 잇몸염증을 예방하는 중요한 시술이다. 특히 요즘에는 치료시간의 단축을 통한 효율성 증대의 목적으로 전기적 에너지를 미세한 진동에너지로 바꾸는 원리를 활용한 초음파 스케일링 기법이 많이 행해지고 있다. 하지만 치아 및 치석 확보에 따른 어려움으로 인해 스케일링 시술을 충분히 훈련하기란 쉽지 않다. 본 논문에서는 사용자가 가상현실을 통해 시각 및 촉각 피드백을 받으며 초음파 스케일링 시술을 훈련할 수 있는 치아 스케일링 시뮬레이션을 위한 알고리즘을 제안한다. 치아, 치석 및 잇몸의 볼륨모델과 스케이러 팁을 구성하는 각 부문의 관통깊이를 이용한 햅틱 랜더링 기법을 적용하여 스케일러의 모양에 따른 햅틱 피드백을 생성하였다. 그리고 치아의 손상을 줄이기 위해 스케일러의 팁 부문이 치아 표면에 되도록 평형을 이루어야 한다는 점에 입각하여, 치석을 구성하는 복셀들의 치아 디스턴스필드 값 비교를 통해 치석과 치아 사이의 접착면을 추출하고 스케일러의 팁 부분과 충돌하는 추출된 집착면의 각도를 고려한 스케일링 알고리즘을 구현하였다. 또한 수동 스케일링과는 달리 초음파 스케일링은 초음파의 진동에너지에 의해 점진적으로 치아와 치석 사이의 결속력이 감소된다는 점에 착안하여 치아와 치석의 접착면을 구성하는 지점 사이의 거리에 따른 결속력 감쇠 모델을 고안하였다.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1049-1055
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• 2023

The purpose of this study was to investigate the association of twinkling artifacts according to the types of urinary stones in color Doppler ultrasound. For two types of urinary stones with different colors, the degree of occurrence of color Doppler twinkling artifact in water tank was analyzed, and the surface condition and composition of the stones were analyzed. The composition of Calcium and phosphorus were the most frequent components in white and brown stones excluding carbon and oxygen. Twinkling artifacts of color Doppler appear stronger in brown stone. The higher the phosphorus content of the stones, the shorter the twinkling artifact appears, so it is possible to predict the main composition of stones.

• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.861-875
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• 2022

Sonography with a high-frequency transducer is the modality of choice for imaging the scrotum. Most intratesticular lesions are hypoechoic. Differentiation of intratesticular hypoechoic lesions as either malignant or benign is important because the treatment of these lesions vary. In this paper, we review the sonographic features of different types of intratesticular hypoechoic lesions, such as testicular cysts, testicular tumors, testicular inflammatory lesions, segmental testicular infarction, and testicular trauma.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1233-1243
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• 2023

Percutaneous ultrasound-guided biopsy is useful for the pathologic confirmation of variable body lesions to establish diagnostic and therapeutic approaches. However, deep pelvic lesions are a challenge for pathologic diagnoses because of the presence of the bowel, bladder, major vessels, and pelvic bones which make a percutaneous approach difficult and dangerous. In female, the vagina is elastic and near the pelvic internal organs. Therefore, transvaginal ultrasound may serve as an effective and safe guide for the pathologic diagnosis of pelvis lesions. This review aimed to introduce the indications for, and the method of transvaginal ultrasoundguided biopsy, and to describe the reported diagnostic accuracy and safety.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.3 no.2
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• pp.54-58
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• 2010

Purpose: In patients with chronic cervical pain, the facet joint is the source of the majority. Due to the difficulty of identifying the exact location of the joint that causes these symptoms, the possibility of complications and the placebo effect brings clinical application into question. In this study, we assessed the prevalence of patients with chronic cervical pain and report the diagnostic and therapeutic usefulness of ultrasonography - guided facet joint block therapy. Materials and Methods: Patients with nonspecific chronic cervical pain for more than 6 months were selected. Patients with disc herniation, sciatica-related pain were excluded from the study and 160 patients who failed in conservative treatment (physical therapy, chiropractic therapy, medication) were included in the study. Diagnostic Ultrasonography-guided facet joint block was performed with 1% lidocaine, and after two weeks, Bupivacaine 0.25% was used in patients who tested positive for lidocaine. Patients with more than 75% pain reduction during movement after facet joint block were considered positive. Results: Among the 160 patients with chronic cervical pain, 96 patients(60%) had a positive reaction after facet block using lidocaine. Among the 64 patients with a negative reaction to lidocaine, 48 patients(75%) had a positive reaction to bupivacaine. There were 48 false positive patients(50%) who showed a positive reaction to lidocaine but a negative reaction to bupivacaine. The mean VAS of the total 160 patients before blocks was 8.5, after 2 weeks follow up it decreased to 2.7 (p = 0.001) and after 4weeks 3.6 (p = 0.001). The 8 patients as an initial improvement of symptoms are not satisfied with the procedure and the 3 patients had been worsened during observation, were showed pain relief after additional ultrasonography-guided facet joint block at 4th week. Conclusion: A single ultrasonography-guided block to chronic cervical pain patients has relatively low diagnostic value since high false positive rate. The twice facet joint blocks is thought to be a useful method for interventional pain management of patients with chronic cervical pain.