• Journal of Yeungnam Medical Science
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• 제39권3호
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• pp.190-199
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• 2022

Ultrasound-guided injection is useful for managing thoracic spine and chest wall pain. With ultrasound, pain physicians perform the injection with real-time viewing of major structures, such as the pleura, vasculature, and nerves. Therefore, the ultrasound-guided injection procedure not only prevents procedure-related adverse events but also increases the accuracy of the procedure. Here, ultrasound-guided interventions that could be applied for thoracic spine and chest wall pain were described. We presented ultrasound-guided thoracic facet joint and costotransverse joint injections and thoracic paravertebral, intercostal nerve, erector spinae plane, and pectoralis and serratus plane blocks. The indication, anatomy, Sonoanatomy, and technique for each procedure were also described. We believe that our article is helpful for clinicians to conduct ultrasound-guided injections for controlling thoracic spine and chest wall pain precisely and safely.

• 한국음향학회지
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• 제31권8호
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• pp.580-589
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• 2012

이 논문에서는 휴대용, 또는 저가형 초음파진단기에 비교적 고급 기능인 도플러 갭 필링 모드를 적용하고자할 때 적합한 알고리즘들을 찾아보았고, 그 결과 미러링 기반, 또는 자기회귀 모델 기반의 알고리즘들을 찾을 수 있었다. 또, 계산량이 지나치게 많아지지 않는 범위 내에서, 그러한 알고리즘들의 성능의 문제점을 보완하여 더욱 개선시켰다. 수정된 알고리즘들은 인공적으로 발생시킨 도플러 신호 및 실제 초음파장비를 써서 인체로부터 획득한 도플러 데이터를 써서 시뮬레이션 및 실험을 함으로써 유효성을 확인하였다.

• 대한의용생체공학회:의공학회지
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• 제26권1호
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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.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7731-7736
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• 2013

Aim: To compare the agreement of screening breast mammography plus ultrasound and reviewed mammography alone in asymptomatic women. Materials and Methods: All breast imaging data were obtained for women who presented for routine medical checkup at National Cancer Institute (NCI), Thailand from January 2010 to June 2013. A radiologist performed masked interpretations of selected mammographic images retrieved from the computer imaging database. Previous mammography, ultrasound reports and clinical data were blinded before film re-interpretation. Kappa values were calculated to assess the agreement between BIRADS assessment category and BIRADS classification of density obtained from the mammography with ultrasound in imaging database and reviewed mammography alone. Results: Regarding BIRADS assessment category, concordance between the two interpretations were good. Observed agreement was 96.1%. There was moderate agreement in which the Kappa value was 0.58% (95%CI; 0.45, 0.87). The agreement of BI-RADS classification of density was substantial, with a Kappa value of 0.60 (95%CI; 0.54, 0.66). Different results were obtained when a subgroup of patients aged ${\geq}60$ years were analyzed. In women in this group, observed agreement was 97.6%. There was also substantial agreement in which the Kappa value was 0.74% (95%CI; 0.49, 0.98). Conclusions: The present study revealed that concordance between mammography plus ultrasound and reviewed mammography alone in asymptomatic women is good. However, there is just moderate agreement which can be enhanced if age-targeted breast imaging is performed. Substantial agreement can be achieved in women aged ${\geq}60$. Adjunctive breast ultrasound is less important in women in this group.

• 대한의용생체공학회:의공학회지
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• 제9권1호
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• pp.87-92
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• 1988

In this paper, a new focusing method, to be called the pipelined sampled delay focusing (PSDF), is implemented. This method improves the lateral resolution in ultrasound imaging system. In PSDF, the analog belay lines are no longer necessary because sampling sum process can replace the conventional delay sum process. Also, the method offers continuous dynamic focusing on the resolution pixel basis, and eliminates the constraint that the maximum delay time is less than the sampling interval. Second order sampling is adopted in order to extend the sampling interval.

• 비파괴검사학회지
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• 제34권6호
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• pp.441-446
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• 2014

A 3D ultrasound image is desired in many medical examinations. However, the implementation of a 2D array, which is needed for a 3D image, is challenging with respect to fabrication, interconnection and cabling. A 2D sparse array, which needs fewer elements than a dense array, is a realistic way to achieve 3D images. Because the number of ways the elements can be placed in an array is extremely large, a method for optimizing the array configuration is needed. Previous research placed the target point far from the transducer array, making it impossible to optimize the array in the operating range. In our study, we focused on optimizing a 2D sparse array transducer for 3D imaging by using a simulated annealing method. We compared the far-field optimization method with the near-field optimization method by analyzing a point-spread function (PSF). The resolution of the optimized sparse array is comparable to that of the dense array.

• 대한의용생체공학회:의공학회지
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• 제33권1호
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• pp.32-38
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• 2012

Recently, several ultrasound imaging techniques for tissue characterization have been developed. Among them, ultrasound elastography is regarded as the most promising modality and has been rapidly developed. One of ultrasound elastography techniques is shear modulus imaging. Normal and cancerous tissues show big difference of shear moduli and they have good image contrast. However shear wave elastography requires more complicated hardware and more computations for image reconstruction algorithm. Therefore new efficient techniques are being developed. In this paper, we have developed a very flexible ultrasound system for elastography experiments. The developed system has capabilities to acquire ultrasound RF data of all channels and generate arbitrary ultrasound pulse sequences. It has a huge amount of memories for RF data acquisition and a simple and flexible pulse generator. We have verified the performance of the system showing conventional B-mode images and preliminary results of elastography. The developed system will be used to verify our own reconstruction algorithm and to develop more efficient elastography techniques.

• Korean Journal of Radiology
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• 제19권6호
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• pp.1196-1197
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• 2018

• Korean Journal of Radiology
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• 제23권4호
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• pp.492-493
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• 2022

• 한국음향학회지
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• 제41권5호
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• pp.534-544
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• 2022

초음파진단기는 실시간으로 손쉽고 안전하게 환자의 병변을 관찰할 수 있는 등의 다양한 장점으로 인해 병원, 의원 등의 의료현장에서 널리 활용되고 있다. 이 초음파진단기 신호처리 블록 중 하나인 빔포머는 초음파진단기 영상의 화질을 결정하는 부분 중 하나이다. 초음파진단기 기술의 발전과 더불어 이 빔포머와 관련된 기술들도 장기간 많은 발전을 이루어 왔는데, 이 기술들 중 하나의 주요 방법인 합성구경영상법(Synthetic Aperture Imaging method, SAI)은 프로브를 통해 수신한 신호가 운반해 온 환자로부터의 정보를 최대로 활용하기 위한 방법으로, 1990년대 경 최초로 초음파진단기에 도입된 이래 획기적 화질 향상에 기여해 왔고, 수십년동안 다양한 형태의 발전을 거쳐왔다. 이 논문에서는 이러한 진화과정을 살펴보고, 이 기술의 미래의 발전 방향을 예상해 본다.