• 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.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1417-1422
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• 2009

This study was conducted to investigate the effect of ultrasound with ascorbic acid on the quality of fresh-cut apples. Prepared apple cubes were dipped in distilled water (US) or in 1% ascorbic acid solution (AS), both were treated with ultrasound at 40 kHz, while the other sample was just dipped in 1% ascorbic acid solution for 1 min (AA). All samples were stored at $4^{\circ}C$ for 12 days. AS treatment had an effect on apple cube color as indicated by its significantly higher L values and lower ${\Delta}E$ value whereas AA- and US-treated samples showed a considerable browning. Higher inhibition rate on browning and polyphenol oxidase (PPO) activity of 46 and 98%, respectively, were observed after AS treatment. The highest total phenolic content of AS-treated samples was shown during whole storage periods. This investigation revealed that the use of ultrasound in combination with ascorbic acid had a positive effect on quality maintaining of fresh-cut apples.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.135-144
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• 2024

Ultrasonography examination has limitations in quantifying hepatic fat quantification. Therefore, this study aimed to experimentally demonstrate whether changes in signal attenuation during ultrasound imaging can be quantified using simulated hepatic phantoms to assess hepatic fat content. Additionally, we aimed to evaluate the potential of ultrasound imaging for diagnosing hepatic fatty liver by analyzing the relationship between hepatic fat content and signal intensity in ultrasound images. In this study, we developed a total of five stimulated hepatic phantoms by homogeneously mixing water and oil. We confirmed the fat content of the phantoms using magnetic resonance imaging (MRI) and ultrasound imaging, and measured signal intensity according to distance in ultrasound images to analyze the correlation and mean comparison between fat content and signal intensity. We observed that as the fat content increased, the ultrasound penetration intensity decreased, confirming the potential for quantifying hepatic fat content using ultrasound. Additionally, the analysis of the correlation between the measured fat content using MRI and the signal intensity measured in ultrasound images showed a high correlation. Statistical analysis in our study confirmed that as the fat content increased, the slope representing signal during ultrasound imaging (US-GRE) decreased. In this study, it was statistically confirmed that the US-GRE value of ultrasound images gradually decreases as the fat content increases, and it is believed that US-GRE can serve as a biomarker expressing fatty liver content.

• Food Science and Preservation
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• v.19 no.3
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• pp.323-327
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• 2012

The effects of ultrasound and ascorbic acid cotreatment on the browning inhibition and microbial growth of fresh-cut Tsugaru apples were investigated. The prepared samples were dipped in distilled water (Cont) or 1% (w/v) ascorbic acid solution (AA) and were then ultrasonicated in distilled water (US) or 1% (w/v) ascorbic acid solution (AA+US). The samples were then packed in a 0.04mm polypropylene bag ($20{\times}15$ cm) and were stored at $10^{\circ}C$ for eight days. The AA+US treated samples showed high $L^*$ and low $a^*$, $b^*$ values as well as inactivated PPO activity. The growth of the total aerobic bacteria also inhibited the AA+US treated samples more. The physicochemical properties were not different among all the samples. It was demonstrated in this paper that the ultrasonication treatment with ascorbic acid prevented the enzymatic browning of and microbial growth in fresh-cut Tsugaru apples.

• 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.

• Food Science and Preservation
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• v.17 no.2
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• pp.202-207
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• 2010

The effects of ultrasound treatment, in combination with ascorbic acid, on the quality of fresh-cut 'Jonathan' apples was investigated. Prepared apple slices were ultrasonicated in distilled water (US) or in 1%(w/v) ascorbic acid solution (UA) and the other samples were just dipped in 1%(w/v) ascorbic acid solution (AA). All samples were stored at$10^{\circ}C$ for 12 days. UA-treated samples showed high $L^{*}$ and hue values and low $a^{*}$, $b^{*}$, chroma, and ${\Delta}E$ value. Both control and US-treated samples showed considerable browning. A significant inhibition of polyphenol oxidase activity was observed after UA treatment. The level of total phenolics in UA-treated samples was higher on the day of treatment compared with other samples. Total soluble solids, pH, titratable acidity, and gas concentrations were similar in all samples. This study demonstrated that the simultaneous treatment of ultrasound and ascorbic acid was effective in preventing enzymatic browning of fresh-cut 'Jonathan' apples and maintaining total phenolics contents.

• The Journal of the Acoustical Society of Korea
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• v.29 no.2E
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• pp.73-85
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• 2010

In the diagnostic ultrasound (US) transducer technology, the high frequency US(HFUS) transducer over 20 MHz is one of the current issues to be pursued for better resolution with the expense of penetration. HFUS single element transducers and the mechanical scanning systems for imaging are reviewed, and HFUS array transducers are also briefly summarized. HFUS applications such as the human applications in ophthalmology and dermatology and small animal applications for research purposes are reviewed with vascular and blood imaging in this paper.

• Bulletin of Food Technology
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• v.23 no.3
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• pp.392-399
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• 2010

최근 초음파(ultrasound, US) 기술의 원리와 응용, 특히 식품의 생리활성물질에 관련된 응용기술에 대하여 기술하였다. 간단한 초음파 기술은 제외하고, 유화, 용해, 조직개선, 균질화(homogenization), 점도, 추출, 건조, 결정화, 거품제거(defoaming) 등의 기술에 관한 것이다. 특히 초음파에 의한 추출(UAE)을 상세히 기술하였다. 오늘날 초음파 기술은 생리활성물질의 추출 같은 산업화에 응용되고 있으며, 기능성을 강화하기 위한 추출에도 이용하고 있다. 이러한 초음파 기술은 장래 효과적인 식품기술이 될 것이며, 또한 식품의 성질을 이해하는 데 도움이 될 것이다.

• The Korean Journal of Pain
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• v.30 no.1
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• pp.66-70
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• 2017

The lumbar sympathetic ganglion block (LSGB) is widely used for diagnosing and treating sympathetically maintained pain disorders. The LSGB has been conventionally carried out under fluoroscopy or computed tomography guidance. However, as ultrasound technology improved, ultrasound-guided interventions have been expanding their territory to deeper structures. Ultrasound guidance provides many benefits including protecting vascular injection, shortening procedure time in some cases, and reducing the emission of radiation. In this report, we describe a successful case of a US-guided LSGB without major complications. We expect that US-guided LSGBs can be implemented and furnished in the daily outpatient clinical setting by highly trained pain physicians.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.503-509
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• 2018

Endive is widely consumed in a fresh-cut form owing to its rich nutritional content. However, fresh-cut vegetables are susceptible to contamination by pathogenic bacteria. This study investigated the antibacterial activities of the combined treatment of cinnamon leaf oil emulsion containing cetylpyridinium chloride or benzalkonium chloride (CLC and CLB, respectively) as a cationic surfactant and ultrasound (US) against Listeria monocytogenes and Escherichia coli O157:H7 on endive. The combined treatment of CLC or CLB with US reduced the population of L. monocytogenes by 1.58 and 1.47 log colony forming units (CFU)/g, respectively, and that of E. coli O157:H7 by 1.60 and 1.46 log CFU/g, respectively, as compared with water washing treatment. The reduction levels of both pathogens were higher than those observed with 0.2 mg/ml sodium hypochlorite. In addition, the combined treatment showed no effect on the quality of the fresh-cut endive (FCE). In particular, the degree of browning in FCE was less for the treatment group than for the control and water washing treatment groups. Thus, cationic surfactant-based cinnamon leaf oil emulsions combined with US may be an effective washing treatment for the microbial safety of FCE.