• The Journal of the Society of Korean Medicine Diagnostics
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• v.20 no.1
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• pp.37-44
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• 2016

Ultrasonic imaging is the most widely modality among modern imaging device for medical diagnosis. Nevertheless, medical ultrasound images suffer from speckle noise and low contrast. In this paper, we propose probabilistic edge map for ultrasound image edge enhancement using automatic alien algorithm. The proposed method used applied speckle reduced ultrasound imaging for edge improvement using sequentially acquired ultrasound imaging. To evaluate the performance of method, the similarity between the reference and edge enhanced image was measured by quantity analysis. The experimental results show that the proposed method considerably improves the image quality with region edge enhancement.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.6
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• pp.521-537
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• 2000

Ultrasonic imaging is the most widely used modality among modern imaging device for medical diagnosis and the system performance has been improved dramatically since early 90's due to the rapid advances in DSP performance and VLSI technology that made it possible to employ more sophisticated algorithms. This paper describes "main stream" digital signal processing functions along with the associated implementation considerations in modern medical ultrasound imaging systems. Topics covered include signal processing methods for resolution improvement, ultrasound imaging system architectures, roles and necessity of the applications of DSP and VLSI technology in the development of the medical ultrasound imaging systems, and array signal processing techniques for ultrasound focusing.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.393-396
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• 2002

In this paper, we present a new method for generating a set of complementary sequences that can be simultaneously transmitted and yet compressed into a short pulse on reveive, and its application to ultrasound imaging. This new complementary sequences can be designed based on a filter bank theory. The new complementary sequences can be used to improve the SNR of ultrasound imaging without sacrificing the spatial resolution and frame rate, compared to conventional pulse-echo imaging. Computer simulations are performed to verify the proposed method.

• The Journal of the Acoustical Society of Korea
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• v.39 no.1
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• pp.16-23
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• 2020

In High-Intensity Focused Ultrasound (HIFU) treatment, effective localization of HIFU focus is important for developing a safe treatment plan. While Magnetic Resonance Imaging guided HIFU (MRIgHIFU) can visualize the ultrasound path during the treatment for localizing HIFU focus, it is challenging in ultrasound imaging guided HIFU (USIgHIFU). In the present study, a real-time ultrasound beam visualization technique capable of localizing HIFU focus is presented for USIgHIFU. In the proposed method, a short pulse, with the same center frequency of an imaging ultrasound transducer below the regulated acoustic intensity (i.e., Ispta < 720 mW/㎠), was transmitted through a HIFU transducer whereupon backscattered signals were received by the imaging transducer. To visualize the HIFU beam path, the backscattered signals underwent dynamic receive focusing and subsequent echo processing. From in vitro experiments with bovine serum albumin gel phantoms, the HIFU beam path was clearly depicted with low acoustic intensity (i.e., Ispta of 94.8 mW/㎠) and the HIFU focus was successfully localized before any damages were produced. This result indicates that the proposed ultrasound beam path visualization method can be used for localizing the HIFU focus in real time while minimizing unwanted tissue damage in USIgHIFU treatment.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.1
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• pp.80-87
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• 1998

In this study, a multi-element ultrasound transducer has been developed aiming at basic experiment of three-dimension endovascular ultrasound endscopy for clinical diagnos, and experimental results of two-dimensional object imaging in the water are presented by the ultrasound tranducer and neural network. Each ultrasound echo received by thirty-six angular transducer elements is inputed to the eural network, and then backpropagation is used as a learning algorithm. A three-layer artificial neural network is used for learning and imaging of targetw placed in front of the transducer. The object shape of imaging is restricted to rectangular shapes by considering experimental restraint conditions. As a result, rough visualization can be realized even for objects with unlearned shapes through the training by primitive patterns of a various sized rectangular targets.

• Journal of Biomedical Engineering Research
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• v.30 no.3
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• pp.233-240
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• 2009

Using a spatial compound imaging technique in a medical ultrasound imaging system, the average speed of sound in a medium of interest is measured, and imaging of its distribution is implemented. When the brightness reaches the highest level in an ultrasonic image obtained as the speed of sound used in focusing is varied, it turns out that the focusing has been accomplished satisfactorily and that the speed of sound which has been adopted becomes the sought-after average speed of sound. Because spatial compound imaging provides many different views of the same object, the adverse effect of erroneous speed-of-sound estimation tends to be more severe in compound imaging than in plain B-mode imaging. Thus, in compound imaging, the average speed of sound even in the case of speckled images can be accurately estimated by observing the brightness change due to different speeds of sound employed. Using this new method that offers spatial diversity, we can construct an image of the speed of sound distribution in a phantom embedded with a 10-mm diameter plastic cylinder whose speed of sound is different from that of the background. The speed of sound in the cylinder is found to be different from that of the surrounding medium.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2349-2351
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• 2010

Photo Acoustic Tomography (PAT) is a hybrid imaging modality which combines high contrast of optical imaging and spatial resolution of ultrasound imaging, thus it is suitable to image biological tissue noninvasively. Laser-induced photoacoustic signals were measured from a sample by means of an unfocused ultrasound transducer, then PAT image was reconstructed based on a universal back-projection algorithm. To evaluate the feasibility of our system, phantom test was performed, consequently, the PAT images obtained using our system showed highly analogous shape and volume with those of the phantom. This result demonstrated that our system can provide a powerful tool for imaging the substructure of biological tissue in non-invasive manner.

• The Journal of the Acoustical Society of Korea
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• v.36 no.4
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• pp.238-246
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• 2017

High frequency ultrasound imaging typically suffers from low sensitivity due to the small aperture of high frequency transducers and shallow imaging depth due to the frequency-dependent attenuation of ultrasound. These limitations should be overcome to obtain high-frequency, high- resolution ultrasound images. One practical solution to the problems is a high-performance signal receiver capable of detecting a very small signal and amplifying the signal with minimal electronic noise addition. This paper reports a recently developed low-noise, wideband ultrasound receiver for high-frequency, high-resolution ultrasound imaging. The developed receiver has an amplification gain of up to 73 dB and a variable amplification gain range of 48 dB over an operating frequency of 80 MHz. Also, it has an amplification gain flatness of ${\pm}1dB$. Due to these high performances, the developed receiver has a signal-to-noise ratio of at least 8.4 dB and a contrast-to-noise ratio of at least 3.7 dB higher than commercial receivers.

• The Journal of Korean Physical Therapy
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• v.25 no.2
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• pp.76-80
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• 2013

Purpose: The objective of this study was to offer primary clinical data examining whether change of imaging structure and quantitative evaluation of muscle activity on myofascial trigger points can lead to implementation of an analytical technique for evaluation of myofascial pain diagnoses. In addition, we examined the effect of a variety of mediation techniques, in order to examine neuromuscular physiological characteristics of myofascial trigger points muscle by comparing differences in pressure pain threshold and ultrasound imaging. Methods: Participants in the study included 30 adults in their twenties. The subjects were divided into the normal and myofascial trigger points groups. Clinical outcomes were evaluated by pressure pain threshold for pain and ultrasound imaging was performed for evaluation of the structural characteristics of muscle. Independent t-test was used for statistical analysis. Results: The two groups showed statistical significance in the change in pressure pain threshold (p<0.05). Findings of ultrasound imaging analysis showed no significant differences, increased muscle thickness was observed (p>0.05). Findings of ultrasound imaging analysis showed significant differences, increased muscle echodensity was observed (p<0.05). Findings on ultrasound imaging analysis showed significant differences, increased muscle white area index was observed (p<0.05). Conclusion: From these results, active myofascial trigger points muscle showed quality deterioration on ultrasound imaging. Thorough evaluation of imaging structure and physiological characteristics can be useful quantitative analytical techniques for diagnosis of myofascial pain syndrome and a primary factor reflected in physical therapy intervention.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.573-584
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• 2012

Breast and prostate tumors or cancers tend to be stiffer than the surrounding normal tissue. However, the difference in echogenicity between cancerous and normal tissues is not clearly distinguishable in ultrasound B-mode imaging. Thus, imaging the stiffness contrast between the two different tissue types helps to diagnose lesions quantitatively, and such a method of imaging the elasticity of human tissue is termed ultrasound elasticity imaging. Recently, elasticity imaging has become an effective complementary diagnostic modality along with ultrasound B-mode imaging. This paper presents various elasticity imaging methods that have been reported up to now and describes their characteristics and principles of operation.