• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.294-299
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• 2007

For efficient and accurate diagnosis of ultrasound images, appropriate time gain compensation(TGC) and dynamic range(DR) control of ultrasound echo signals are important. TGC is used for compensating the attenuation of ultrasound echo signals along the depth, and DR controls the image contrast. In recent ultrasound systems, these two factors are automatically set by a system and/or manually adjusted by an operator to obtain the desired image quality on the screen. In this paper, we propose an algorithm to find the optimized parameter values far TGC and DR automatically. In TGC optimization, we determine the degree of attenuation compensation along the depth by dividing an image into vertical strips and reliably estimating the attenuation characteristic of ultrasound signals. For DR optimization, we define a novel cost function by properly using the characteristics of ultrasound images. We obtain experimental results by applying the proposed algorithm to a real ultrasound(US) imaging system. The results verify that the proposed algorithm automatically sets values of TGC and DR in real-time such that the subjective quality of the enhanced ultrasound images may be sufficiently high for efficient and accurate diagnosis.

• Journal of Biomedical Engineering Research
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• v.26 no.1
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• pp.31-35
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• 2005

A novel synthetic aperture method for real-time three-way dynamic focusing is proposed, which provides lateral beam patterns represented as the product of Fourier transforms of transmit subaperture, receive subaperture, and a synthetic window function. In the proposed method, all array elements are fired individually and for each firing echo signals are recorded from all elements of a receive subaperture moving along an array with the transmit element. The three-way dynamic focusing is then achieved by employing a synthetic aperture algorithm for two-way dynamic focusing and a synthetic focusing method for transmit dynamic focusing. Both theoretical analysis and computer simulation results show that the proposed method produces ultrasound beams with improved lateral resolution at all depths compared to the conventional phased array imaging and synthetic aperture focusing methods.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.6 no.2
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• pp.94-100
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• 2013

Musculoskeletal ultrasound has unique advantages that may be free from exposure to radiation, low price compared to MRI, outpatient procedure that can be easily accessible, and better accuracy combined with physical examination. Dynamic ultrasound performed with stress tests are known to be useful for detecting the hidden lesions in the tendons, ligaments, nerves. Ultrasound in the elbow can be used easily in the outpatient for evaluation of the joint surface and synovial space; diagnosis for tendon diseases such as lateral epicondylitis, medial epicondylitis and morbidity of peripheral nerves; guide for anterior-posterior bursal and intra-articular injections.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.399-402
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• 2005

For efficient and accurate diagnosis of ultrasound images, the time gain compensation (TGC) and dynamic range (DR) control of the ultrasound echo signal are important. TGC is for compensating the attenuation of the ultrasound echo signal along the depth, and DR is used to control the image contrast. In this paper, we propose an algorithm for finding the optimized values of TGC and DR automatically. For TGC, the degree of compensation is determined along the depth based on the effective attenuation estimation of ultrasound signal. For DR optimization, we introduce a novel cost function on the basis of the characteristics of ultrasound image, which provides the minimum value at the optimal DR. Experiments have been performed by applying the proposed algorithm to a real US imaging system. The results show that the algorithm automatically can determine the values of TGC and DR in realtime so that the subjective quality of the corresponding US image may be good enough for diagnosis.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.6 no.1
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• pp.28-37
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• 2013

Ultrasound is a first line examination of the knee and useful diagnostic tool in assessing the various knee lesions. The advantages of ultrasound are that it is non-invasive, easily available at bed side, cheap, well accepted by patients, and that it has technical benefits including dynamic evaluation. Its limitations include reliability, which is largely operator dependent and its inability to evaluate deep structures. Technical guidelines of the ultrasound released by European Society of MusculoSkeletal Radiology (ESSR) and ultrasonographic findings of various knee lesions are described.

• Clinics in Shoulder and Elbow
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• v.18 no.3
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• pp.172-193
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• 2015

Nowadays shoulder ultrasound is commonly used in the assessment of shoulder diseases and is as accurate as magnetic resonance imaging in the detection of several pathologies. Operator dependence is the main disadvantage of shoulder ultrasound. After adhering to a strict examination protocol, good knowledge of normal anatomy and pathologic processes and an awareness of common pitfalls, it can be used as a focused examination providing rapid, real-time diagnosis, and treatment by ultrasound-guided interventions in desired clinical situations. Also shoulder ultrasound can help the surgeon decide whether treatment will be surgical or nonsurgical. If arthroscopy is planned, sonographic findings help to counsel patients regarding surgical and functional outcomes. If a nonsurgical approach is indicated, ultrasound can be used to follow patients. This review article presents the examination techniques, the normal sonographic appearances and the main pathologic conditions found in shoulder ultrasound. And also addresses a simplified approach to scanning and ultrasound-guided intervention. Knowledge of optimal techniques, normal anatomy, dynamic maneuvers, and pathologic conditions is essential for optimal performance and interpretation of images.

• Journal of Biomedical Engineering Research
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• v.22 no.4
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• pp.321-330
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• 2001

In this paper, we propose a new synthetic aperture focusing scheme for improving the lateral resolution which is one of the most important factors determining the quality of ultrasound imaging. The proposed scheme enables full round-trip dynamic focusing with approximately limited property. This properties are obtained through transmitting plane waves of which the traveling angle varies with the receive subaperture position, as opposed to stepping the spherical wave source across an array in other synthetic aperture focusing schemes, and employing dynamic focusing in receive. In this paper, the properties of the proposed scheme is analyzed in which a hypothetical infinite line source is used to transmit the plane waves and verified through computer simulation results. Also, we show that the proposed scheme is realizable with an array transducer with a finite aperture size. In summary, it is shown through comparison between the field contours of the proposed scheme and the conventional scheme that the proposed scheme can improve greatly the lateral resolution of ultrasound imaging.

• Journal of the Korean Orthopaedic Association
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• v.55 no.5
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• pp.426-430
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• 2020

Magnetic resonance imaging and static ultrasound imaging do not indicate some cases of partial thickness tears of the supraspinatus tendon. The authors observed a partial thickness tear of the supraspinatus tendon that was not found using other imaging tools but was observed by resisted scaption in shoulder extension position dynamic ultrasound in several cases. This paper outlines this technique is reported by describing two cases.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.2 no.2
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• pp.94-98
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• 2009

Acupuncture is a treatment method that originated more than 3,000 years ago in China and is practiced in most of the world. Acupuncture became the most popular complementary and alternative medicine modality. Ultrasound is useful for research and educational purposes, visualizing needle insertion at acupuncture points, especially next to vulnerable structures such as nerves or the pleura. Additionally, ultrasound is an ideal imaging method for evaluation the biomechanical effects of needle manipulation on tissue and has the distinctive advantage of yielding both images of tissue morphology and biomechanical information. Elastography take aim at quantifying a mechanical response or the mechanical property of tissues from a mechanical stimulus, generated internally or externally. Therefore, the combination of ultrasound and elastography analyses allows quantitative assessment of dynamic changes in the structure of human connective tissue.

• Journal of Biomedical Engineering Research
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• v.27 no.1
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• pp.22-29
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• 2006

This paper proposes an efficient array beamforming method using spatial matched filtering for ultrasound imaging. In the proposed method, ultrasound waves are transmitted from an array subaperture with fixed transmit focus as in conventional array imaging. At receive, radio frequency (RF) echo signals from each receive channel are passed through a spatial matched filter that is constructed based on the system transmit-receive spatial impulse response. The filtered echo signals are then summed. The filter remaps and spatially registers the acoustic energy from each element so that the pulse-echo impulse response of the summed output is focused with acceptably low side lobes. Analytical beam pattern analysis and simulation results using a linear array show that the proposed spatial filtering method can provide more improved spatial resolution and contrast-to-noise ratio (CNR) compared with conventional dynamic receive focusing (DRF) method by implementing two-way dynamically focused beam pattern throughout the field.