• Journal of the Korean Wood Science and Technology
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• v.48 no.3
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• pp.364-375
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• 2020

In this study, ultrasound-assisted extraction was performed to extract ascorbic acid from rugosa rose (Rosa rugosa Thunb.) fruit. The optimal conditions were investigated by response surface methodology, using two variable including reaction time (16-44 min) and temperature (16-44℃). The ascorbic acid extraction was sensitive to the reaction time rather than the reaction temperature, and the optimal conditions for ascorbic acid extraction were 25℃ and 30 min. Ascorbic acid and gallic acid in the rugosa rose fruit extract were completely separated by HPLC, with a resolution factor of over 1.5 between the two. The correlation coefficient of the ascorbic acid was 0.999 in a linearity test for 50-150 ㎍/mL concentration of extract. The limit of detection and limit of quantification values were 0.16 ㎍/mL and 29.89 ㎍/mL, respectively. The relative standard deviations (RSD) for repeatability and reproducibility were determined, and each RSD showed good precision at less than 5% (N=6).

• Journal of Embryo Transfer
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• v.15 no.1
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• pp.1-8
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• 2000

The ultrasound-guided oocytes cllection (ovum pick-up ; OPU) has become a substitution for superovlation in cattle. The objective of this study was to examine the effect of OPU frequency on the in vitro production of embryos in Hanwoo cattle. Six cycling Hanwoo cows were distributed into two groups for either once or twice weekly OPU sessions. Oocytes were collected by ultrasound-guided follicle aspiration(SA600) using a 6.5HMz transducer and attached with 18 gauge needle, with vacuum pressure of 40 mmHg. The cumulus-oocyte complexes (COCs) collected from each donor were matured in TCM 199 supplemented with 10% fetal bovine serum at 5% CO2 in air at 38.5$^{\circ}C$ for 22h and in vitro matured oocytes were co-incubated with sperm(separated by Percoll gradient) for 6h. The zygotes were co-cultured on cumulus cell monolayer in 10ul droplets in the same culture medium and conditions used for IVM for 7 days. On Day 7 of culture, development to blastocysts was examined. Although the number of oocytes collected was variable depending on individuals, overall embryo production in the twice per week OPU sessions was better that in the once per week sessions(6~21 vs 2~7 blastocysts produced, respectively). Two cows(E, A) were good oocyte donors and embryo production was superior in cow C ; however, cow F was a poor donor as compared to the others. In conclusion, these results suggest that for embryo production, twice weekly OPU sessions were better than once per week for producing embryos in vitro from Hanwoo cattle.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.484-493
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• 2012

Since the 1980s, there have been many research activities devoted to quantitatively characterizing and imaging human tissues based on sound speed, attenuation coefficient, density, nonlinear B/A parameter, etc., but those efforts have not yet reached the stage of commercialization. However, a new imaging technology termed elastography, which was proposed in the early 1980s, has recently been implemented in commercial clinical ultrasound scanners, and is now being used to diagnose prostates, breasts, thyroids, livers, blood vessels, etc., more quantitatively as a complementary adjunct modality to the conventional B-mode imaging. The purpose of this article is to introduce and review various elastographic algorithms for use in quasistatic or static compression type elasticity imaging modes. Most of the algorithms are based on the crosscorrelation or autocorrelation function methods, and the fundamental difference is that the time shift is estimated by changing the lag variable in the former, while it is directly obtained from the phase shift at a fixed lag in the latter.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.751-759
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• 2023

Breast ultrasonography is difficult to image in fatty breasts and to find micro-calcification, but the discovery of micro-calcification is very important for breast cancer screening. Among the color Doppler artifact of ultrasound, twinkle artifact mainly occur on strong reflectors such as stones or calcification in images, and evaluation methods using them are clinically being used. In this study, we are conducting experiments on the color Doppler settings of ultrasound equipment, such as repetition frequency, ensemble, persist, wall filtering, smoothing, linear density, and dissociation value, by producing a breast simulation phantom using the largest amount of calcium phosphate among breast implants. The purpose of this study was to improve the contrast of twinkle artifact in breast ultrasound examinations and to maximize their use in clinical practice. As a result, the pulse repetition frequency occurred in the range of 3.6 kHz to 7.2 kHz, and did not occur above 10.5 kHz. For ensembles, twinkle artifact occurred in all sizes of calcification under low conditions, and in threshold settings, the twinkle artifact increased slightly only under 80 to 100 conditions, and did not occur in 1 mm size calcification. Persist, wall filter, smoothing, and line density settings did not have much meaning in the setting variable because conditions did not increase by condition, and pulse repetition frequency, ensemble, and thresholds had the greatest impact on the twinkling artifact image. This study is expected to help examiners select optimal conditions to effectively increase twinkle artifact by adjusting color Doppler settings.

• Korean Journal of Bronchoesophagology
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• v.15 no.2
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• pp.30-35
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• 2009

Lung cancer could be developed through a series of morphological changes from dysplasia to carcinoma in situ and then invasive cancer. However, precancerous lesions are generally a few cell layers thick and are detected only by chance. Autofluorescence bronchoscopy(AFB) is one of the newly developed diagnostic tools to detect the pre-cancerous lesions m the bronchial tissue. Several studies have shown that AFB improved the rate of detection of cancer and dysplastic lesions of the airway, especially those in intraepithelial stage. However, there were high rates of false positive with AFB, and it is also important to develop non-biopsy methods because of lack of accurate information of variable course of preneoplastic lesions regarding progression. So, many other technologies were developed, such as narrow band imaging(NBI), endobronchoscopic ultrasound, optical coherence tomography, and confocal fluorescence microendoscopy. Among the new machines, NBI is a new optical technology that can clearly visualize the microvascular structure m the mucosal layer. NBI seems to increase specificity without compromising sensitivity. In the future such techniques would make it possible to precisely study in detail the natural history of the premalignant epithelium.

• 전기의세계
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• v.31 no.3
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• pp.204-208
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• 1982

The objective of this paper is to present a digital method for improving the lateral resolution of the B-scan images in the medical applications of ultrasound. The method is based upon a mathematical model of the lateral blurring caused by the finite beam width of the transducers. This model provides a simple method of applying a recursive scheme for image restoration with fast computation time. The point spread function (P.S.F.) can be measured by the reflective signals after scanning the small pins located along the depth of interest. From the measured P.S.F., one can compute the coefficient matrices of the inverse discrete-time dynamic state variable equation of the blurring process. Then, a recursive scheme for deblurring is applied to the recorded B-scan to improve the lateral resolution. One major advantage of the present recursive scheme over the transform method is in its applicability for the space-variant imaging, such as in the case of the rotational movement of transducer.

• Journal of Korea Association of Health Promotion
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• v.4 no.1
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• pp.12-27
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• 2006

"본 논문은 대한내과학회지 2006년 제70권 제3호에 실렸던 논문으로 대한내과학회 편집위원회의 승인을 득하고 본 협회지에 게재함. Background : Diabetes mellitus is a major independent risk factor for atherosclerosis. In recent years non-invasive high resolution B-mode ultrasound methods have been developed to measure the intima-media thickness(IMT) of the carotid artery as an indicator for early atherosclerosis. Itis known that obesity plays a role in the development of type 2 diabetes and cardiovascular disease, and it has also been reported that not only the amount but also the distribution of body fat is important. This study investigated the relationship between obesity and the development of carotid atherosclerosis in type 2 diabetic patients. Methods: Carotid IMT was measured by ultrasound B-mode imaging in 144 patients with type 2diabetes mellitus. All subjects underwent assessment for the degree and distribution of obesity, the presence of coronary artery disease risk factors, and the presence of diabetic complications. Resuts: Carotid IMT was increased in the abdominal obese group defined by waist circurference. However, there was no significant difference in carotid TMT between the non-obese group and obese group as defined by body mass index, waist to hip ratio, and total body fat percent measured by bio electrical impedance analysis. There were positive correlations between carotid IMT and age, duration of diabetes, systolic blood pressure, and waist circumference. Multiple linear regression analysis revealed the variable that interacted independently with carotid IMT was age in type 2 diabetic patients. Carotid IMT was significantly increased in type 2 diabetic patients with macrovascular complications and microvascvlar complications .Conclusion: This study suggested that abdominal obesity rather than general obesity was associated with carotid atherosclerosis reflected by increment of carotid IMT in type 2 diabetic subjects.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.4
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• pp.290-298
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• 2014

Ultrasonic thickness measurement is a non-destructive method to measure the local thickness of a solid element, based on the time taken for an ultrasound wave to return to the surface. When an element is very thin, it is difficult to measure thickness with the conventional ultrasonic thickness method. This is because the method measures the time delay by using the peak of a pulse, and the pulses overlap. To solve this problem, we propose a method for measuring thickness by using the power cepstrum and the minimum variance cepstrum. Because the cepstrums processing can divides the ultrasound into an impulse train and transfer function, where the period of the impulse train is the traversal time, the thickness can be measured exactly. To verify the proposed method, we performed experiments with steel and, acrylic plates of variable thickness. The conventional method is not able to estimate the thickness, because of the overlapping pulses. However, the cepstrum ultrasonic signal processing that divides a pulse into an impulse and a transfer function can measure the thickness exactly.

• Journal of the Korean Society of Radiology
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• v.13 no.4
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• pp.547-555
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• 2019

The purpose of this study was to evaluate the usefulness of routine liver ultrasonography on the basis of the scoring system according to the morphological parameters of liver ultrasound images and the histopathological results of liver biopsy. The morphological parameters of the liver through ultrasonography were divided into liver surface, liver edge and liver parenchyma. Pathologic results of liver biopsy were classified as mild fibrosis(F1), significant fibrosis(F2), severe fibrosis(F3), and cirrhosis(F4). In conclusion, routine ultrasound examination showed a sensitive predictive factor for fibrosis with mild fibrosis (F1) to severe fibrosis (F3) were liver edge>liver parenchyma>liver surface. However, the predictive factors for detecting cirrhosis (F4) were liver parenchyma>liver surface>liver edge. The use of three variable combinations rather than individual variables in routine ultrasonography may be useful in evaluating the degree and progress of liver fibrosis.

• Journal of the Korean Society of Radiology
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• v.11 no.5
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• pp.407-412
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• 2017

This study investigates the correlations between the total prostate volume (TPV), using the prostate specific antigen (PSA) and prostate specific antigen density (PSAD) as the blood test results and transrectal ultrasound (TRUS), and the prostate transition zone volume (PTZV), as well as variables such as age; the findings can be used as clinical indicators. A retrospective analysis was conducted on 68 healthy men in their 30s who underwent TRUS and PSA and PSAD blood tests from June 2007 to April 2016, with no history of treatment in their prostate. Siemens Acuson sequoia 512 and the probe Siemens EC-10C5 Endocavitary were used as the ultrasound equipment. For statistical analysis, SPSS 18.0 was used to calculate the standard deviation and mean of each variable; Pearson's correlation analysis was also performed. The descriptive statistics of the variables were $24.27{\pm}6.60$ for TPV, $6.99{\pm}6.60$ for PTZV, $2.12{\pm}2.76$ for PSA, and $0.281{\pm}0.1$ for PSAD. The coefficients of correlations between PTZV and variables were 0.831 for PSAD, 0.707 for TPV, 0.398 for age, and 0.118 for PSA. While PSA and age were positively correlated, PSAD and TPV were highly correlated. Therefore, PTZV of men in their 30s without underlying diseases can be predicted using PSAD and TPV.