• 대한의용생체공학회:의공학회지
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• 제37권4호
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• pp.140-146
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• 2016

The ultrasound imaging in medical diagnosis has become a popular modality because of its safe, noninvasive, portable, relatively inexpensive, and provides a real-time image formation. However, usefulness of ultrasound imaging is at times limited due to the presence of signal-dependent noise like as speckle. Therefore, noise reduction is very important, as various types of noise generated limits the effectiveness of medical image diagnosis. This paper introduces a speckle noise reduce algorithm using total variation denoising (TVD) in Laplacian pyramid. With this method, speckle is removed by TVD of bandpass ultrasound images in Laplacian pyramid domain. For TVD in each pyramid layer, a ${\lambda}$ is selected by trial-and-error method. The visual comparison of despeckled 'in vivo' ultrasound images from pancreas shows that the proposed method could effectively preserve edges and detailed structures while thoroughly suppressing speckle. For a Simulated B-mode image, contrast-to-noise-ratio (CNR) and signal-to-noise-ratio (SNR) were obtained like 4.65 dB and 14.11 dB, respectively. The results show that the proposed method can conduct better than some of the existing methods in terms of the CNR and the SNR.

• Clinical Pain
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• 제20권2호
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• pp.74-85
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• 2021

Ultrasound (US) can depict of various anatomical structures, such as muscles, tendons, ligaments, nerve roots, and vessels, around the neck. The usage of US around the neck is increasing due to its quick and easy application for guided injection for nerves, tendons, and joints. This article elaborates the degenerative diseases causing neck pain, sonoanatomy, and the use of US for diagnosis and intervention; for example, small nerves around the neck, cervical root, stellate ganglion, medial branches, greater occipital nerve (GON), and third occipital nerve (TON). The aim of this review article is to lead readers to understand the anatomy around the neck and structural relations, and to get to know about several US-guided intervention of the neck.

• 한국의학물리학회지:의학물리
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• 제18권3호
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• pp.172-178
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• 2007

가로축 방식이 아닌 세로축 방식으로 초음파를 송수신하여 골밀도 측정을 하는 장치를 개발하였다. 반사된 초음파의 시간 차이를 이용하는 speed of sound (SOS) 방식은 주파수 차이를 비교하는 broadband ultrasound attenuation (BUA) 방식에 비하여 더욱 정확한 결과를 얻을 수 있다. 측정부위의 경우 엄지는 초음파 수신율이 좋으나 피부 두께의 변위가 많은 단점을 고려하여 중지를 채택하여 정확성을 높였다. SOS 방식만을 사용하여 측정한 결과 기존의 dual-energy x-ray absorptiometry (DEXA) 방식과 비교하여 거의 동일한 정확도를 얻을 수 있었다.

• Clinics in Shoulder and Elbow
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• 제23권2호
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• pp.80-85
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• 2020

Background: Atelocollagen has been studied for restoration of rotator cuff tendon. In this study, we attempted to evaluate the clinical outcome of ultrasound-guided atelocollagen injection in an outpatient clinic for patients with partial rotator cuff tear. Methods: We recruited 42 outpatients who visited our hospital from May 2019 to September 2019. Atelocollagen injection was performed in patients with partial rotator cuff tear diagnosed by magnetic resonance imaging and ultrasound. American Shoulder and Elbow Surgeons (ASES), Constant, Korean Shoulder Score (KSS) and Simple Shoulder Test (SST) scores, and range of motion were assessed before injection and after 2 months. Statistically, we analyzed the clinical results using the Wilcoxon signed-rank test. Results: Finally, 15 patients were enrolled for analysis. There was no significant difference between pre- and post-injection in terms of range of motion, ASES (57.0 vs. 60.4), Constant (56.4 vs. 58.9), KSS (64.6 vs. 68.5), and pain-visual analog scale (4.2 vs. 3.7), except function-visual analog scale (F-VAS; 6.3 vs. 7.1) and SST (6.6 vs. 6.9). A significant difference was found in SST (P=0.046) and F-VAS (P=0.009). According to the ultrasound results at 2 months, we found hyperechoic materials in three of seven patients. The most common complication of atelocollagen injection was post-injection pain (53%, 8/15). Conclusions: Ultrasound-guided atelocollagen injection for partial rotator cuff tear showed no significant change in terms of clinical outcomes, except for F-vas and SST score. Tendon regeneration was not clear due to the remnants of atelocollagen present at 2-month follow-up ultrasound. There seems to be alarming post-injection pain for 2 to 3 days in the patients who received atelocollagen injection in an outpatient clinic.

• Journal of Animal Science and Technology
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• 제65권2호
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• pp.365-376
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• 2023

Pig breeding management directly contributes to the profitability of pig farms, and pregnancy diagnosis is an important factor in breeding management. Therefore, the need to diagnose pregnancy in sows is emphasized, and various studies have been conducted in this area. We propose a computer-aided diagnosis system to assist livestock farmers to diagnose sow pregnancy through ultrasound. Methods for diagnosing pregnancy in sows through ultrasound include the Doppler method, which measures the heart rate and pulse status, and the echo method, which diagnoses by amplitude depth technique. We propose a method that uses deep learning algorithms on ultrasonography, which is part of the echo method. As deep learning-based classification algorithms, Inception-v4, Xception, and EfficientNetV2 were used and compared to find the optimal algorithm for pregnancy diagnosis in sows. Gaussian and speckle noises were added to the ultrasound images according to the characteristics of the ultrasonography, which is easily affected by noise from the surrounding environments. Both the original and noise added ultrasound images of sows were tested together to determine the suitability of the proposed method on farms. The pregnancy diagnosis performance on the original ultrasound images achieved 0.99 in accuracy in the highest case and on the ultrasound images with noises, the performance achieved 0.98 in accuracy. The diagnosis performance achieved 0.96 in accuracy even when the intensity of noise was strong, proving its robustness against noise.

• Clinical Pain
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• 제20권2호
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• pp.86-92
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• 2021

Ultrasound imaging in clinical practice is one of the widely used diagnostic methods because there is no radiation risk, more cost- effective compared to MRI or CT, and possible to perform an intervention through fast real-time imaging. In order to increase the diagnostic value, the studies of contrast-enhanced ultrasound (CEUS) using an ultrasound contrast agent have been actively conducted since about 50 years ago and are being used clinically in vascularity and microcirculation of internal organs. Although ultrasound is actively used for the diagnosis and treatment of various diseases in musculoskeletal disorders, there are some limitations in diagnosing mild or small lesions, inflammatory reactions, or abnormalities at the molecular level. In this review, the principles, types, and research, and clinical applications of ultrasound contrast agents have been summarized and introduced. If we understand the characteristics of the ultrasound contrast agents and anatomical knowledge, as well as molecular changes, the ultrasound contrast agents are widely applied in musculoskeletal disorders and have tremendous potential for diagnosis and treatment.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2929-2932
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• 2014

Purpose: To evaluate the diagnostic performances of risk of malignancy index (RMI), CA-125 and ultrasound score in differentiating between benign and borderline or malignant ovarian tumors and find the best diagnostic test for referral of suspected malignant ovarian cases to gynaecologic oncologists. Materials and Methods: This prospective study covered 467 women with pelvic tumors scheduled for surgery at our hospital between July 2011 and July 2013. The RMI was obtained from ultrasound score, CA125 and menopausal status. The diagnostic values of each parameter and the RMI were determined and compared using Statistical Packages for Social Sciences Version 14.0.1. Results: In our study, 61% of ovarian tumors were malignant in the post-menopausal age group. RMI with a cut-off 150 had sensitivity of 84% and specificity of 97% in detecting ovarian cancer. CA-125>30 had a sensitivity of 84% and a specificity of 83%. An ultrasound score more than 2 had a sensitivity of 96% and specificity of 81%. RMI had the least false malignant cases thus avoiding unnecessary laparotomies. Ultrasound when used individually had the best sensitivity but poor specificity. Conclusions: Our study has demonstrated the RMI to be an easy, simple and applicable method in the primary evaluation of patients with pelvic masses. It can be used to refer suspected malignant patients to be operated by a gynaecologic oncologist. Other models of preoperative evaluation should be developed to improve the detection of early stage invasive, borderline and non-epithelial ovarian cancers.

• Journal of Korean Medical Science
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• 제33권44호
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• pp.279.1-279.16
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• 2018

Magnetic resonance-guided focused ultrasound (MRgFUS) is a new emerging neurosurgical procedure applied in a wide range of clinical fields. It can generate high-intensity energy at the focal zone in deep body areas without requiring incision of soft tissues. Although the effectiveness of the focused ultrasound technique had not been recognized because of the skull being a main barrier in the transmission of acoustic energy, the development of hemispheric distribution of ultrasound transducer phased arrays has solved this issue and enabled the performance of true transcranial procedures. Advanced imaging technologies such as magnetic resonance thermometry could enhance the safety of MRgFUS. The current clinical applications of MRgFUS in neurosurgery involve stereotactic ablative treatments for patients with essential tremor, Parkinson's disease, obsessive-compulsive disorder, major depressive disorder, or neuropathic pain. Other potential treatment candidates being examined in ongoing clinical trials include brain tumors, Alzheimer's disease, and epilepsy, based on MRgFUS abilities of thermal ablation and opening the blood-brain barrier. With the development of ultrasound technology to overcome the limitations, MRgFUS is gradually expanding the therapeutic field for intractable neurological disorders and serving as a trail for a promising future in noninvasive and safe neurosurgical care.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 춘계학술대회
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• pp.470-473
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• 2021

본 연구에서는 인공 관절치환술 시 삽입되는 라이너의 잔존 두께 측정과 비구컵과의 결합 상태를 판별 할 수 있는 생체 삽입형 보철물 두께 측정 시스템 개발을 위한 생체 삽입형 초음파 변환자의 개발, 잔존 두께측정 알고리즘 및 최적화된 초음파 운용 방법에 대한 연구를 진행했다. 세부적으로, 비슷한 민감도와 대역폭을 갖는 8MHz 와 20MHz의 중심주파수를 갖는 초음파 변환자를 제작하여 상용 폴리에틸렌 재질의 인공 고관절 라이너의 다양한 두께를 측정함으로써 신호대잡음비와 축방향 해상도 비교 분석을 진행하여 체내 초음파 운용 방식 최적화 연구를 진행하였다.

• The Korean Journal of Pain
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• 제29권1호
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• pp.29-33
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• 2016

Background: The purpose of this study was to evaluate the effect of dexamethasone or dexmedetomidine added to ropivacaine on the onset and duration of ultrasound-guided axillary brachial plexus blocks (BPB). Methods: Fifty-one ASA physical status I-II patients with elective forearm and hand surgery under axillary brachial plexus blocks were randomly allocated to receive 20 ml of 0.5% ropivacaine with 2 ml of isotonic saline (C group, n = 17), 20 ml of 0.5% ropivacaine with 2 ml (10 mg) of dexamethasone (D group, n = 17) or 20 ml of 0.5% ropivacaine with 2 ml ($100{\mu}g$) of dexmedetomidine (DM group, n = 17). A nerve stimulation technique with ultrasound was used in all patients. The onset time and duration of sensory blocks were assessed. Results: The duration of the sensory block was extended in group D and group DX compared with group C (P < 0.05), but there was no significant difference between group D and group DX. However, there were no significant differences in onset time in all three groups. Conclusions: Dexamethasone 10 mg and dexmedetomidine $100{\mu}g$ were equally effective in extending the duration of ropivacaine in ultrasound-guided axillary BPB with nerve stimulation. However, neither drug has significantly effects the onset time.