• Asian Pacific Journal of Cancer Prevention
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• v.13 no.2
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• pp.493-497
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• 2012

This study was conducted to retrospectively evaluate the pattern of contrast enhancement with SonoVue on gray-scale ultrasonography of hepatic angiomyolipoma (HAML). Imaging features of 33 pathologically proven HAML lesions in 33 patients who underwent baseline ultrasound and contrast-enhanced ultrasonography (CEUS) were assessed retrospectively. All lesions were enhanced in the arterial phase and showed whole-tumor filling in. Thirty-two of 33 (97%) lesions showed early positive enhancement in the arterial phase. Twenty-three of these exhibited isoechoic or hyperechoic features in the portal phase. HAML demonstrate characteristic manifestations with SonoVue-enhanced real-time gray-scale ultrasonography.

• Journal of Biomedical Engineering Research
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• v.36 no.5
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• pp.162-168
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• 2015

In this study, we suggested the performance and safety testing guideline for low intensity pulsed ultrasound (LIPUS) represented by the ultrasound fracture treatment device and cartilage treatment device and low intensity focused ultrasound (LIFU) represented by ultrasonic face lifting device. For these study, the international standards and management regulations of Korea, Japan and United State were analyzed. And the usefulness and applicability were evaluated by testing with commercial equipment and reflecting the views of the industry and experts. As a result of this study, the safety and performance test guidelines for low intensity therapeutic ultrasound device were proposed by presenting the 10 items for LIPUS and 12 items for LIFU. The suggested guidelines are considered a high utilization in the domestic testing and approval authorities. And they are also thought to be useful to new technology development.

• Journal of Biomedical Engineering Research
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• v.19 no.3
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• pp.321-325
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• 1998

This paper presents a simple, practical, and efficient method for estimating the speed of sound in reflection mode in ultrasound medical imaging. Its accurate determination is indispensable in order to obtain both good resolution and correct geometrical and volumetric information about human organs such as heart and kidney. Up to now, there have been several methods available, but they all suffer from either poor performance or high complexity. The proposed method finds out an optimum focusing delay profile in such a way that the brightness in a region of interest is maximized using continuous dynamic focusing in receive under fixed transmit focusing. Experiments carried out on a real ultrasound medical phantom reveals that the method a quite simple and effective in providing good speed of sound estimation, hence improved resolution and images, adding to dignostic utility.

• Journal of Korea Multimedia Society
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• v.20 no.1
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• pp.43-50
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• 2017

According to living environment, the number of deaths due to thyroid diseases increased. In this paper, we proposed an algorithm for recognizing a thyroid detection using texture analysis based on shape, gray level co-occurrence matrix and gray level run length matrix. First of all, we segmented the region of interest (ROI) using active contour model algorithm. Then, we applied a total of 18 features (5 first order descriptors, 10 Gray level co-occurrence matrix features(GLCM), 2 Gray level run length matrix features and shape feature) to each thyroid region of interest. The extracted features are used as statistical analysis. Our results show that first order statistics (Skewness, Entropy, Energy, Smoothness), GLCM (Correlation, Contrast, Energy, Entropy, Difference variance, Difference Entropy, Homogeneity, Maximum Probability, Sum average, Sum entropy), GLRLM features and shape feature helped to distinguish thyroid benign and malignant. This algorithm will be helpful to diagnose of thyroid nodule on ultrasound images.

• Journal of Radiation Protection and Research
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• v.24 no.1
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• pp.23-30
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• 1999

Pregnant ICR mice were treated with 137Cs gamma-ray / ultrasound on day 8 of gestation. In combined treatments, pregnant mice were treated with both 1.5 Gy of radiation and $1.0W/cm^2$ ultrasound at time intervals of -1, 0, 1, 3 and 6 hours. The mortalities and external malformations were investigated on day 18 of gestation. The threshold dose of mortality induced by radiation on day 8 of gestation was between 0.5 and 1.0 Gy, and that which was induced by ultrasound was between 1.0 and $1.5W/cm^2$. The mortalities in the late-stage of gestation induced by combined treatment with radiation and ultrasound increased synergistically. The threshold dose of exencephaly and anophthalmia induced by radiation were between 0.5 and 1.0 Gy and between 1.0 and 1.5 Gy, respectively. Those of exencephaly and anophthalmia induced by ultrasound were between 1.0 and $1.5W/cm^2$ and more than $1.5W/cm^2$, respectively. In combined treatments, the incidence of exencephaly and anophthalmia were found to increase synergistically. In the mice treated with both agents at a time interval of one hour, the incidence of exencephaly and anophthalmia reached maximum levels.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.693-699
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• 2023

Ultrasound is widely used in the medical field for non-destructive and non-invasive disease diagnosis. In order to improve the disease diagnosis accuracy of diagnostic medical images, improving spatial resolution is a very important factor. In this study, we aim to model the super resolution convolutional neural network (SRCNN) algorithm in ultrasound images and analyze its applicability in the medical diagnostic field. The study was conducted as an experimental study using Field II simulation and open source clinical liver hemangioma ultrasound imaging. The proposed SRCNN algorithm was modeled so that end-to-end learning can be applied from low resolution (LR) to high resolution. As a result of the simulation, we confirmed that the full width at half maximum in the phantom image using a Field II program was improved by 41.01% compared to LR when SRCNN was used. In addition, the peak to signal to noise ratio (PSNR) and structural similarity index (SSIM) evaluation results showed that SRCNN had the excellent value in both simulated and real liver hemangioma ultrasound images. In conclusion, the applicability of SRCNN to ultrasound images has been proven, and we expected that proposed algorithm can be used in various diagnostic medical fields.

• The Journal of the Acoustical Society of Korea
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• v.42 no.3
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• pp.203-213
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• 2023

In medical ultrasound imaging systems, Side lobes may appear if signals outside the imaging point are not completely removed during receive focusing. If the time signal of the side lobe overlaps with the time signal (main lobe) from the image point, it is difficult to completely remove it using filter processing in the time domain. However, In the receive focusing process, when time-channel signals are Fourier-transformed, the main lobe and side lobe signals are spatially separated in the spectral domain. Therefore, the side lobes can be suppressed by multiplying the image with magnitude weights, which are determined by the magnitudes of the main and side lobes calculated in the spectral domain. In addition, when the main lobe and the side lobe spectrum are adjacent, the distance weight was applied based on the distance between them. In a 5 MHz ultrasound imaging system using a 64-channel linear transducer, point reflector and speckle images with cysts of various brightness were synthesized and weights were applied to the ultrasound image. Using computer simulations, we confirmed that the side lobes were greatly reduced without affecting the spatial resolution in the point reflector image, and the contrast was significantly improved in the cyst image with computer simulations.

• Journal of Preventive Medicine and Public Health
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• v.34 no.4
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• pp.408-416
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• 2001

Objectives : To evaluate the diagnostic value of quantitative ultrasound (QUS) in the prediction of osteoporosis as defined by dual energy x-ray absorptiometry (DEXA) in postmenopausal women. Methods : Questionnaires and height and weight measurements were used in the investigation of 176 postmenopausal women. QUS measurements were taken on the right calcaneus while bone mineral density (BMD) measurements of the lumbar spine and femoral neck were made with DEXA. The areas under the curves (AUC) of the speed of sound (SOS) for osteoporosis in the lumbar spine and femoral neck were obtained through receiver operating characteristic (ROC) analysis and evaluated. A comparison was made, for osteoporosis in the lumbar spine and femoral neck, between the AUCs of the logistic model with clinical risk factors and SOS. Results : Pearson's correlation coefficients of SOS and lumbar spine BMD, and of SOS and femoral neck BMD were 0.26 and 0.37. The AUC for the logistic model in its discrimination for lumbar spine osteoporosis was 0.764, and for SOS 0.605. The AUCs for the logistic model in its discrimination for femoral neck osteoporosis and for SOS were 0.890 and 0.892, respectively. Conclusions : These results suggest that the diagnostic value of QUS as a screening tool for osteoporosis is moderate for the femoral neck, but merely low for the lumbar spine and that the predictability provided by SOS is no better than that by the sole use of clinical risk factors in postmenopausal women.

• Clinical Endoscopy
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• v.51 no.6
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• pp.600-601
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• 2018

• Journal of Yeungnam Medical Science
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• v.41 no.1
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• pp.56-57
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• 2024