• Journal of Biomedical Engineering Research
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• v.43 no.6
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• pp.390-398
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• 2022

Ultrasound examination using ultrasound equipment is an ultrasound device that images human organs using sound waves and is used in various areas such as diagnosis, follow-up, and treatment of diseases. However, if the quality of ultrasound equipment is not guaranteed, the possibility of misdiagnosis increases, and the diagnosis rate decreases. Accordingly, The Korean Society of Radiology and Korea society of Ultrasound in Medicine presented guidelines for quality management of ultrasound equipment using ATS-539 phantom. The DenseNet201 classification algorithm shows 99.25% accuracy and 5.17% loss in the Dead Zone, 97.52% loss in Axial/Lateral Resolution, 96.98% accuracy and 20.64% loss in Sensitivity, 93.44% accuracy and 22.07% loss in the Gray scale and Dynamic Range. As a result, it is the best and is judged to be an algorithm that can be used for quantitative evaluation. Through this study, it can be seen that if quantitative evaluation using artificial intelligence is conducted in the qualitative evaluation item of ultrasonic equipment, the reliability of ultrasonic equipment can be increased with high accuracy.

• Physical Therapy Korea
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• v.18 no.3
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• pp.8-15
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• 2011

Abdominal muscle plays a crucial role in postural control and respiration control. However, thickness of abdominal muscle in the paretic side of a hemiplegic patient has not been reported in previous studies. The purpose of this research was to compare lateral abdominal muscle thickness between the nonparetic and paretic side in patients with chronic stroke using rehabilitative ultrasound imaging. Twenty two patients with chronic stroke participated in this study. Absolute thickness of transversus abdominis (TrA), internal oblique (IO) and external oblique (EO) was measured at the end of inspiration and expiration during quiet breathing, and relative thickness was calculated (thickness of each muscle as a percentage of total muscle thickness). Ultrasound imaging was recorded three times and the average value was determined for statistical analysis. Differences in absolute and relative lateral abdominal muscle thickness between the nonparetic and paretic side were assessed with paired t-tests. Absolute muscle thickness of the paretic side TrA was thinner than that of the nonparetic side at the end of inspiration and expiration during quiet breathing. Relative muscle thickness of the paretic side TrA was thinner than the paretic side only at the end of expiration during quiet breathing (p>.05). Therefore, it is necessary to strength TrA in patients with chronic stroke during physical therapy intervention. Further study is needed whether physical therapy intervension will induce TrA thickness in patients with chronic stroke in prospective study design.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.368-373
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• 2009

A human tissue mimicking phantom is constructed to assess the performance of a medical ultrasound elasticity imaging system. In a human body, the tumor or cancer is stiffer than its surrounding normal tissue. A technique fur imaging the elasticity of such a tissue is referred to as elastography. Homogeneous elasticity phantoms with differing Young's moduli are constructed using a plastic hardener and softener to simulate the mechanical characteristics of a diseased human tissue. The Young's modulus of the fabricated homogeneous phantom materials were measured from 11.1 to 79.6 kPa depending on the mixing ratio of the amount of the hardener to that of the softener. An ultrasound lesion mimicking phantom was made of these materials, and ultrasound elasticity imaging was performed on it. It is confirmed in this paper that the fabricated plastic-based elasticity phantom is useful in representing the elastic characteristics of a human tissue.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.2
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• pp.69-76
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• 2020

In this paper, we introduce a method to visualize the contrast diffusion patterns and the dynamic vascular patterns in a contrast-enhanced ultrasound image sequence. We present an imaging technique to visualize parameters such as contrast arrival time, peak intensity time, and contrast decay time in contrast-enhanced ultrasound data. The contrast flow pattern and its velocity are important for characterizing focal liver lesions. We propose a method for representing the contrast diffusion patterns as an image. In the methods, respiratory motion may degrade the accuracy of the parametric images. Therefore, we present a respiratory motion tracking technique that uses dynamic weights and a momentum factor with respect to the respiration cycle. Through the experiment using 72 CEUS data sets, we show that the proposed method makes it possible to overcome the limitation of analysis by the naked eye and improves the reliability of the parametric images by compensating for respiratory motion in contrast-enhanced ultrasonography.

• Korean Journal of Digital Imaging in Medicine
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• v.16 no.2
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• pp.1-7
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• 2014

This study is to increase the accuracy of the diagnosis of benign prostatic hyperplasia by presenting a method that can accurately measure the residual urine amount of the bladder by using an ultrasound image. Agar powder, Propanol and distilled water were used as materials for making a phantom. In order to measure the volume, a $10m{\ell}$ cylinder, syringe and beaker were used. The image was obtained by scanning phantoms produced into six shapes. Each constant value was obtained by using the expression designed to measure the residual urine amount of the bladder and was compared and analyzed. The measuring method of Bladder volume was presented and a constant value for each shape was obtained and five observers measured it five times. According to the results of clinical application, the errors of Ellipse-beanbag, Shield-shield were 11.0%, 18.2%, respectively. Constant values depending on the shape of each phantom were presented in order to accurately measure the volume of the bladder in measuring the amount of residual urine for the diagnosis of benign prostatic hyperplasia. The accuracy of the volume using this was verified statistically(p > 0.05). Therefore, it is considered to be useful in diagnosing benign prostatic hyperplasia by using the ultrasound imaging measuring method presented.

• Korean Journal of Radiology
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• v.21 no.4
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• pp.442-449
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• 2020

Objective: To compare the diagnostic performance of contrast-enhanced spectral mammography (CESM) versus ultrasonography (US) in symptomatic patients with dense breasts, while using histology as the gold standard. Materials and Methods: After obtaining approval from the local ethics board, this prospective study collected data from patients with symptomatic breasts who underwent CESM and US examinations from May 1, 2017 to September 30, 2017. We then selected those with dense breasts and pathological results as our sample population. Both CESM and US results were classified by a radiologist through the Breast Imaging Reporting and Data System, and the results were compared with their corresponding histological results. The chi-square test was conducted to compare the diagnostic performance of CESM and US, and the receiver operating characteristic curves for the two imaging modalities were obtained. Results: A total of 131 lesions from 115 patients with dense breasts were included in this study. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were 93.8%, 88.1%, 88.2%, 93.7%, and 90.8% for CESM, and 90.6%, 82.1%, 82.9%, 90.2%, and 86.3% for US, respectively. The p values for sensitivity, specificity, PPV, NPV, and accuracy were 0.687, 0.388, 0.370, 0.702, and 0.238, respectively. The area under the curve of CESM (0.917) was comparable with that of US (0.884); however, the differences between CESM and US were not statistically significant (p = 0.225). Eight false-positive cases and 4 false-negative cases for breast cancer were found in CESM, while 12 false-positive cases and 6 false-negative cases were found in US. Conclusion: The diagnostic performances of CESM and US are comparable in symptomatic women with dense breasts; however, the routine use of additional US imaging is questionable for lesions that can be detected by CESM.

• Journal of the Korean Society of Radiology
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• v.81 no.5
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• pp.1069-1082
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• 2020

Coverage by National Health Insurance (NHI) was expanded in the abdominal imaging area as follows: upper abdominal ultrasound on April 1, 2018, lower abdominal ultrasound on February 1, 2019, and abdominal MRI on November 1, 2019. Many patients can benefit from the expansion of NHI coverage. Newly included diseases for NHI coverage includes liver cirrhosis, gallbladder polyps, hepatic adenoma/dysplastic nodules, pancreatic cysts, autoimmune pancreatitis and bile duct stone disease. However, the expansion of coverage made each examination more complex, including indications, follow-up strategy, the number of examination per patients, the standard images to be acquired, and the standard forms of the radiological report. Therefore, more careful consideration is mandatory when an abdominal imaging examination is prescribed and conducted.

• Investigative Magnetic Resonance Imaging
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• v.21 no.4
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• pp.252-258
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• 2017

Primary mesenteric liposarcoma is rare. It is difficult to make an accurate preoperative diagnosis of the myxoid type of liposarcoma by using imaging such as ultrasound or computed tomography (CT) due to the very small amount of fat that is located in the tumor. We report a case of primary myxoid liposarcoma of the mesentery which was difficult to differentiate from other solid mesenteric tumors with a myxoid component such as low grade fibromyxoid sarcoma, myxoid leiomyosarcoma or myxoma. Use of chemical shift magnetic resonance (MR) imaging to detect small fat components and its cystic appearance with solid components on the MR images can be useful to differentiate myxoid liposarcoma from the other mesenteric tumors with a myxoid component.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.6
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• pp.879-884
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• 2012

Photoacoustic Tomography (PAT) is a promising medical imaging modality by reason of its particularity. It combines optical imaging contrast of optical imaging with the spatial resolution of ultrasound imaging and can demonstrate change of biological feature in an image. For that reason, many studies are in progress to apply this technic for diagnosis. But, real-time PAT system is necessary to confirm a biological reaction induced by external stimulation immediately. Thus, we developed a real-time PAT system using linear array transducer and self-developed Data acquisition board (DAQ) resources, To evaluate the feasibility and performance of our proposed system, two type of phantom test were also performed. As a result of those experiments, the proposed system shows enough performance and confirm its usefulness.

• Investigative Magnetic Resonance Imaging
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• v.25 no.2
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• pp.135-140
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• 2021

Breast angiosarcoma is a very rare manifestation. Herein, we report a case of breast angiosarcoma in a 21-year-old woman admitted to our hospital with a one-year history of a palpable mass with fullness and swelling of the right breast. The various imaging findings, including mammography, ultrasound (US), and magnetic resonance imaging (MRI), of this rare disease are described. The imaging findings of US and combined MRI of breast angiosarcoma were specific in this case. The imaging characteristics could be helpful in detecting and diagnosing breast angiosarcoma in young women with a palpable mass with fullness and swelling of the breast.